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This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- == There are 65 instances of lines with non-ascii characters in the document. == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack a Security Considerations section. ** There are 1115 instances of too long lines in the document, the longest one being 4 characters in excess of 72. Miscellaneous warnings: ---------------------------------------------------------------------------- == Line 324 has weird spacing: '...emented by an...' == Line 372 has weird spacing: '... 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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 IP Storage Working Group Charles Monia 3 INTERNET DRAFT Rod Mullendore 4 Expires July 2002 Josh Tseng 5 Nishan Systems 7 Franco Travostino 8 Nortel Networks 10 David Robinson 11 Sun Microsystems 13 Wayland Jeong 14 Troika Networks 16 Rory Bolt 17 Quantum/ATL 19 Mark Edwards 20 Eurologic 22 January 2002 24 iFCP - A Protocol for Internet Fibre Channel Storage Networking 26 Status of this Memo 28 This document is an Internet-Draft and is in full conformance with 29 all provisions of Section 10 of RFC 2026 [RFC2026]. 31 Internet-Drafts are working documents of the Internet Engineering 32 Task Force (IETF), its areas, and its working groups. Note that 33 other groups may also distribute working documents as Internet- 34 Drafts. Internet-Drafts are draft documents valid for a maximum of 35 six months and may be updated, replaced, or obsoleted by other 36 documents at any time. It is inappropriate to use Internet-Drafts 37 as reference material or to cite them other than as "work in 38 progress." 40 The list of current Internet-Drafts can be accessed at 41 http://www.ietf.org/ietf/1id-abstracts.txt 43 The list of Internet-Draft Shadow Directories can be accessed at 44 http://www.ietf.org/shadow.html. 46 Comments 48 Comments should be sent to the ips mailing list (ips@ece.cmu.edu) 49 or to the author(s). 51 iFCP Revision 9 January 2002 53 Status of this Memo...................................................1 54 Comments..............................................................1 55 1. Abstract.....................................................4 56 2. About This Document..........................................4 57 2.1 Conventions used in this document............................4 58 2.2 Purpose of this document.....................................4 59 3. iFCP Introduction............................................4 60 3.1 Definitions..................................................5 61 4. Fibre Channel Communication Concepts.........................7 62 4.1 The Fibre Channel Network....................................7 63 4.2 Fabric Topologies............................................8 64 4.2.1 Switched Fibre Channel Fabrics...............................9 65 4.2.2 Mixed Fibre Channel Fabric..................................10 66 4.3 Fibre Channel Layers and Link Services......................11 67 4.3.1 Fabric-Supplied Link Services...............................12 68 4.4 Fibre Channel Nodes.........................................12 69 4.5 Fibre Channel Device Discovery..............................13 70 4.6 Fibre Channel Information Elements..........................13 71 4.7 Fibre Channel Frame Format..................................14 72 4.7.1 N_PORT Address Model........................................14 73 4.8 Fibre Channel Transport Services............................15 74 4.9 Login Processes.............................................16 75 5. The iFCP Network Model......................................16 76 5.1 Fibre Channel Fabric Topologies Supported by iFCP...........18 77 5.2 iFCP Transport Services.....................................18 78 5.2.1 Fibre Channel Transport Services Supported by iFCP..........18 79 5.3 iFCP Device Discovery and Configuration Management..........19 80 5.4 iFCP Fabric Properties......................................19 81 5.4.1 Address Transparency........................................20 82 5.4.2 Configuration Scalability...................................20 83 5.4.3 Fault Tolerance.............................................20 84 5.5 The iFCP N_PORT Address Model...............................21 85 5.5.1 Operation in Address Transparent Mode.......................22 86 5.5.2 Operation in Address Translation Mode.......................23 87 5.5.3 Address Translation.........................................24 88 6. iFCP Protocol...............................................27 89 6.1 Overview....................................................27 90 6.1.1 iFCP Transport Services.....................................27 91 6.1.2 iFCP Support for Link Services..............................28 92 6.2 TCP Stream Transport of iFCP Frames.........................29 93 6.2.1 iFCP Session Model..........................................29 94 6.2.2 iFCP Session Management.....................................29 95 6.2.3 Terminating an N_PORT Login Session.........................34 96 6.3 IANA Considerations.........................................35 97 6.4 Encapsulation of Fibre Channel Frames.......................35 98 6.4.1 Encapsulation Header Format.................................36 99 6.4.2 SOF and EOF Delimiter Fields................................39 100 6.4.3 Frame Encapsulation.........................................40 101 6.4.4 Frame De-encapsulation......................................40 102 7. TCP Session Control Messages................................41 103 7.1 Connection Bind (CBIND).....................................43 104 7.2 Unbind Connection (UNBIND)..................................46 105 iFCP Revision 9 January 2002 107 7.3 LTEST -- Test Connection Liveness...........................48 108 8. Fibre Channel Link Services.................................49 109 8.1 Special Link Service Messages...............................50 110 8.2 Link Services Requiring Payload Address Translation.........52 111 8.3 Fibre Channel Link Services Processed by iFCP...............54 112 8.3.1 Special Extended Link Services..............................55 113 8.3.2 Special FC-4 Link Services..................................68 114 8.4 FLOGI Service Parameters Supported by an iFCP Gateway.......70 115 9. iFCP Error Detection........................................72 116 9.1 Overview....................................................72 117 9.2 Stale Frame Prevention......................................72 118 9.2.1 Enforcing R_A_TOV Limits....................................73 119 10. Fabric Services Supported by an iFCP implementation.........75 120 10.1 F_PORT Server...............................................75 121 10.2 Fabric Controller...........................................75 122 10.3 Directory/Name Server.......................................75 123 10.4 Broadcast Server............................................76 124 10.4.1 Establishing the Broadcast Configuration....................76 125 10.4.2 Broadcast Session Management................................77 126 11. iFCP Security...............................................78 127 11.1 Overview....................................................78 128 11.2 iFCP Security Operating Requirements........................78 129 11.2.1 Context.....................................................78 130 11.2.2 Security Threats............................................78 131 11.2.3 Interoperability Requirements with Security Gateways........79 132 11.2.4 Statically and Dynamically Assigned IP Addresses............79 133 11.2.5 Authentication Requirements.................................79 134 11.2.6 Confidentiality Requirements................................80 135 11.2.7 Rekeying Requirements.......................................80 136 11.2.8 Usage Requirements..........................................80 137 11.2.9 iSNS Role...................................................80 138 11.3 iFCP Security Design........................................80 139 11.3.1 Enabling Technologies.......................................80 140 11.3.2 Use of IKE and IPsec........................................82 141 11.3.3 Signatures and Certificate-based authentication.............84 142 11.4 iSNS and iFCP Security......................................84 143 11.5 Use of iSNS to Distribute Security Policy...................85 144 11.6 Minimal Security Policy for an iFCP gateway.................86 145 12. Quality of Service Considerations...........................86 146 12.1 Minimal requirements........................................86 147 12.2 High-assurance..............................................86 148 13. Author's Addresses..........................................88 149 14. References..................................................89 150 14.1 Normative...................................................89 151 14.2 Non-Normative...............................................90 152 A. iFCP Support for Fibre Channel Link Services................92 153 A.1 Basic Link Services.........................................92 154 A.2 Link Services Processed Transparently.......................92 155 A.3 iFCP-Processed Link Services................................93 156 Full Copyright Statement.............................................96 157 iFCP Revision 9 January 2002 159 1. Abstract 161 This document specifies an architecture and gateway-to-gateway 162 protocol for the implementation of Fibre Channel fabric 163 functionality on a network in which TCP/IP switching and routing 164 elements replace Fibre Channel components. The protocol enables the 165 attachment of Fibre Channel devices to an IP network by supporting 166 the fabric services required by such devices. 168 2. About This Document 170 2.1 Conventions used in this document 172 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 173 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 174 this document are to be interpreted as described in RFC-2119 175 [RFC2119]. 177 All frame formats are in big endian network byte order. 179 2.2 Purpose of this document 181 This is a standards-track document, which specifies a protocol for 182 the implementation of Fibre Channel transport services on a TCP/IP 183 network. Some portions of this document contain material from 184 standards controlled by NCITS T10 and T11. This material is 185 included here for informational purposes only. The authoritative 186 information is given in the appropriate NCITS standards document. 188 The authoritative portions of this document specify the mapping of 189 standards-compliant fibre Channelprotocol implementations to 190 TCP/IP. This mapping includes sections of this document which 191 describe the "iFCP Protocol" (see section 6). 193 3. iFCP Introduction 195 iFCP is a gateway-to-gateway protocol, which provides Fibre Channel 196 fabric services to Fibre Channel devices over a TCP/IP network. 197 iFCP uses TCP to provide congestion control, error detection and 198 recovery. iFCP's primary objective is to allow interconnection and 199 networking of existing Fibre Channel devices at wire speeds over an 200 IP network. 202 The protocol and method of frame address translation described in 203 this document permit the attachment of Fibre Channel storage 204 devices to an IP-based fabric by means of transparent gateways. 206 The protocol achieves this transparency by allowing normal Fibre 207 Channel frame traffic to pass through the gateway directly, with 209 iFCP Revision 9 January 2002 211 provisions, where necessary, for intercepting and emulating the 212 fabric services required by a Fibre Channel device. 214 3.1 Definitions 216 Terms needed to clarify the concepts presented in this document are 217 presented here. 219 Locally Attached Device - With respect to a gateway, a Fibre 220 Channel device accessed through the Fibre Channel fabric to 221 which the gateway is attached. 223 Remotely Attached Device - With respect to a gateway, a Fibre 224 Channel device accessed from the gateway by means of the 225 iFCP protocol. 227 Address-translation mode � A mode of gateway operation in which the 228 scope of N_PORT fabric addresses for locally attached 229 devices are local to the iFCP gateway. 231 Address-transparent mode � A mode of gateway operation in which the 232 scope of N_PORT fabric addresses for all Fibre Channel 233 devices are unique to the bounded iFCP fabric to which the 234 gateway belongs. 236 Gateway Region � The portion of the iFCP storage network accessed 237 through an iFCP gateway. Fibre Channel devices in the 238 region consist of all Fibre Channel devices locally 239 attached to the gateway. 241 Unbounded iFCP Fabric - The union of two or more gateway regions 242 configured to interoperate together in address-translation 243 mode. 245 Bounded iFCP Fabric � The union of two or more gateway regions 246 configured to interoperate together in address-transparent 247 mode. 249 Fibre Channel Device - An entity implementing the functionality 250 accessed through an FC-4 application protocol. 252 Fibre Channel Node - A collection of one or more N_Ports controlled 253 by a level above the FC-2 layer. A node is attached to a 254 Fibre Channel fabric by means of the N_PORT interface 255 described in [FC-FS]. 257 Fibre Channel Network - A native Fibre Channel fabric and all 258 attached Fibre Channel nodes. 260 Fabric - The components of a network that provide the transport 261 services defined in [FC-FS]. A fabric may be implemented in 263 iFCP Revision 9 January 2002 265 the IP framework by means of the architecture and protocols 266 discussed in this document. 268 Fabric Port - The interface through which an N_PORT accesses a 269 Fibre Channel fabric. The type of fabric port depends on 270 the Fibre Channel fabric topology. In this specification, 271 all fabric port interfaces are considered to be 272 functionally equivalent. 274 FC-2 - The Fibre Channel transport services layer described in [FC- 275 FS]. 277 FC-4 - The Fibre Channel application layer. This layer is 278 functionally equivalent to the TCP/IP application layer. 280 iFCP Portal - An entity representing the point at which a logical 281 or physical iFCP device is attached to the IP network. The 282 network address of the iFCP portal consists of the IP 283 address and TCP port number. 285 N_PORT - An iFCP or Fibre Channel entity representing the interface 286 to Fibre Channel device functionality. This interface 287 implements the Fibre Channel N_PORT semantics specified in 288 [FC-FS]. Fibre Channel defines several variants of this 289 interface that depend on the Fibre Channel fabric topology. 290 As used in this document, the term applies equally to all 291 variants. 293 N_PORT fabric address - The address of an N_PORT within the Fibre 294 Channel fabric. 296 N_PORT ID -- The address of a locally attached N_PORT within a 297 gateway region. N_PORT I/Ds are assigned in accordance 298 with the Fibre Channel rules for address assignment 299 specified in [FC-FS]. 301 N_PORT Alias -- The N_PORT address assigned by a gateway to 302 represent a remote N_PORT accessed via the iFCP protocol. 303 When routing frame traffic in address translation mode, the 304 gateway automatically converts N_PORT aliases to N_PORT 305 network addresses and vice versa. 307 N_PORT Network Address - The address of an N_PORT in the iFCP 308 fabric. This address consists of the IP address and TCP 309 port number of the iFCP Portal and the N_PORT ID of the 310 locally attached Fibre Channel device. 312 F_PORT - The interface used by an N_PORT to access Fibre Channel 313 switched fabric functionality. 315 iFCP - The protocol discussed in this document. 317 iFCP Revision 9 January 2002 319 Logical iFCP Device - The abstraction representing a single Fibre 320 Channel device as it appears on an iFCP network. 322 iSNS - The server functionality and IP protocol which provides 323 storage name services in an iFCP network. Fibre Channel 324 Name services are implemented by an iSNS name server as 325 described in [ISNS]. 327 N_PORT Session - An association created when two N_PORTS have 328 executed a PLOGI operation. It is comprised of the N_PORTs 329 and TCP connection that carries traffic between them. 331 iFCP Frame - A Fibre Channel frame encapsulated in accordance with 332 the Common Encapsulation Specification [ENCAP] and this 333 specification. 335 Port Login (PLOGI) - The Fibre Channel Extended Link Service (ELS) 336 that establishes an N_PORT login session through the 337 exchange of identification and operation parameters between 338 an originating N_PORT and a responding N_PORT. 340 DOMAIN_ID � The value contained in the high-order byte of a 24-bit 341 N_PORT Fibre Channel address. 343 4. Fibre Channel Communication Concepts 345 Fibre Channel is a frame-based, serial technology designed for 346 peer-to-peer communication between devices at gigabit speeds and 347 with low overhead and latency. 349 This section contains a discussion of the Fibre Channel concepts 350 that form the basis for the iFCP network architecture and protocol 351 described in this document. Readers familiar with this material may 352 skip to section 5. 354 Material presented in this section is drawn from the following T11 355 specifications: 357 -- The Fibre Channel Framing and Signaling Interface, [FC-FS] 359 -- Fibre Channel Switch Fabric -2, [FC-SW2] 361 -- Fibre Channel Generic Services, [FC-GS3] 363 -- Fibre Channel Fabric Loop Attachment, [FC-FLA] 365 The reader will find an in-depth treatment of the technology in 366 [KEMCMP] and [KEMALP]. 368 4.1 The Fibre Channel Network 369 iFCP Revision 9 January 2002 371 The fundamental entity in Fibre Channel is the Fibre Channel 372 network. Unlike a layered network architecture, a Fibre Channel 373 network is largely specified by functional elements and the 374 interfaces between them. As shown in Figure 1, these consist, in 375 part, of the following: 377 a) N_PORTs -- The end points for Fibre Channel traffic. In the FC 378 standards, N_PORT interfaces have several variants, depending on 379 the topology of the fabric to which they are attached. As used 380 in this specification, the term applies to any one of the 381 variants. 383 b) FC Devices � The Fibre Channel devices to which the N_PORTs 384 provide access. 386 c) Fabric Ports -� The interface within a fabric that provides Fibre 387 Channel attachment for an N_PORT. The types of fabric port 388 depend on the fabric topology and are discussed in section 4.2. 390 d) The fabric infrastructure for carrying frame traffic between 391 N_PORTs. 393 e) Within a switched or mixed fabric (see section 4.2), a set of 394 auxiliary servers, including a name server for device discovery 395 and network address resolution. The types of service depend on 396 the network topology. 398 +--------+ +--------+ +--------+ +--------+ 399 | FC | | FC | | FC | | FC | 400 | Device | | Device |<-------->| Device | | Device | 401 |........| |........| |........| |........| 402 | N_PORT | | N_PORT | | N_PORT | | N_PORT | 403 +---+----+ +----+---+ +----+---+ +----+---+ 404 | | | | 405 +---+----+ +----+---+ +----+---+ +----+---+ 406 | Fabric | | Fabric | | Fabric | | Fabric | 407 | Port | | Port | | Port | | Port | 408 +========+===+========+==========+========+==+========+ 409 | Fabric | 410 | & | 411 | Fabric Services | 412 +-----------------------------------------------------+ 413 Figure 1 -- A Fibre Channel Network 415 The following sections describe Fibre Channel fabric topologies and 416 give an overview of the Fibre Channel communications model. 418 4.2 Fabric Topologies 420 The principal Fibre Channel fabric topologies consist of the 421 following: 423 iFCP Revision 9 January 2002 425 a) Arbitrated Loop -- A series of N_PORTs connected together in 426 daisy-chain fashion. Data transmission between N_PORTs 427 requires arbitration for control of the loop in a manner 428 similar to a token ring network. 430 b) Switched Fabric -- A fabric consisting of switching elements, 431 as described in section 4.2.1. 433 c) Mixed Fabric -- A fabric consisting of switches and "fabric- 434 attached" loops. A description can be found in [FC-FLA]. 436 Depending on the topology, the N_PORT and fabric port variants 437 through which a Fibre Channel device is attached to the network may 438 be one of the following: 440 Fabric Topology Fabric Port Type N_PORT Variant 441 --------------- ---------------- -------------- 443 Loop L_PORT NL_PORT 445 Switched F_PORT N_PORT 447 Mixed FL_PORT NL_PORT 449 F_PORT N_PORT 451 The differences in each N_PORT variant and its corresponding fabric 452 port are confined to the interactions between them. To an external 453 N_PORT, all fabric ports are transparent and all remote N_PORTs are 454 functionally identical. 456 4.2.1 Switched Fibre Channel Fabrics 458 An example of a multi-switch Fibre Channel fabric is shown below. 460 iFCP Revision 9 January 2002 462 +----------+ +----------+ 463 | FC | | FC | 464 | Device | | Device | 465 |..........| |..........| 466 | N_PORT |<........>| N_PORT | 467 +----+-----+ +-----+----+ 468 | | 469 +----+-----+ +-----+----+ 470 | F_PORT | | F_PORT | 471 ==========+==========+==========+==========+============== 472 | FC | | FC | 473 | Switch | | Switch | 474 +----------+ +----------+ Fibre Channel 475 |Inter- | |Inter- | Fabric 476 |Switch | |Switch | 477 |Interface | |Interface | 478 +-----+----+ +-----+----+ 479 | | 480 | | 481 +-----+----+----------+-----+----+ 482 |Inter- | |Inter- | 483 |Switch | |Switch | 484 |Interface | |Interface | 485 +----------+ +----------+ 486 | FC Switch | 487 | | 488 +--------------------------------+ 489 Figure 2 -- Multi-Switch Fibre Channel Fabric 491 The interface between switch elements is either proprietary or the 492 standards-compliant E_PORT interface described by the FC-SW2 493 specification, [FC-SW2]. 495 4.2.2 Mixed Fibre Channel Fabric 497 A mixed fabric contains one or more arbitrated loops connected to a 498 switched fabric as shown in Figure 3. 500 iFCP Revision 9 January 2002 502 +----------+ +----------+ +---------+ 503 | FC | | FC | | FC | 504 | Device | | Device | | Device | 505 |..........| |..........| |.........| 506 | N_PORT |<........>| NL_PORT +---+ NL_PORT | 507 +----+-----+ +-----+----+ +----+----+ 508 | | FC Loop | 509 +----+-----+ +-----+----+ | 510 | F_PORT | | FL_PORT +--------+ 511 | | | | 512 ==========+==========+==========+==========+============== 513 | FC | | FC | 514 | Switch | | Switch | 515 +----------+ +----------+ 516 |Inter- | |Inter- | 517 |Switch | |Switch | 518 |Interface | |Interface | 519 +-----+----+ +-----+----+ 520 | | 521 | | 522 +-----+----+----------+-----+----+ 523 |Inter- | |Inter- | 524 |Switch | |Switch | 525 |Interface | |Interface | 526 +----------+ +----------+ 527 | FC Switch | 528 | | 529 +--------------------------------+ 530 Figure 3 -- Mixed Fibre Channel Fabric 532 As noted previously, the protocol for communications between peer 533 N_PORTs is independent of the fabric topology, N_PORT variant and 534 type of fabric port to which an N_PORT is attached. 536 4.3 Fibre Channel Layers and Link Services 538 Fibre channel consists of the following layers: 540 FC-0 -- The interface to the physical media, 542 FC-1 �- The encoding and decoding of data and out-of-band physical 543 link control information for transmission over the physical media, 545 FC-2 �- The transfer of frames, sequences and Exchanges comprising 546 protocol information units. 548 FC-3 �- Common Services, 550 FC-4 �- Application protocols, such as FCP, the Fibre Channel SCSI 551 protocol. 553 iFCP Revision 9 January 2002 555 In addition to the layers defined above, Fibre Channel defines a 556 set of auxiliary operations, some of which are implemented within 557 the transport layer fabric, called link services. These are 558 required to manage the Fibre Channel environment, establish 559 communications with other devices, retrieve error information, 560 perform error recovery and other similar services. Some link 561 services are executed by the N_PORT. Others are implemented 562 internally within the fabric. These internal services are 563 described in the next section. 565 4.3.1 Fabric-Supplied Link Services 567 Servers internal to a switched fabric handle certain classes of 568 Link Service requests and service-specific commands. The servers 569 appear as N_PORTs located at the 'well-known' N_PORT fabric 570 addresses specified in [FC-FS]. Service requests use the standard 571 Fibre Channel mechanisms for N_PORT-to-N_PORT communications. 573 All switched fabrics must provide the following services: 575 Fabric F_PORT server � Services an N_PORT request to access the 576 fabric for communications. 578 Fabric Controller -- Provides state change information to inform 579 other FC devices when an N_PORT exits or enters the fabric (see 580 section 4.5). 582 Directory/Name Server � Allows N_PORTs to register information 583 in a database, retrieve information about other N_PORTs and 584 discover other devices as described in section 4.5. 586 A switched fabric may also implement the following optional 587 services: 589 Broadcast Address/Server �- Transmits single-frame, class 3 590 sequences to all N_PORTs. 592 Time Server �- Intended for the management of fabric-wide 593 expiration timers or elapsed time values and is not intended for 594 precise time synchronization. 596 Management Server � Collects and reports management information, 597 such as link usage, error statistics, link quality and similar 598 items. 600 Quality of Service Facilitator � Performs fabric-wide bandwidth 601 and latency management. 603 4.4 Fibre Channel Nodes 605 A Fibre Channel node has one or more fabric-attached N_PORTs. The 606 node and its N_PORTs have the following associated identifiers: 608 iFCP Revision 9 January 2002 610 a) A world-wide unique identifier for the node, 612 b) A world-wide unique identifier for each N_PORT associated with 613 the nodee, 615 c) For each N_PORT attached to a fabric, a 24-bit fabric-unique 616 address having the properties defined in section 4.7.1. The 617 fabric address is the address to which frames are sent. 619 Each world-wide unique identifier is a 64-bit binary quantity 620 having the format defined in [FC-FS]. 622 4.5 Fibre Channel Device Discovery 624 In a switched or mixed fabric, fibre channel devices and changes in 625 the device configuration may be discovered by means of services 626 provided by the Fibre Channel Name Server and Fabric Controller. 628 The Name Server provides registration and query services that allow 629 a Fibre Channel device to register its presence on the fabric and 630 discover the existence of other devices. For example, one type of 631 query obtains the fabric address of an N_PORT from its 64-bit 632 world-wide unique name. The full set of supported Fibre Channel 633 Name Server queries is specified in [FC-GS3]. 635 The Fabric Controller complements the static discovery capabilities 636 provided by the Name Server through a service that dynamically 637 alerts a Fibre Channel device whenever an N_PORT is added or 638 removed from the configuration. A Fibre Channel device receives 639 these notifications by subscribing to the service as specified in 640 [FC-FS]. 642 4.6 Fibre Channel Information Elements 644 The fundamental element of information in Fibre Channel is the 645 frame. A frame consists of a fixed header and up to 2112 bytes of 646 payload having the structure described in section 4.7. The maximum 647 frame size that may be transmitted between a pair of Fibre Channel 648 devices is negotiable up to the payload limit, based on the size of 649 the frame buffers in each Fibre Channel device and the path MTU 650 supported by the fabric. 652 Operations involving the transfer of information between N_PORT 653 pairs are performed through 'Exchanges'. In an Exchange, 654 information is transferred in one or more ordered series of frames 655 referred to as Sequences. 657 Within this framework, an upper layer protocol is defined in terms 658 of transactions carried by Exchanges. Each transaction, in turn, 659 consists of protocol information units, each of which is carried by 660 an individual Sequence within an Exchange. 662 iFCP Revision 9 January 2002 664 4.7 Fibre Channel Frame Format 666 A Fibre Channel frame consists of a header, payload and 32-bit CRC 667 bracketed by SOF and EOF delimiters. The header contains the 668 control information necessary to route frames between N_PORTs and 669 manage Exchanges and Sequences. The following diagram gives a 670 highly simplified view of the frame. 672 +-----------------------------+ 673 | Start-of-frame Delimiter | 674 +-----+-----------------------+<----+ 675 | | Destination N_PORT | | 676 | | Fabric Address (D_ID) | | 677 | | (24-bits) | | 678 +-----+-----------------------+ 24-byte 679 | | Source N_PORT | Frame 680 | | Fabric Address (S_ID) | Header 681 | | (24 bits) | | 682 +-----+-----------------------+ | 683 | Control information for | | 684 | frame type, Exchange | | 685 | management, IU | | 686 | segmentation and | | 687 | re-assembly | | 688 +-----------------------------+<----+ 689 | | 690 | Frame payload | 691 | (0 � 2112 bytes) | 692 | | 693 | | 694 | | 695 +-----------------------------+ 696 | CRC | 697 +-----------------------------+ 698 | End-of-Frame Delimiter | 699 +-----------------------------+ 700 Figure 4 -- Fibre Channel Frame Format 702 The source and destination N_PORT fabric addresses embedded in the 703 S_ID and D_ID fields represent the physical MAC addresses of 704 originating and receiving N_PORTs. 706 4.7.1 N_PORT Address Model 708 N_PORT fabric addresses are 24-bit values having the following 709 format defined by the Fibre Channel specification [FC-FS]: 711 iFCP Revision 9 January 2002 713 Bit 23 16 15 8 7 0 714 +-----------+------------+----------+ 715 | Domain ID | Area ID | Port ID | 716 +-----------+------------+----------+ 717 Figure 5 -- Fibre Channel Address Format 719 A Fibre Channel device acquires an address when it logs into the 720 fabric. Such addresses are volatile and subject to change based on 721 modifications in the fabric configuration. 723 In a Fibre Channel fabric, each switch element has a unique Domain 724 I/D assigned by the principal switch. The value of the Domain I/D 725 ranges from 1 to 239 (0xEF). Each switch element, in turn, 726 administers a block of addresses divided into area and port IDs. An 727 N_PORT connected to a F_PORT receives a unique fabric address 728 consisting of the switch�s Domain I/D concatenated with switch- 729 assigned area and port I/Ds. 731 A loop-attached NL_PORT (see Figure 3) obtains the Port ID 732 component of its address during the loop initialization process 733 described in [FC-AL2]. The area and domain I/Ds are supplied by the 734 fabric when the FLOGI is executed. 736 4.8 Fibre Channel Transport Services 738 N_PORTs communicate by means of the following classes of service 739 specified in the Fibre Channel standard ([FC-FS]): 741 Class 1 � A dedicated physical circuit connecting two N_PORTs. 743 Class 2 � A frame-multiplexed connection with end-to-end flow 744 control and delivery confirmation. 746 Class 3 � A frame-multiplexed connection with no provisions for 747 end-to-end flow control or delivery confirmation. 749 Class 4 - A connection-oriented service, based on a virtual circuit 750 model, providing confirmed delivery with bandwidth and latency 751 guarantees. 753 Class 6 - A reliable multicast service derived from class 1. 755 Class 2 and class 3 are the predominant services supported by 756 deployed Fibre Channel storage and clustering systems. 758 Class 3 service is similar to UDP or IP datagram service. Fibre 759 channel storage devices using this class of service rely on the ULP 760 implementation to detect and recover from transient device and 761 transport errors. 763 For class 2 and class 3 service, the Fibre Channel fabric is not 764 required to provide in-order delivery of frames unless explicitly 766 iFCP Revision 9 January 2002 768 requested by the frame originator (and supported by the fabric). If 769 ordered delivery is not in effect, it is the responsibility of the 770 frame recipient to reconstruct the order in which frames were sent 771 based on information in the frame header. 773 4.9 Login Processes 775 The Login processes are the means whereby an N_PORT establishes the 776 operating environment necessary to communicate with the fabric, 777 other N_PORTs and ULP implementations accessed via the N_PORT. 778 Three login operations are supported: 780 a) Fabric Login (FLOGI) -- An operation whereby the N_PORT 781 registers its presence on the fabric, obtains fabric 782 parameters, such as classes of service supported, and receives 783 its N_PORT address, 785 b) Port Login (PLOGI) -- An operation by which an N_PORT 786 establishes communication with another N_PORT. 788 c) Process Login (PRLOGI) -- An operation which establishes the 789 process-to-process communications associated with a specific 790 FC-4 ULP -- such as FCP-2, the Fibre Channel SCSI mapping. 792 Since N_PORT addresses are volatile, an N_PORT originating a login 793 (PLOGI) operation executes a Name Server query to discover the 794 Fibre Channel address of the remote device. A common query type 795 involves use of the world-wide unique name of an N_PORT to obtain 796 the 24-bit N_PORT Fibre Channel address to which the PLOGI request 797 is sent. 799 5. The iFCP Network Model 801 The iFCP protocol enables the implementation of Fibre Channel mixed 802 or switched fabric functionality on an IP network in which IP 803 components and technology replace the Fibre Channel switching and 804 routing infrastructure described in section 4.2. 806 The example of Figure 6 shows a Fibre Channel fabric with attached 807 devices. These access the fabric through an N_PORT interface 808 connected to a Fabric Port whose behavior is specified in [FC-FS]. 809 In this case, the N_PORT and Fabric Port represent any of the 810 variants described in section 4.2. 812 Within the Fibre Channel device domain, fabric-addressable entities 813 consist of other N_PORTs and devices internal to the fabric that 814 perform the fabric services defined in [FC-GS3]. 816 iFCP Revision 9 January 2002 818 Fibre Channel Network 819 +--------+ +--------+ 820 | FC | | FC | 821 | Device | | Device | 822 |........| |........| Fibre Channel 823 | N_PORT |<......>| N_PORT | Device Domain 824 +---+----+ +----+---+ ^ 825 | | | 826 +---+----+ +----+---+ | 827 | Fabric | | Fabric | | 828 | Port | | Port | | 829 ==========+========+========+========+============== 830 | Fabric & | | 831 | Fabric Services | v 832 | | Fibre Channel 833 +--------------------------+ Fabric Domain 834 Figure 6 -- A Fibre Channel Fabric 836 Gateway Region Gateway Region 837 +--------+ +--------+ +--------+ +--------+ 838 | FC | | FC | | FC | | FC | 839 | Device | | Device | Fibre | Device | | Device | Fibre 840 |........| |........| Channel |........| |........| Channel 841 | N_PORT | | N_PORT |<.........>| N_PORT | | N_PORT | Device 842 +---+----+ +---+----+ Traffic +----+---+ +----+---+ Domain 843 | | | | ^ 844 +---+----+ +---+----+ +----+---+ +----+---+ | 845 | Fabric | | Fabric | | Fabric | | Fabric | | 846 | Port | | Port | | Port | | Port | | 847 =+========+==+========+===========+========+==+========+========== 848 | iFCP Layer |<--------->| iFCP Layer | | 849 |....................| ^ |....................| | 850 | iFCP Portal | | | iFCP Portal | v 851 +--------+-----------+ | +----------+---------+ IP 852 iFCP|Gateway Control iFCP|Gateway Network 853 | Data | 854 | | 855 | | 856 |<------Encapsulated Frames------->| 857 | +------------------+ | 858 | | | | 859 +------+ IP Network +--------+ 860 | | 861 +------------------+ 862 Figure 7 -- An iFCP Fabric 864 Figure 7 shows an implementation of an equivalent iFCP fabric 865 consisting of two gateways, each in control of a single gateway 866 region. 868 iFCP Revision 9 January 2002 870 Each iFCP gateway contains two standards-compliant fibre channel 871 ports and an iFCP Portal for attachment to the IP network. Fibre 872 Channel devices in the region are those locally connected to the 873 iFCP fabric through the gateway fabric ports. 875 Looking into the fabric port, the gateway appears as a Fibre 876 Channel switch element. At this interface, remote N_PORTs are 877 presented as fabric-attached devices. Conversely, on the IP network 878 side, the gateway presents each locally connected N_PORT as a 879 logical Fibre Channel device. 881 5.1 Fibre Channel Fabric Topologies Supported by iFCP 883 A property of this architecture, not shown in the examples, is that 884 the Fibre Channel fabric configuration and topology within the 885 gateway region are invisible to the IP network and other gateway 886 regions. That is, the topology in the gateway region, whether it 887 is loop- or switch-based, is hidden from the IP network and from 888 other gateway regions. As a result, support for specific FC fabric 889 topologies becomes a gateway implementation issue. In such cases, 890 the gateway may implement any standards-compliant Fibre Channel 891 interface by incorporating the functionality required to present 892 locally attached N_PORTs as logical iFCP devices. 894 5.2 iFCP Transport Services 896 N_PORT to N_PORT communications that traverse a TCP/IP network 897 require the intervention of the iFCP layer within the gateway. This 898 consists of the following operations: 900 a) Execution of the frame addressing and mapping functions 901 described in section 5.5. 903 b) Execution of fabric-supplied link services addressed to one of 904 the well-known Fibre Channel N_PORT addresses. 906 c) Encapsulation of Fibre Channel frames for injection into the 907 TCP/IP network and de-encapsulation of Fibre Channel frames 908 received from the TCP/IP network. 910 d) Establishment of an N_PORT login session in response to a PLOGI 911 directed to a remote device. 913 The following sections discuss the frame addressing mechanism and 914 the way in which it is used to achieve communications transparency 915 between N_PORTs. 917 5.2.1 Fibre Channel Transport Services Supported by iFCP 919 An iFCP fabric supports Class 2 and Class 3 Fibre Channel transport 920 services as specified in [FC-FS]. An iFCP fabric does not support 921 class 4, class 6 or the Class 1 (dedicated connection) service. An 923 iFCP Revision 9 January 2002 925 N_PORT discovers the classes of transport services supported by the 926 fabric during fabric login. 928 5.3 iFCP Device Discovery and Configuration Management 930 An iFCP implementation performs device discovery and iFCP fabric 931 management. through the Internet Storage Name Service defined in 932 [ISNS]. Access to an iSNS server is required to perform the 933 following functions: 935 a) Emulation of the services provided by the Fibre Channel name 936 server described in section 4.3.1, including a mechanism for 937 asynchronously notifying an N_PORT of changes in the iFCP fabric 938 configuration, 940 b) Aggregation of gateways into iFCP fabrics for interoperation, 942 c) Segmentation of an iFCP fabric into Fibre Channel zones through 943 the definition and management of device discovery scopes, 944 referred to as 'discovery domains', 946 d) Storage and distribution of security policies as described in 947 section 11.2.9. 949 e) Implementation of the Fibre Channel broadcast mechanism. 951 5.4 iFCP Fabric Properties 953 A collection of iFCP gateways may be configured for interoperation 954 as either a bounded or unbounded iFCP fabric. 956 Gateways in a bounded iFCP fabric operate in address transparent 957 mode as described in section 5.5.1. In this mode, the scope of a 958 Fibre Channel N_PORT address is fabric-wide and is derived from 959 domain I/Ds issued by the iSNS server from a common pool. As 960 discussed below, the maximum number of domain I/Ds allowed by Fibre 961 Channel limits the configuration of a bounded iFCP fabric. 963 Gateways in an unbounded iFCP fabric operate in address translation 964 mode as described in section 5.5.2. In this mode, the scope of an 965 N_PORT address is local to a gateway region. For Fibre Channel 966 traffic between regions, the translation of frame-embedded N_PORT 967 addresses is performed by the gateway. As discussed below, an 968 unbounded iFCP fabric may have any number of switch elements and 969 gateways. 971 All iFCP gateways MUST support unbounded iFCP fabrics. Support for 972 bounded iFCP fabrics is OPTIONAL. 974 The decision to support bounded iFCP fabrics in a gateway 975 implementation depends on the address transparency, configuration 976 scalability, and fault tolerance considerations discussed below. 978 iFCP Revision 9 January 2002 980 5.4.1 Address Transparency 982 Although iFCP gateways in an unbounded fabric will convert N_PORT 983 addresses in the frame header and payload of standard link service 984 messages, a gateway cannot convert such addresses in the payload of 985 vendor- or user-specific Fibre Channel frame traffic. 987 Consequently, while both bounded and unbounded iFCP fabrics support 988 the standards-compliant FC-4 protocols and link services used by 989 mainstream Fibre Channel applications, a bounded iFCP fabric may 990 also support vendor- or user-specific protocol and link service 991 implementations that carry N_PORT I/Ds in the frame payload. 993 5.4.2 Configuration Scalability 995 The scalability limits of a bounded fabric configuration are a 996 consequence of the Fibre Channel address allocation policy 997 previously discussed. As noted, a bounded iFCP fabric using this 998 address allocation scheme is limited to a combined total of 238 999 gateways and Fibre Channel switch elements. As the system expands, 1000 the network may grow to include many switch elements and gateways, 1001 each of which controls a small number of devices. In this case, 1002 the limitation in switch and gateway count may become a barrier to 1003 extending and fully integrating the storage network. 1005 Since N_PORT Fibre Channel addresses in an unbounded iFCP fabric 1006 are not fabric-wide, there are no architectural limits on the 1007 number of iFCP gateways, Fibre Channel devices and switch elements 1008 that may be internetworked. In exchange for improved scalability, 1009 however, implementations must consider the incremental overhead of 1010 address conversion as well as the address transparency issues 1011 discussed in section 5.4.1. 1013 5.4.3 Fault Tolerance 1015 In an unbounded iFCP fabric, limiting the scope of an N_PORT 1016 address to a gateway region reduces the likelihood that 1017 reassignment of domain I/Ds caused by a disruption in one gateway 1018 region will cascade to others. 1020 In addition, a bounded iFCP fabric has an increased dependency on 1021 the iSNS server, which must act as the central address assignment 1022 authority. If connectivity with the server is lost, new DOMAIN_ID 1023 values cannot be automatically allocated as gateways and Fibre 1024 Channel switch elements are added to the fabric. 1026 Finally, adding a gateway to a bounded fabric is more likely to 1027 disrupt the operation of all devices in the gateway region along 1028 with those already in the fabric as new, fabric-wide N_PORT 1029 addresses are assigned. Furthermore, before the new gateway can be 1030 merged, its iSNS server must be slaved to the iSNS server in the 1031 bounded fabric to centralize the issuance of domain I/Ds. 1033 iFCP Revision 9 January 2002 1035 In contrast, adding a new gateway to an unbounded iFCP fabric can 1036 be done non-disruptively and requires only that new gateway's iSNS 1037 server import client attributes from the other iSNS servers. 1039 5.5 The iFCP N_PORT Address Model 1041 This section discusses iFCP extensions to the Fibre Channel 1042 addressing model of section 4.7.1, which are required for the 1043 transparent routing of frames between locally and remotely attached 1044 N_PORTs. 1046 In the iFCP protocol, an N_PORT is represented by the following 1047 addresses: 1049 a) A 24-bit N_PORT I/D. The Fibre Channel N_PORT address of a 1050 locally attached device. Depending on the gateway addressing 1051 mode, the scope is either local to a region or fabric-wide. In 1052 either mode, communications between N_PORTs in the same gateway 1053 region use the N_PORT I/D. 1055 b) A 24-bit N_PORT alias. An address assigned by a gateway 1056 operating in address translation mode to identify a remotely 1057 attached N_PORT. Frame traffic is directed to a remotely 1058 attached N_PORT by means of the N_PORT alias. 1060 c) An N_PORT network address. A tuple consisting of the gateway IP 1061 address, TCP port number and N_PORT I/D. The N_PORT network 1062 address identifies the source and destination N_PORTs for Fibre 1063 Channel traffic on the IP network. 1065 To provide transparent communications between remote and local 1066 N_PORTs, a gateway in address translation mode maintains an 1067 association between the remote N_PORT alias and the remote device's 1068 N_PORT network address. To establish this association the iFCP 1069 gateway assigns and manages Fibre Channel N_PORT fabric addresses 1070 as described in the following paragraphs. 1072 In an iFCP fabric, the iFCP gateway performs the address assignment 1073 and frame routing functions of an FC switch element. Unlike an FC 1074 switch, however, an iFCP gateway must also direct frames to 1075 external devices attached to remote gateways on the IP network. 1077 In order to be transparent to FC devices, the gateway must deliver 1078 such frames using only the 24-bit destination address in the frame 1079 header. By exploiting its control of address allocation and access 1080 to frame traffic entering or leaving the gateway region, it is able 1081 to achieve the necessary transparency. 1083 N_PORT addresses within a gateway region may be allocated in one of 1084 two ways: 1086 iFCP Revision 9 January 2002 1088 a) Address Translation Mode � A mode of N_PORT address assignment 1089 in which the scope of an N_PORT address is unique to the gateway 1090 region. The address of a remote device is represented in that 1091 gateway region by its gateway assigned N_PORT alias. 1093 b) Address Transparent Mode � A mode of N_PORT address assignment 1094 in which the scope of an N_PORT address is unique across the set 1095 of gateway regions comprising a bounded iFCP fabric. 1097 In address transparent mode, gateways within a bounded fabric 1098 cooperate in the assignment of addresses to locally attached 1099 N_PORTs. Each gateway in control of a region is responsible for 1100 obtaining and distributing unique domain I/Ds from the address 1101 assignment authority as described in section 5.5.1.1. Consequently, 1102 within the scope of a bounded fabric, the address of each N_PORT is 1103 unique. For that reason, gateway-assigned aliases are not required 1104 to represent remote N_PORTs. 1106 All iFCP implementations MUST support operation in address 1107 translation mode. Implementation of address transparent mode is 1108 OPTIONAL but MUST be provided if bounded iFCP fabric configurations 1109 are to be supported. 1111 The mode of gateway operation is settable in an implementation- 1112 specific manner. The implementation MUST NOT allow the mode to be 1113 changed after the gateway begins processing fibre channel frame 1114 traffic. 1116 5.5.1 Operation in Address Transparent Mode 1118 The following considerations and requirements apply to this mode of 1119 operation: 1121 a) iFCP gateways in address transparent mode will not interoperate 1122 with iFCP gateways that are not in transparent mode. 1124 b) When interoperating with locally attached Fibre Channel switch 1125 elements, each iFCP gateway MUST assume control of DOMAIN_ID 1126 assignments in accordance with the appropriate Fibre Channel 1127 standard or vendor-specific protocol specification. As 1128 described in section 5.5.1.1, DOMAIN_ID values assigned to FC 1129 switches in attached fabrics must be issued by the iSNS server. 1131 c) When operating in address transparent Mode, no Fibre Channel 1132 address translation SHALL take place. 1134 The process for establishing the TCP/IP context associated with an 1135 N_PORT login session in this mode is similar to that specified for 1136 address translation mode (section 5.5.2). 1138 5.5.1.1 Transparent Mode Domain I/D Management 1139 iFCP Revision 9 January 2002 1141 As described above, each gateway and Fibre Channel switch in a 1142 bounded iFCP fabric MUST have a unique domain I/D. In a gateway 1143 region containing Fibre Channel switch elements, each element 1144 obtains a domain I/D by querying the principal switch as described 1145 in [FC-SW2]-- \* MERGEFORMAT in this case the iFCP gateway itself. 1146 The gateway in turn may obtain domain I/Ds on demand from the iSNS 1147 name server acting as the central address allocation authority . In 1148 effect, the iSNS server assumes the role of master switch for the 1149 bounded fabric. In that case, the iSNS database contains: 1151 a) The definition for one or more bounded iFCP fabrics, 1153 b) For each bounded fabric, a world-wide unique name identifying 1154 each gateway in the fabric. A gateway in address transparent 1155 mode MUST reside in one and only one bounded fabric. 1157 In its role as principle switch, an iFCP gateway in address 1158 transparent mode SHALL obtain domain I/Ds for use in the gateway 1159 region by issuing the appropriate iSNS query using its world-wide 1160 name. 1162 5.5.1.2 Incompatibility with Address Translation Mode 1164 iFCP gateways in address transparent mode SHALL NOT originate or 1165 accept frames that do not have the TRN bit set to one in the iFCP 1166 flags field of the encapsulation header (see section 6.4.1). The 1167 iFCP gateway SHALL immediately terminate all N_PORT login sessions 1168 with the iFCP gateway from which it receives such frames. 1170 5.5.2 Operation in Address Translation Mode 1172 This section describes the process for managing the assignment of 1173 addresses within a gateway region, including the modification of FC 1174 frame addresses embedded in the frame header for frames sent and 1175 received from remotely attached N_PORTs. 1177 As described in section 5.5, the scope of N_PORT addresses in this 1178 mode is local to the gateway region. A principal switch within the 1179 gateway region, possibly the iFCP gateway itself, oversees the 1180 assignment of such addresses in accordance with the rules specified 1181 in [FC-FS] and [FC-FLA]. 1183 The assignment of N_PORT addresses to locally attached devices is 1184 controlled by the switch element to which the device is connected. 1186 When a remotely attached N_PORT is accessed, the gateway assigns a 1187 locally significant N_PORT alias. This alias is used in place of 1188 the N_PORT I/D assigned by the remote gateway. To perform address 1189 conversion and enable the appropriate routing, the gateway 1190 maintains a table mapping N_PORT aliases to the appropriate TCP/IP 1191 connection context and N_PORT ID of all remotely accessed N_PORTs. 1193 iFCP Revision 9 January 2002 1195 The means by which translation table entries are created and 1196 updated are described in section 5.5.3. 1198 5.5.3 Address Translation 1200 This section describes how address translation SHALL be performed 1201 by a gateway operating in address translation mode. For descriptive 1202 purposes, the gateway is assumed to maintain a table containing one 1203 entry for each remotely attached N_PORT as shown in Figure 8. 1205 +--------------------------------+ 1206 | Network Address of Remote | 1207 | Gateway | 1208 +--------------------------------+ 1209 | N_PORT I/D of Remote N_PORT | 1210 +--------------------------------+ 1211 | N_PORT Alias | 1212 +--------------------------------+ 1213 | N_PORT World-wide Unique Name | 1214 +--------------------------------+ 1215 Figure 8 -- Address Translation Table Entry for Remote N_PORT 1217 Each entry contains the following information: 1219 Network Address of Remote Gateway -- IP address and TCP port 1220 number of the gateway to which the remote device is attached. 1222 N_PORT I/D -- N_PORT address assigned to the remote device by 1223 the remote iFCP gateway. 1225 N_PORT Alias -- N_PORT address assigned to the remote device by 1226 the 'local' iFCP gateway. 1228 N_PORT World-wide Unique Name -- 64-bit N_PORT world wide name 1229 as specified in [FC-FS]. 1231 An iFCP gateway SHALL have one and only one entry for each remotely 1232 attached N_PORT it accesses. If an entry does not exist, one SHALL 1233 be built in response to one of the following transactions: 1235 a) A Fibre Channel Name Server request issued by a locally-attached 1236 N_PORTs as part of Fibre Channel device discovery (see section 1237 4.5) or, 1239 b) An N_PORT PLOGI request received from the remote Fibre Channel 1240 device (see section 8.3.1.7). 1242 An iFCP gateway SHALL convert each Fibre Channel Name Server 1243 request to an iSNS server query. Information returned in response 1244 to the query includes the IP address, TCP port number, N_PORT ID 1245 and N_PORT world wide unique name for each remote device included 1246 in the query response. After building the table entry containing 1248 iFCP Revision 9 January 2002 1250 this information for a specific N_PORT, the iFCP layer SHALL create 1251 and add the 24-bit N_PORT alias. This alias SHALL then be returned 1252 to the local N_PORT as the Fibre Channel address of the remotely 1253 attached device. 1255 If a PLOGI is received from a remotely attached device and no 1256 translation table entry exists for that device, an entry SHALL be 1257 created using the following information: 1259 a) The world-wide unique name of the N_PORT contained in the PLOGI 1260 payload, 1262 b) The IP address and TCP port number of the remote device obtained 1263 from the TCP connection context, 1265 c) The N_PORT I/D obtained from the S_ID field in the PLOGI frame 1266 header. 1268 The N_PORT alias SHALL then be assigned and used in address 1269 translation as specified in section 5.5.2. 1271 5.5.3.1.1 Updating an Address Translation 1273 An address translation may become stale as the result of any event 1274 that invalidates or triggers a change in the fabric-assigned N_PORT 1275 network address of the remote device, such as a fabric 1276 reconfiguration or the device's removal or replacement. 1278 A collateral effect of such an event is that a Fibre Channel device 1279 that has been added or whose N_PORT I/D has changed will have no 1280 N_PORT login sessions. Consequently, frames directed to an N_PORT 1281 as the result of a stale translation table entry will be rejected 1282 or discarded by the receiving Fibre Channel device. 1284 Once the originating N_PORT learns of the reconfiguration, usually 1285 through the name server state change notification mechanism, the 1286 normal name server lookup and PLOGI mechanisms needed to 1287 reestablish the N_PORT login session will automatically purge such 1288 stale translations from the gateway. 1290 5.5.3.2 Frame Address Translation 1292 For outbound frames, the gateway-resident address translation SHALL 1293 be referenced to map the Destination N_PORT alias to the TCP 1294 connection context and N_PORT ID assigned by the remote gateway. 1295 The translation process for outbound frames is shown below. 1297 iFCP Revision 9 January 2002 1299 Raw Fibre Channel Frame 1300 +--------+-----------------------------------+ +--------------+ 1301 | | Destination N_PORT Alias |--->| Lookup TCP | 1302 +--------+-----------------------------------+ | connection | 1303 | | Source N_PORT ID | | context | 1304 +--------------------------------------------+ | and N_PORT ID| 1305 | | +------+-------+ 1306 | Control information, | | TCP 1307 | Payload and FC CRC | | conn 1308 | | | context 1309 +--------------------------------------------+ | & 1310 | N_PORT 1311 | ID 1312 | 1313 After Address Translation and Encapsulation | 1314 +--------------------------------------------+ | 1315 | FC Encapsulation Header | | 1316 +--------------------------------------------+ | 1317 | SOF Delimiter Word | | 1318 +============================================+ | 1319 | | Destination N_PORT ID |<----------+ 1320 +--------+-----------------------------------+ 1321 | | Source N_PORT ID | 1322 +--------+-----------------------------------+ 1323 | | 1324 | Control information, Payload | 1325 | and FC CRC | 1326 +============================================+ 1327 | EOF Delimiter Word | 1328 +--------------------------------------------+ 1329 Figure 9 -- Outbound Frame Address Translation 1331 For inbound frames, a translation SHALL be performed to regenerate 1332 the N_PORT alias from the TCP connection context and N_PORT ID 1333 contained in Source N_PORT I/D field of theencapsulated FC frame. 1334 The translation process for inbound frames is shown below. 1336 iFCP Revision 9 January 2002 1338 Network Format of Inbound Frame 1339 +--------------------------------------------+ TCP 1340 | FC Encapsulation Header | Connection 1341 +--------------------------------------------+ Context 1342 | SOF Delimiter Word | | 1343 +============================================+ V 1344 | | Destination N_PORT ID | +---+----+ 1345 +--------+-----------------------------------+ | Lookup | 1346 | | Source N_PORT ID |---->| Source | 1347 +--------+-----------------------------------+ | N_PORT | 1348 | | | Alias | 1349 | Control information, Payload | +----+---+ 1350 | and FC CRC | | Source 1351 +============================================+ | N_PORT 1352 | EOF Delimiter Word | | Alias 1353 +--------------------------------------------+ | 1354 | 1355 | 1356 Frame after Address Translation and De-encapsulation | 1357 +--------+-----------------------------------+ | 1358 | | Destination N_PORT ID | | 1359 +--------+-----------------------------------+ | 1360 | | Source N_PORT Alias |<---------+ 1361 +--------+-----------------------------------+ 1362 | | 1363 | Control information, Payload, | 1364 | and FC CRC | 1365 +--------------------------------------------+ 1366 Figure 10 -- Inbound Frame Address Translation 1368 In both cases, the gateway MUST recalculate the FC CRC after 1369 altering the frame contents. 1371 5.5.3.3 Incompatibility with Address Transparent Mode 1373 iFCP gateways in address translation mode SHALL NOT originate or 1374 accept frames that have the TRN bit set to one in the iFCP flags 1375 field of the encapsulation header. The iFCP gateway SHALL 1376 immediately abort all iFCP sessions with the iFCP gateway from 1377 which it receives such frames as described in section 6.2.3.2. 1379 6. iFCP Protocol 1381 6.1 Overview 1383 6.1.1 iFCP Transport Services 1385 The main function of the iFCP protocol layer is to transport Fibre 1386 Channel frame images between locally and remotely attached N_PORTs. 1388 When transporting frames to a remote N_PORT, the iFCP layer 1389 encapsulates and routes the Fibre Channel frames comprising each 1391 iFCP Revision 9 January 2002 1393 Fibre Channel Information Unit via a predetermined TCP connection 1394 for transport across the IP network. 1396 When receiving Fibre Channel frame images from the IP network, the 1397 iFCP layer de-encapsulates and delivers each frame to the 1398 appropriate N_PORT. 1400 The iFCP layer processes the following types of traffic: 1402 a) FC-4 frame images associated with a Fibre Channel application 1403 protocol. 1405 b) FC-2 frames comprising Fibre Channel link service requests and 1406 responses 1408 c) Fibre Channel broadcast frames 1410 d) iFCP control messages required to setup, manage or terminate an 1411 iFCP session. 1413 For FC-4 N_PORT traffic and most FC-2 messages the iFCP layer never 1414 interprets the contents of the frame payload. 1416 iFCP does interpret and process iFCP control messages and certain 1417 link service messages as described in section 6.1.2 1419 6.1.2 iFCP Support for Link Services 1421 iFCP must intervene in the processing of those Fibre Channel link 1422 service messages which contain N_PORT addresses in the message 1423 payload or require other special handling, such as an N_PORT login 1424 request (PLOGI). 1426 In the former case, an iFCP gateway operating in address 1427 translation mode MUST supplement the payload with additional 1428 information that enables the receiving gateway to convert such 1429 embedded N_PORT addresses to its frame of reference. 1431 For out-bound Fibre Channel frames comprising such a link service, 1432 the iFCP layer creates the supplemental information based on frame 1433 content, modifies the frame payload, then transmits the resulting 1434 Fibre Channel frame with supplemental data through the appropriate 1435 TCP connection. 1437 For incoming iFCP frames containing supplemented Fibre Channel link 1438 service frames, iFCP interprets the frame, including any 1439 supplemental information, modifies the frame content, and forwards 1440 the resulting frame to the destination N_PORT for further 1441 processing. 1443 Section 8.1 describes the processing of these link service messages 1444 in detail. 1446 iFCP Revision 9 January 2002 1448 6.2 TCP Stream Transport of iFCP Frames 1450 6.2.1 iFCP Session Model 1452 An iFCP session consists of the pair of N_PORTs comprising the 1453 session endpoints joined by a single TCP/IP connection. 1455 An N_PORT is identified by its network address consisting of: 1457 a) The N_PORT I/D assigned by the gateway to which the N_PORT is 1458 locally attached and 1460 b) The iFCP Portal address, consisting of its IP address and TCP 1461 port number. 1463 Since only one iFCP session may exist between a pair of N_PORTs, 1464 the iFCP session is uniquely identified by the network addresses of 1465 the session end points. 1467 TCP connections that may be used for iFCP sessions between pairs of 1468 iFCP portals are either "bound" or "unbound". An unbound 1469 connection is a TCP connection that is not actively supporting an 1470 iFCP session. A gateway implementation MAY establish a pool of 1471 unbound connections to reduce the session setup time. Such pre- 1472 existing TCP connections between iFCP Portals remain unbound and 1473 uncommitted until allocated to an iFCP session through a CBIND 1474 message (see section 7.1). 1476 When the iFCP layer detects a Port Login (PLOGI) message creating 1477 an iFCP session between a pair of N_PORTs, it may select an 1478 existing unbound TCP connection or establish a new TCP connection, 1479 and send the CBIND message down that TCP connection. This 1480 allocates the TCP connection to that PLOGI login session. 1482 6.2.2 iFCP Session Management 1484 This section describes the protocols for establishing and 1485 terminating an N_PORT login session. 1487 6.2.2.1 Creating an iFCP Session 1489 An iFCP session may be in one of the following states: 1491 a) OPEN -- The session state in which Fibre Channel frame images 1492 may be sent and received. 1494 b) OPEN PENDING -- The session state after a gateway has issued a 1495 CBIND request but no response has yet been received. No Fibre 1496 Channel frames may be sent. 1498 iFCP Revision 9 January 2002 1500 The gateway SHALL initiate the creation of an iFCP session in 1501 response to a PLOGI ELS directed to a remote N_PORT from a locally 1502 attached N_PORT as described in the following steps. 1504 a) If no iFCP session exists, allocate a TCP connection to the 1505 gateway to which the remote N_PORT is locally attached. An 1506 implementation may use an existing connection in the Unbound 1507 state or a new connection may be created and placed in the 1508 Unbound state. The network address of the remote gateway is 1509 obtained from the address translation table created as described 1510 in section 5.5.3 1512 b) If a connection cannot be allocated or created due to limited 1513 resources, the gateway SHALL terminate the PLOGI with an LS_RJT 1514 response. The Reason Code field in the LS_RJT message shall be 1515 set to 0x09 (Unable to Perform Command Request) and the Reason 1516 Explanation SHALL be set to 0x29 (Insufficient Resources to 1517 Support Login). 1519 c) If an iFCP session in the OPEN state already exists to the 1520 remote N_PORT, the gateway SHALL forward the PLOGI ELS using the 1521 existing session. 1523 d) If the iFCP session does not exist, the gateway SHALL issue a 1524 CBIND session control message (see section 7.1) and place the 1525 session in the OPEN PENDING state. 1527 e) If a CBIND response is returned with one of the following 1528 statuses, the PLOGI shall be terminated with an LS_RJT message. 1529 Depending on the CBIND failure status, the Reason Code and 1530 Reason Explanation SHALL be set to the following values 1531 specified in [FC-FS]. 1533 iFCP Revision 9 January 2002 1535 CBIND Failure LS_RJT Reason LS_RJT Reason Code 1536 Status Code Explanation 1537 ------------- ------------- ------------------ 1539 Unspecified Unable to Perform No additional 1540 Reason (16) Command Request explanation (0x00) 1541 (0x09) 1543 No Such Device Unable to Perform Invalid N_PORT Name 1544 (17) Command Request (0x0D). 1545 (0x09) 1547 Lack of Unable to Perform Insufficient 1548 Resources (19) Command Request Resources to Support 1549 (0x09). Login (0x29). 1551 Incompatible Unable to Perform No additional 1552 address Command Request Explanation (0x00) 1553 translation mode (0x09) 1554 (20) 1556 Incorrect iFCP Unable to Perform No additional 1557 protocol version Command Request explanation (0x00) 1558 number (21) (0x09) 1560 f) A CBIND response with a CBIND STATUS of "N_PORT session already 1561 exists" indicates that the remote gateway has concurrently 1562 initiated a CBIND request to create an iFCP session between the 1563 same pair of N_PORTs. The receiving gateway SHALL terminate this 1564 attempt, return the connection to the Unbound state and prepare 1565 to respond to an incoming CBIND request as described below. 1567 The gateway receiving a CBIND request SHALL respond as follows: 1569 a) If the receiver has a duplicate iFCP session in the OPEN PENDING 1570 state, then the receiving gateway SHALL compare the Source Port 1571 Name in the incoming CBIND payload with the Destination Port 1572 Name. 1574 b) If the Source Port Name is greater, the receiver SHALL issue a 1575 CBIND response of "Success" and SHALL place the session in the 1576 OPEN state. 1578 c) If the Source Port Name is less, the receiver shall issue a 1579 CBIND RESPONSE of Failed - N_PORT session already exists. The 1580 state of the receiver-initiated iFCP session SHALL BE unchanged. 1582 d) If there is no duplicate iFCP session, the receiving gateway 1583 SHALL issue a CBIND response. If a status of Success is 1584 returned, the receiving gateway SHALL create the iFCP session 1585 and place it in the OPEN state. 1587 iFCP Revision 9 January 2002 1589 6.2.2.2 Monitoring iFCP Connectivity 1591 During extended periods of inactivity, an iFCP session may be 1592 terminated due to a hardware failure within the gateway or through 1593 loss of TCP/IP connectivity. The latter may occur when the session 1594 traverses a stateful intermediate device, such as a NAPT box or 1595 firewall, that detects and purges connections it believes to be 1596 idle. 1598 To test session liveness, expedite the detection of connectivity 1599 failures, and avoid spontaneous connection termination, an iFCP 1600 gateway may maintain a low level of session activity and monitor 1601 the session by requesting that the remote gateway periodically 1602 transmit the LTEST message described in section 7.3. All iFCP 1603 gateways SHALL support liveness testing as described in this 1604 specification. 1606 A gateway requests the LTEST heartbeat by specifying a non-zero 1607 value for the LIVENESS TEST INTERVAL in the CBIND request or 1608 response message as described in section 7.1. If both gateways 1609 wish to monitor liveness, each must set the LIVENESS TEST INTERVAL 1610 in the CBIND request or response. 1612 Upon receiving such a request, the gateway providing the 1613 connectivity probe SHALL transmit LTEST messages at the specified 1614 interval. The first message SHALL be sent as soon as the iFCP 1615 session enters the OPEN state. LTEST messages SHALL NOT be sent 1616 when the iFCP session is not in the OPEN state. 1618 An iFCP session SHALL be aborted as described in section 6.2.3.2 1619 if: 1621 a) The contents of the LTEST message are incorrect 1623 b) An LTEST message is not received within twice the specified 1624 interval or the iFCP session has been quiescent for longer than 1625 twice the specified interval. 1627 The gateway to receive the LTEST message SHALL measure the 1628 interval for the first expected LTEST message from when the 1629 session is placed in the OPEN state. Thereafter, the interval 1630 SHALL be measured relative to the last LTEST message received. 1632 To maximize liveness test coverage, LTEST messages SHOULD flow 1633 through all the gateway components used to enter and retrieve Fibre 1634 Channel frames from the IP network. 1636 In addition to monitoring a session, information in the LTEST 1637 message encapsulation header may also be used to compute an 1638 estimate of network propagation delay as described in section 1639 9.2.1. The propagation delay limit SHALL NOT be enforced however. 1641 iFCP Revision 9 January 2002 1643 6.2.2.3 Use of TCP Features and Settings 1645 This section describes ground rules for the use of TCP features in 1646 an iFCP session. The core TCP protocol is defined in [RFC793]. 1647 TCP implementation requirements and guidelines are specified in 1648 [RFC1122]. 1650 +-----------+------------+--------------+------------+------------+ 1651 | Feature | Applicable | RFC | Peer-wise | Requirement| 1652 | | RFCs | Status | agreement | Level | 1653 | | | | required? | | 1654 +===========+============+==============+============+============+ 1655 | Keep Alive| [RFC1122] | None | No | Should not | 1656 | |(discussion)| | | use | 1657 +-----------+------------+--------------+------------+------------+ 1658 | Tiny | [RFC896] | Standard | No | Should not | 1659 | Segment | | | | use | 1660 | Avoidance | | | | | 1661 | (Nagle) | | | | | 1662 +-----------+------------+--------------+------------+------------+ 1663 | Window | [RFC1323] | Proposed | No | Should use | 1664 | Scale | | Standard | | | 1665 +-----------+------------+--------------+------------+------------+ 1666 | Wrapped | [RFC1323] | Proposed | No | Should use | 1667 | Sequence | | Standard | | | 1668 | Protection| | | | | 1669 | (PAWS) | | | | | 1670 +-----------+------------+--------------+------------+------------+ 1671 Table 1 -- Usage of Optional TCP Features 1673 The following sections describe these options in greater detail. 1675 6.2.2.3.1 Keep Alive 1677 Keep Alive speeds the detection and cleanup of dysfunctional TCP 1678 connections by sending traffic when a connection would otherwise be 1679 idle. The issues are discussed in [RFC1122]. 1681 In order to test the device more comprehensively, Fibre Channel 1682 applications, such as storage, may implement an equivalent keep 1683 alive function at the FC-4 level. For that reason and the 1684 considerations described in [RFC1122], keep alive at the transport 1685 layer should not be implemented. 1687 6.2.2.3.2 'Tiny' Segment Avoidance (Nagle) 1689 The Nagle algorithm described in [RFC896] is designed to avoid the 1690 overhead of small segments by delaying transmission in order to 1691 agglomerate transfer requests into a large segment. In iFCP, such 1692 small transfers often contain I/O requests. Hence, the 1693 transmission delay of the Nagle algorithm may decrease I/O 1694 throughput. The Nagle algorithm should therefore not be used. 1696 iFCP Revision 9 January 2002 1698 6.2.2.3.3 Window Scale 1700 Window scaling, as specified in [RFC1323], allows full utilization 1701 of links with large bandwidth - delay products and should be 1702 supported by an iFCP implementation. 1704 6.2.2.3.4 Wrapped Sequence Protection (PAWS) 1706 TCP segments are identified with 32-bit sequence numbers. In 1707 networks with large bandwidth - delay products, it is possible for 1708 more than one TCP segment with the same sequence number to be in 1709 flight. In iFCP, receipt of such a sequence out of order may cause 1710 out-of-order frame delivery or data corruption. Consequently, this 1711 feature SHOULD be supported as described in [RFC1323]. 1713 6.2.3 Terminating an N_PORT Login Session 1715 An N_PORT login session SHALL be terminated or aborted in response 1716 to one of the following events: 1718 a) An LS_RJT response is returned to the gateway that issued the 1719 PLOGI ELS. The gateway SHALL forward the LS_RJT to the local 1720 N_PORT and complete the session as described in section 1721 6.2.3.1. 1723 b) An ACC received from a remote device in response to a LOGO. The 1724 gateway SHALL forward the ACC to the local N_PORT and complete 1725 the session as described in section 6.2.3.1. 1727 c) For an FC frame received from the IP network, a gateway detects 1728 a CRC error in the encapsulation header. The gateway shall 1729 abort the session as described in section 6.2.3.2. 1731 d) The TCP connection associated with the login session fails for 1732 any reason. The gateway detecting the failed connection shall 1733 abort the session as described in section 6.2.3.2. 1735 The disposition of the associated TCP connection is described in 1736 sections 6.2.3.1 and 6.2.3.2 1738 6.2.3.1 N_PORT Login Session Completion 1740 An N_PORT login session is completed in response to a rejected 1741 PLOGI request as described in section 6.2.3 or a successful LOGO 1742 ELS. 1744 The gateway receiving one of the above responses shall issue an 1745 Unbind session control ELS as described in section 7.2. 1747 In response to the Unbind message, either gateway may choose to 1748 close the TCP connection or return it to a pool of unbound 1749 connections. 1751 iFCP Revision 9 January 2002 1753 6.2.3.2 Aborting an N_PORT Login Session 1755 An N_PORT login session SHALL be aborted if the TCP connection is 1756 spontaneously terminated or whenever one of the following occurs: 1758 a) An encapsulation error is detected as described in section 1759 6.4.3. 1761 b) The gateway receives an encapsulated frame from a gateway 1762 operating in an incompatible address translation mode as 1763 specified in section 5.5.3.3 or 5.5.1.2. 1765 In any event, the TCP connection SHOULD be terminated with a 1766 connection reset (RST). If the local N_PORT has logged in to the 1767 remote N_PORT, the gateway SHALL send a LOGO to the local N_PORT. 1769 6.3 IANA Considerations 1771 The IANA-assigned port for iFCP traffic is port number 3420. 1773 An iFCP Portal may initiate a connection using any TCP port number 1774 consistent with its implementation of the TCP/IP stack, provided 1775 each port number is unique. To prevent the receipt of stale data 1776 associated with a previous connection using a given port number, 1777 the provisions of [RFC1323], Appendix B SHOULD be observed. 1779 6.4 Encapsulation of Fibre Channel Frames 1781 This section describes the iFCP encapsulation of Fibre Channel 1782 frames. The encapsulation is based on the common encapsulation 1783 format defined in [ENCAP]. 1785 The format of an encapsulated frame is shown below: 1787 +--------------------+ 1788 | Header | 1789 +--------------------+-----+ 1790 | SOF | f | 1791 +--------------------+ F r | 1792 | FC frame content | C a | 1793 +--------------------+ m | 1794 | EOF | e | 1795 +--------------------+-----+ 1796 Figure 11 -- Encapsulation Format 1798 The encapsulation consists of a 7-word header, an SOF delimiter 1799 word, the FC frame (including the Fibre Channel CRC), and an EOF 1800 delimiter word. The header and delimiter formats are described in 1801 the following sections. When operating in Address Translation mode, 1802 (see section 5.5.2) the iFCP gateway must recalculate the Fibre 1803 Channel CRC. 1805 iFCP Revision 9 January 2002 1807 6.4.1 Encapsulation Header Format 1809 W|------------------------------Bit------------------------------| 1810 o| | 1811 r|3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 | 1812 d|1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0| 1813 +---------------+---------------+---------------+---------------+ 1814 0| Protocol# | Version | -Protocol# | -Version | 1815 +---------------+---------------+---------------+---------------+ 1816 1| Reserved (must be zero) | 1817 +---------------+---------------+---------------+---------------+ 1818 2| LS_COMMAND | iFCP Flags | SOF | EOF | 1819 +-----------+---+---------------+-----------+---+---------------+ 1820 3| Flags | Frame Length | -Flags | -Frame Length | 1821 +-----------+-------------------+-----------+-------------------+ 1822 4| Time Stamp [integer] | 1823 +---------------------------------------------------------------+ 1824 5| Time Stamp [fraction] | 1825 +---------------------------------------------------------------+ 1826 6| CRC | 1827 +---------------------------------------------------------------+ 1829 Common Encapsulation Fields: 1831 iFCP Revision 9 January 2002 1833 Protocol# IANA-assigned protocol number 1834 identifying the protocol using the 1835 encapsulation. For iFCP the value is 1836 (/TBD/). 1838 Version Encapsulation version 1840 -Protocol# Ones complement of the protocol# 1842 -Version Ones complement of the version 1844 Flags Encapsulation flags (see 6.4.1.1) 1846 Frame Length Contains the length of the entire FC 1847 Encapsulated frame including the FC 1848 Encapsulation Header and the FC frame 1849 (including SOF and EOF words) in units 1850 of 32-bit words. 1852 -Flags Ones-complement of the Flags field. 1854 -Frame Length Ones-complement of the Frame Length 1855 field. 1857 Time Stamp [integer] Integer component of the frame time 1858 stamp in SNTP format [RFC2030]. 1860 Time Stamp Fractional component of the time stamp 1861 [fraction] in SNTP format [RFC2030]. 1863 CRC Header CRC. MUST be valid for iFCP. 1865 The time stamp fields are used to enforce the limit on the 1866 lifetime of a Fibre Channel frame as described in section 1867 9.2.1. 1869 iFCP-specific fields: 1871 iFCP Revision 9 January 2002 1873 LS_COMMAND For a special link service ACC 1874 response to be processed by iFCP, the 1875 LS_COMMAND field SHALL contain bits 31 1876 through 24 of the LS_COMMAND to which 1877 the ACC applies. Otherwise the 1878 LS_COMMAND field shall be set to zero. 1880 iFCP Flags iFCP-specific flags (see below) 1882 SOF Copy of the SOF delimiter encoding 1883 (see section 6.4.2) 1885 EOF Copy of the EOF delimiter encoding 1886 (see section 6.4.2) 1888 The iFCP flags word has the following format: 1890 |------------------------Bit----------------------------| 1891 | | 1892 | 23 22 21 20 19 18 17 16 | 1893 +------+------+------+------+------+------+------+------+ 1894 | Reserved | SES | TRN | SPC | 1895 +------+------+------+------+------+------+------+------+ 1896 Figure 12 -- iFCP Flags Word 1898 iFCP Flags: 1900 SES 1 = Session control frame (TRN and SPC MUST be 1901 0) 1903 TRN 1 = Address transparent mode enabled 1905 0 = Address translation mode enabled 1907 SPC 1 = Frame is part of a link service message 1908 requiring special processing by iFCP prior 1909 to forwarding to the destination N_PORT. 1911 6.4.1.1 Common Encapsulation Flags 1913 The iFCP usage of the common encapsulation flags is shown below: 1915 iFCP Revision 9 January 2002 1917 |------------------------Bit--------------------------| 1918 | | 1919 | 31 30 29 28 27 26 | 1920 +--------------------------------------------+--------+ 1921 | Reserved | CRCV | 1922 +--------------------------------------------+--------+ 1924 For iFCP, the CRC field MUST be valid and CRCV MUST be set to one. 1926 6.4.2 SOF and EOF Delimiter Fields 1928 The format of the delimiter fields is shown below. 1930 W|------------------------------Bit------------------------------| 1931 o| | 1932 r|3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 | 1933 d|1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0| 1934 +---------------+---------------+-------------------------------+ 1935 0| SOF | SOF | -SOF | -SOF | 1936 +---------------+---------------+-------------------------------+ 1937 1| | 1938 +----- FC frame content -----+ 1939 | | 1940 +---------------+---------------+-------------------------------+ 1941 n| EOF | EOF | -EOF | -EOF | 1942 +---------------+---------------+-------------------------------+ 1943 Figure 13 -- FC Frame Encapsulation Format 1945 SOF (bits 31-24 and bits 23-16 in word 0): iFCP uses the 1946 following subset of the SOF fields described in [ENCAP]. 1948 +-------+----------+ 1949 | FC | | 1950 | SOF | SOF Code | 1951 +-------+----------+ 1952 | SOFi2 | 0x2D | 1953 | SOFn2 | 0x35 | 1954 | SOFi3 | 0x2E | 1955 | SOFn3 | 0x36 | 1956 +-------+----------+ 1957 Table 2-- Translation of FC SOF Values to SOF Field Contents 1959 -SOF (bits 15-8 and 7-0 in word 0): The -SOF fields contain the 1960 ones complement of the value in the SOF fields. 1962 EOF (bits 31-24 and 23-16 in word n): iFCP uses the following 1963 subset of EOF fields specified in [ENCAP]. 1965 iFCP Revision 9 January 2002 1967 +-------+----------+ 1968 | FC | | 1969 | EOF | EOF Code | 1970 +-------+----------+ 1971 | EOFn | 0x41 | 1972 | EOFt | 0x42 | 1973 +-------+----------+ 1974 Table 3 -- Translation of FC EOF Values to EOF Field Contents 1976 -EOF (bits 15-8 and 7-0 in word n): The -EOF fields contain the 1977 one's complement of the value in the EOF fields. 1979 iFCP implementations SHALL place a copy of the SOF and EOF 1980 delimiter codes in the appropriate header fields. 1982 6.4.3 Frame Encapsulation 1984 A Fibre Channel Frame to be encapsulated MUST first be validated as 1985 described in [FC-FS]. Any frames received from a locally attached 1986 Fibre Channel device that do not pass the validity tests in [FC-FS] 1987 SHALL be discarded by the gateway. 1989 Frames types submitted for encapsulation and forwarding on the IP 1990 network SHALL have one of the SOF delimiters in Table 2 and an EOF 1991 delimiter from Table 3. Other valid frame types MUST be processed 1992 internally by the gateway as specified in the appropriate Fibre 1993 Channel specification. 1995 Prior to submitting a frame for encapsulation, a gateway in address 1996 translation mode SHALL replace the D_ID address, and, if processing 1997 a special link service message requiring the inclusion of 1998 supplemental data, SHALL format the frame payload and add the 1999 supplemental information as specified in section 8.1. The gateway 2000 SHALL then calculate a new FC CRC on the reformatted frame. 2002 A gateway in address transparent mode MAY encapsulate and transmit 2003 the frame image without recalculating the FC CRC. 2005 The frame originator MUST then create and fill in the header and 2006 the SOF and EOF delimiter words as specified above. 2008 6.4.4 Frame De-encapsulation 2010 The receiving gateway SHALL perform de-encapsulation as follows: 2012 Upon receiving the encapsulated frame, the gateway SHALL check the 2013 header CRC. If the header CRC is invalid, the gateway SHALL 2014 terminate the N_PORT login session as described in section 6.2.3.2. 2016 After validating the header CRC, the receiving gateway SHALL verify 2017 the frame propagation delay as described in section 9.2.1. If the 2018 propagation delay is too long, the frame SHALL be discarded. 2020 iFCP Revision 9 January 2002 2022 Otherwise, the gateway SHALL check the SOF and EOF in the 2023 encapsulation header. A frame SHALL be discarded if it has an SOF 2024 code that is not in Table 2 or an EOF code that is not in Table 3. 2026 The gateway shall then de-encapsulate the frame. If operating in 2027 address translation mode, the gateway SHALL: 2029 a) Check the FC CRC and discard the frame if the CRC is invalid. 2031 b) Replace the S_ID with the N_PORT alias of the frame originator 2033 c) If processing a special link service message, replace the frame 2034 with a copy whose payload has been modified as specified in 2035 section 8.1. 2037 The de-encapsulated frame SHALL then be delivered to the N_PORT 2038 specified in the D_ID field. If the frame contents have been 2039 modified by the receiving gateway, a new FC CRC SHALL be 2040 calculated. 2042 7. TCP Session Control Messages 2044 TCP session control messages are used to create and manage an iFCP 2045 session as described in section 6.2.2. They are passed between peer 2046 iFCP Portals and are only processed within the iFCP layer. 2048 The message format is based on the Fibre Channel extended link 2049 service message template shown below. 2051 iFCP Revision 9 January 2002 2053 Word 2054 3124 23<---------------Bits------------------------->0 2055 +------------+------------------------------------------------+ 2056 0| R_CTL | D_ID [0x00 00 00] | 2057 |[Req = 0x22]| [Destination of extended link Service request] | 2058 |[Rep = 0x23]| | 2059 +------------+------------------------------------------------+ 2060 1| CS_CTL | S_ID [0x00 00 00] | 2061 | [0x0] | [Source of extended link service request] | 2062 +------------+------------------------------------------------+ 2063 2|TYPE [0x1] | F_CTL [0] | 2064 +------------+------------------+-----------------------------+ 2065 3|SEQ_ID | DF_CTL [0x00] | SEQ_CNT [0x00] | 2066 |[0x0] | | | 2067 +------------+------------------+-----------------------------+ 2068 4| OX_ID [0x0000] | RX_ID_[0x0000] | 2069 +-------------------------------+-----------------------------+ 2070 5| Parameter | 2071 | [ 00 00 00 00 ] | 2072 +-------------------------------------------------------------+ 2073 6| LS_COMMAND | 2074 | [Session Control Command Code] | 2075 +-------------------------------------------------------------+ 2076 7| | 2077 .| Additional Session Control Parameters | 2078 .| ( if any ) | 2079 n| | 2080 +=============================================================+ 2081 n| Fibre Channel CRC | 2082 +| | 2083 1+=============================================================+ 2084 Figure 14 -- Format of Session Control Message 2086 The LS_COMMAND value for the response remains the same as that used 2087 for the request. 2089 The session control ELS frame is terminated with a Fibre Channel 2090 CRC. The frame SHALL be encapsulated and de-encapsulated according 2091 to the rules specified in section 6.4. 2093 The encapsulation header for the link Service frame carrying a TCP 2094 ELS message SHALL be set as follows: 2096 Encapsulation Header Fields: 2098 iFCP Revision 9 January 2002 2100 LS_COMMAND 0 2102 iFCP Flags SES = 1 2104 TRN = 0 2106 INT = 0 2108 SOF code SOFi3 encoding (0x2E) 2110 EOF code EOFt encoding (0x42) 2112 The encapsulation time stamp words SHALL be set as described for 2113 each message type. 2115 The SOF and EOF delimiter words SHALL be set based on the SOF and 2116 EOF codes specified above. 2118 The following lists the session control messages and their 2119 corresponding LS_COMMAND values. 2121 Request LS_COMMAND Short Name iFCP Support 2122 ------- ---------- ---------- ----------- 2123 Connection Bind 0xE0 CBIND REQUIRED 2124 Unbind Connection 0xE4 UNBIND REQUIRED 2125 Test Connection Liveness 0xE5 LTEST Required 2127 7.1 Connection Bind (CBIND) 2129 As described in section 6.2.2.1, the CBIND message and response are 2130 used to bind an N_PORT login session to a specific TCP connection 2131 and establish an iFCP session. In the CBIND request message, the 2132 source and destination N_Ports are identified by the N_PORT network 2133 address (iFCP portal address and N_PORT ID). The time stamp words 2134 in the encapsulation header shall be set to zero in the request and 2135 response message frames. 2137 The following shows the format of the CBIND request. 2139 iFCP Revision 9 January 2002 2141 +------+------------+------------+-----------+----------+ 2142 | Word | Byte 0 | Byte 1 | Byte 2 | Byte 3 | 2143 +------+------------+------------+-----------+----------+ 2144 | 0 | Cmd = 0xE0 | 0x00 | 0x00 | 0x00 | 2145 +------+------------+------------+-----------+----------+ 2146 | 1 | LIVENESS TEST INTERVAL | Addr Mode | iFCP Ver | 2147 | | (Seconds) | | | 2148 +------+-------------------------+-----------+----------+ 2149 | 2 | USER INFO | 2150 +------+------------+------------+-----------+----------+ 2151 | 3 | | 2152 +------+ SOURCE N_PORT NAME | 2153 | 4 | | 2154 +------+------------------------------------------------+ 2155 | 5 | | 2156 +------+ DESTINATION N_PORT NAME | 2157 | 6 | | 2158 +------+------------------------------------------------+ 2160 Addr Mode: The addressing mode of the originating 2161 gateway. 0 = Address Translation mode, 1 = 2162 Address Transparent mode. 2164 iFCP Ver: iFCP version number. SHALL be set to 1. 2166 LIVENESS TEST If non-zero, requests that the receiving 2167 INTERVAL: gateway transmit an LTEST message at the 2168 specified interval in seconds. 2170 USER INFO: Contains any data desired by the requestor. 2171 This information MUST be echoed by the 2172 recipient in the CBIND response message. 2174 SOURCE N_PORT NAME: The World Wide Port Name (WWPN) of the 2175 N_PORT locally attached to the gateway 2176 originating the CBIND request. 2178 DESTINATION N_PORT The World Wide Port Name (WWPN) of the 2179 NAME: N_PORT locally attached to the gateway 2180 receiving the CBIND request. 2182 The following shows the format of the CBIND response. 2184 iFCP Revision 9 January 2002 2186 +------+------------+------------+-----------+----------+ 2187 | Word | Byte 0 | Byte 1 | Byte 2 | Byte 3 | 2188 +------+------------+------------+-----------+----------+ 2189 | 0 | Cmd = 0xE0 | 0x00 | 0x00 | 0x00 | 2190 +------+------------+------------+-----------+----------+ 2191 | 1 | LIVENESS TEST INTERVAL | Addr Mode | iFCP Ver | 2192 | | (Seconds) | | | 2193 +------+-------------------------+-----------+----------+ 2194 | 2 | USER INFO | 2195 +------+------------+------------+-----------+----------+ 2196 | 3 | | 2197 +------+ SOURCE N_PORT NAME | 2198 | 4 | | 2199 +------+------------------------------------------------+ 2200 | 5 | | 2201 +------+ DESTINATION N_PORT NAME | 2202 | 6 | | 2203 +------+-------------------------+----------------------+ 2204 | 7 | Reserved | CBIND Status | 2205 +------+-------------------------+----------------------+ 2206 | 8 | Reserved | CONNECTION HANDLE | 2207 +------+-------------------------+----------------------+ 2208 Total Length = 32 2210 iFCP Revision 9 January 2002 2212 Addr Mode: The address translation mode of the 2213 responding gateway. 0 = Address 2214 Translation mode, 1 = Address Transparent 2215 mode. 2217 iFCP Ver: iFCP version number. Shall be set to 1. 2219 LIVENESS TEST If non-zero, requests that the gateway 2220 INTERVAL: receiving the CBIND RESPONSE transmit an 2221 LTEST message at the specified interval in 2222 seconds. 2224 USER INFO: Echoes the value received in the USER INFO 2225 field of the CBIND request message. 2227 SOURCE N_PORT NAME: Contains the World Wide Port Name (WWPN) of 2228 the N_PORT locally attached to the gateway 2229 issuing the CBIND request. 2231 DESTINATION N_PORT Contains the World Wide Port Name (WWPN) of 2232 NAME: the N_PORT locally attached to the gateway 2233 issuing the CBIND response. 2235 CBIND STATUS: Indicates success or failure of the CBIND 2236 request. CBIND values are shown below. 2238 CONNECTION HANDLE: Contains a value assigned by the gateway to 2239 identify the connection. The connection 2240 handle is required when issuing the UNBIND 2241 request. 2243 CBIND Status Description 2244 ------------ ----------- 2246 0 Successful � No other status 2247 1 � 15 Reserved 2248 16 Failed � Unspecified Reason 2249 17 Failed � No such device 2250 18 Failed � N_PORT session already exists 2251 19 Failed � Lack of resources 2252 20 Failed - Incompatible address translation mode 2253 21 Failed - Incorrect protocol version number 2254 Others Reserved 2256 7.2 Unbind Connection (UNBIND) 2258 UNBIND is used to release a bound TCP connection and return it to 2259 the pool of unbound TCP connections. This message is transmitted 2260 in the connection that is to be unbound. The time stamp words in 2262 iFCP Revision 9 January 2002 2264 the encapsulation header shall be set to zero in the request and 2265 response message frames. 2267 The following is the format of the UNBIND request message. 2269 +------+------------+------------+-----------+----------+ 2270 | Word | Byte 0 | Byte 1 | Byte 2 | Byte 3 | 2271 +------+------------+------------+-----------+----------+ 2272 | 0 | Cmd = 0xE4 | 0x00 | 0x00 | 0x00 | 2273 +------+------------+------------+-----------+----------+ 2274 | 1 | USER INFO | 2275 +------+------------+------------+-----------+----------+ 2276 | 2 | Reserved | CONNECTION HANDLE | 2277 +------+------------+------------+----------------------+ 2278 | 3 | Reserved | 2279 +------+------------+------------+-----------+----------+ 2280 | 4 | Reserved | 2281 +------+------------+------------+-----------+----------+ 2283 USER INFO Contains any data desired by the requestor. 2284 This information MUST be echoed by the 2285 recipient in the UNBIND response message. 2287 CONNECTION HANDLE: Contains the gateway-assigned value from 2288 the CBIND request. 2290 The following shows the format of the UNBIND response message. 2292 +------+------------+------------+-----------+----------+ 2293 | Word | Byte 0 | Byte 1 | Byte 2 | Byte 3 | 2294 +------+------------+------------+-----------+----------+ 2295 | 0 | Cmd = 0xE4 | 0x00 | 0x00 | 0x00 | 2296 +------+------------+------------+-----------+----------+ 2297 | 1 | USER INFO | 2298 +------+------------+------------+-----------+----------+ 2299 | 2 | Reserved | CONNECTION HANDLE | 2300 +------+------------+------------+-----------+----------+ 2301 | 3 | Reserved | 2302 +------+------------+------------+-----------+----------+ 2303 | 4 | Reserved | 2304 +------+------------+------------+-----------+----------+ 2305 | 5 | Reserved | UNBIND STATUS | 2306 +------+------------+------------+-----------+----------+ 2308 iFCP Revision 9 January 2002 2310 USER INFO Echoes the value received in the USER INFO 2311 field of the UNBIND request message. 2313 CONNECTION HANDLE: Echoes the CONNECTION HANDLE specified in 2314 the UNBIND request message. 2316 UNBIND STATUS: Indicates the success or failure of the 2317 UNBIND request as follows: 2319 Unbind Status Description 2320 ------------- ----------- 2322 0 Successful � No other status 2323 1 � 15 Reserved 2324 16 Failed � Unspecified Reason 2325 18 Failed � Connection ID Invalid 2326 Others Reserved 2328 7.3 LTEST -- Test Connection Liveness 2330 The LTEST message is sent at the interval specified in the CBIND 2331 request or response payload. The LTEST encapsulation time stamp 2332 SHALL be set as described in section 9.2.1 and may be used by the 2333 receiver to compute an estimate of propagation delay. However, the 2334 propagation delay limit SHALL NOT be enforced. 2336 iFCP Revision 9 January 2002 2338 +------+------------+------------+-----------+----------+ 2339 | Word | Byte 0 | Byte 1 | Byte 2 | Byte 3 | 2340 +------+------------+------------+-----------+----------+ 2341 | 0 | Cmd = 0xE5 | 0x00 | 0x00 | 0x00 | 2342 +------+------------+------------+-----------+----------+ 2343 | 1 | LIVENESS TEST INTERVAL | Reserved | 2344 | | (Seconds) | | 2345 +------+-------------------------+----------------------+ 2346 | 2 | COUNT | 2347 +------+------------+------------+-----------+----------+ 2348 | 3 | | 2349 +------+ SOURCE N_PORT NAME | 2350 | 4 | | 2351 +------+------------------------------------------------+ 2352 | 5 | | 2353 +------+ DESTINATION N_PORT NAME | 2354 | 6 | | 2355 +------+------------------------------------------------+ 2357 LIVENESS TEST Copy of the LIVENESS TEST INTERVAL 2358 INTERVAL: specified in the CBIND request or reply 2359 message. 2361 COUNT: Monotonically increasing value, initialized 2362 to 0 and incremented by one for each 2363 successive LTEST message. 2365 SOURCE N_PORT NAME: Contains a copy of the SOURCE N_PORT NAME 2366 specified in the CBIND request. 2368 DESTINATION N_PORT Contains a copy of the DESTINATION N_PORT 2369 NAME: NAME specified in the CBIND request. 2371 8. Fibre Channel Link Services 2373 Link services provide a set of Fibre Channel functions that allow a 2374 port to send control information or request another port to perform 2375 a specific control function. 2377 There are three types of link services: 2379 a) Basic 2381 b) Extended 2383 c) ULP-specific (FC-4) 2385 Each link service message (request and reply) is carried by a Fibre 2386 Channel sequence, and can be segmented into multiple frames. 2388 iFCP Revision 9 January 2002 2390 The iFCP Layer is responsible for transporting link service 2391 messages across the IP fabric. This includes mapping Link Service 2392 messages appropriately from the domain of the Fibre Channel 2393 transport to that of the IP network. This process may require 2394 special processing and the inclusion of supplemental data by the 2395 iFCP layer. 2397 Each link service is processed according to one of the following 2398 rules: 2400 a) Transparent � The link service message and reply MUST be 2401 transported to the receiving N_PORT by the iFCP gateway without 2402 altering the message payload. The link service message and reply 2403 are not processed by the iFCP implementation. 2405 b) Special - Applies to a link service reply or request requiring 2406 iFCP intervention before forwarding to the destination N_PORT. 2407 Such messages may contain Fibre Channel addresses in the payload 2408 or may require other special processing. 2410 c) Rejected � When issued by a locally attached N_PORT, the 2411 specified link service request MUST be rejected by the iFCP 2412 implementation. The gateway SHALL respond to a rejected link 2413 service message by returning an LS_RJT response with a Reason 2414 Code of 0x0B (Command Not Supported) and a Reason Code 2415 Explanation of 0x0 (No Additional Explanation). 2417 This section describes the processing for special link services, 2418 including the manner in which supplemental data is added to the 2419 message payload. 2421 Appendix A enumerates all link services and the iFCP processing 2422 policy that applies to each. 2424 8.1 Special Link Service Messages 2426 Special link service messages require the intervention of the iFCP 2427 layer before forwarding to the destination N_PORT. Such 2428 intervention is required in order to: 2430 a) Service any link service message which requires special 2431 handling, such as a PLOGI. 2433 b) In address translation mode only, service any link service 2434 message which has an N_PORT address in the payload. 2436 Such messages are transmitted in a Fibre Channel frame having the 2437 format shown in Figure 15 for extended link services or Figure 16 2438 for FC-4 link services.: 2440 iFCP Revision 9 January 2002 2442 Word 2443 31 24 23 0 2444 +------------+------------------------------------------------+ 2445 0| R_CTL | D_ID | 2446 |[Req = 0x22]|[Destination of extended link Service request] | 2447 |[Rep = 0x23]| | 2448 +------------+------------------------------------------------+ 2449 1| CS_CTL | S_ID | 2450 | | [Source of extended link service request] | 2451 +------------+------------------------------------------------+ 2452 2| TYPE | F_CTL | 2453 | [0x01] | | 2454 +------------+------------------+-----------------------------+ 2455 3| SEQ_ID | DF_CTL | SEQ_CNT | 2456 +------------+------------------+-----------------------------+ 2457 4| OX_ID | RX_ID | 2458 +-------------------------------+-----------------------------+ 2459 5| Parameter | 2460 | [ 00 00 00 00 ] | 2461 +-------------------------------------------------------------+ 2462 6| LS_COMMAND | 2463 | [Extended Link Service Command Code] | 2464 +-------------==----------------------------------------------+ 2465 7| | 2466 .| Additional Service Request Parameters | 2467 .| ( if any ) | 2468 n| | 2469 +-------------------------------------------------------------+ 2470 Figure 15 -- Format of an Extended Link Service Frame 2472 iFCP Revision 9 January 2002 2474 Word 2475 31 24 23 0 2476 +------------+------------------------------------------------+ 2477 0| R_CTL | D_ID | 2478 |[Req = 0x32]| [Destination of FC-4 link Service request] | 2479 |[Rep = 0x33]| | 2480 +------------+------------------------------------------------+ 2481 1| CS_CTL | S_ID | 2482 | | [Source of FC-4 link service request] | 2483 +------------+------------------------------------------------+ 2484 2| TYPE | F_CTL | 2485 | (FC-4 | | 2486 | specific) | | 2487 +------------+------------------+-----------------------------+ 2488 3| SEQ_ID | DF_CTL | SEQ_CNT | 2489 +------------+------------------+-----------------------------+ 2490 4| OX_ID | RX_ID | 2491 +-------------------------------+-----------------------------+ 2492 5| Parameter | 2493 | [ 00 00 00 00 ] | 2494 +-------------------------------------------------------------+ 2495 6| LS_COMMAND | 2496 | [FC-4 Link Service Command Code] | 2497 +-------------------------------------------------------------+ 2498 7| | 2499 .| Additional Service Request Parameters | 2500 .| ( if any ) | 2501 n| | 2502 +-------------------------------------------------------------+ 2503 Figure 16 -- Format of an FC-4 Link Service Frame 2505 8.2 Link Services Requiring Payload Address Translation 2507 This section describes the handling for link service frames 2508 containing N_PORT addresses in the frame payload. Such addresses 2509 SHALL only be translated when the gateway is operating in address 2510 translation mode. When operating in address transparent mode, 2511 these addresses SHALL NOT be translated. In addition, such link 2512 service messages SHALL NOT be sent as special frames unless other 2513 processing by the iFCP layer is required. 2515 Supplemental data includes information required by the receiving 2516 gateway to convert an N_PORT address in the payload to an N_PORT 2517 address in the receiving gateway�s address space. The following 2518 rules define the manner in which such supplemental data is packaged 2519 and referenced. 2521 For an N_PORT address field, the gateway originating the frame MUST 2522 set the value in the payload to identify the address translation 2523 type as follows: 2525 iFCP Revision 9 January 2002 2527 0x00 00 01 � The gateway receiving the frame from the IP 2528 network MUST replace the contents of the field with the N_PORT 2529 alias of the frame originator. This translation type MUST be 2530 used when the address to be converted is that of the source 2531 N_PORT. 2533 0x00 00 02 � The gateway receiving the frame from the IP 2534 network MUST replace the contents of the field with the N_PORT 2535 I/D of the destination N_PORT. This translation type MUST be 2536 used when the address to be converted is that of the 2537 destination N_PORT 2539 0x00 00 03 � The gateway receiving the frame from the IP 2540 network MUST reference the specified supplemental data to set 2541 the field contents. The supplemental information is the 64-bit 2542 world wide identifier of the N_PORT as set forth in the Fibre 2543 Channel specification [FC-FS]. If not otherwise part of the 2544 link service payload, this information MUST be appended in 2545 accordance with the applicable link service description. Unless 2546 specified otherwise, this translation type SHALL NOT be used if 2547 the address to be converted corresponds to that of the frame 2548 originator or recipient. 2550 Since Fibre Channel addressing rules prohibit the assignment of 2551 fabric addresses with a domain I/D of 0, the above codes will never 2552 correspond to valid N_PORT fabric IDs. 2554 For translation type 3, the receiving gateway SHALL obtain the 2555 information needed to fill in the field in the link service frame 2556 payload by converting the specified N_PORT world-wide identifier to 2557 a gateway IP address and N_PORT ID. This information MUST be 2558 obtained through a name server query. If the N_PORT is locally 2559 attached, the gateway MUST fill in the field with the N_PORT ID. 2560 If the N_PORT is remotely attached, the gateway MUST assign and 2561 fill in the field with an N_PORT alias. If an N_PORT alias has 2562 already been assigned, it MUST be reused. 2564 In the event that the sending gateway cannot obtain the world wide 2565 identifier of an N_PORT, or a receiving gateway cannot obtain the 2566 IP address and N_PORT ID, the gateway detecting the error SHALL 2567 terminate the request with an LS_RJT message as described in [FC- 2568 FS]. The Reason Code SHALL be set to 0x07 (protocol error) and the 2569 Reason Explanation SHALL be set to 0x1F (Invalid N_PORT 2570 identifier). 2572 Supplemental data is sent with the link service request or ACC 2573 frames in one of the following ways: 2575 a) By appending the necessary data to the end of the link service 2576 frame. 2578 b) By extending the sequence with additional frames. 2580 iFCP Revision 9 January 2002 2582 In the first case, a new frame SHALL be created whose length 2583 includes the supplemental data. The procedure for extending the 2584 link service sequence with additional frames is dependent on the 2585 link service type. 2587 After applying the supplemental data, the receiving gateway SHALL 2588 forward the resulting link service frames to the destination N_PORT 2589 with the supplemental information removed. 2591 When the ACC response requires iFCP intervention, the receiving 2592 gateway MUST act as a proxy for the originator, retaining the state 2593 needed to process the response from the N_PORT to which the request 2594 was directed. 2596 8.3 Fibre Channel Link Services Processed by iFCP 2598 The following Extended and FC-4 Link Service Messages must receive 2599 special processing. 2601 Extended Link Service Messages LS_COMMAND Mnemonic 2602 ------------------------------ ---------- -------- 2603 Abort Exchange 0x06 00 00 00 ABTX 2604 Discover Address 0x52 00 00 00 ADISC 2605 Discover Address Accept 0x02 00 00 00 ADISC ACC 2606 FC Address Resolution Protocol 0x55 00 00 00 FARP-REPLY 2607 Reply 2608 FC Address Resolution Protocol 0x54 00 00 00 FARP-REQ 2609 Request 2610 Logout 0x05 00 00 00 LOGO 2611 Port Login 0x30 00 00 00 PLOGI 2612 Read Exchange Status Block 0x08 00 00 00 RES 2613 Read Exchange Status Block 0x02 00 00 00 RES ACC 2614 Accept 2615 Read Link Error Status Block 0x0F 00 00 00 RLS 2616 Read Sequence Status Block 0x09 00 00 00 RSS 2617 Reinstate Recovery Qualifier 0x12 00 00 00 RRQ 2618 Request Sequence Initiative 0x0A 00 00 00 RSI 2619 Third Party Process Logout 0x24 00 00 00 TPRLO 2620 Third Party Process Logout 0x02 00 00 00 TPRLO ACC 2621 Accept 2623 FC-4 Link Service Messages LS_COMMAND Mnemonic 2624 -------------------------- ---------- -------- 2625 FCP Read Exchange Concise 0x13 00 00 00 REC 2626 FCP Read Exchange Concise 0x02 00 00 00 REC ACC 2627 Accept 2629 Each encapsulated Fibre Channel frame that is part of a special 2630 link service MUST have the SPC bit set to one in the iFCP FLAGS 2631 field of the encapsulation header as specified in section 6.4.1. 2633 iFCP Revision 9 January 2002 2635 Supplemental data (if any) MUST be appended as described in the 2636 following section. 2638 The formats of each special link service message, including 2639 supplemental data where applicable, are shown in the following 2640 sections. Each description shows the basic format, as specified in 2641 the applicable FC standard, followed by supplemental data as shown 2642 in the example below. 2644 +------+------------+------------+-----------+----------+ 2645 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2646 +------+------------+------------+-----------+----------+ 2647 | 0 | LS_COMMAND | 2648 +------+------------+------------+-----------+----------+ 2649 | 1 | | 2650 | . | | 2651 | . | Link Service Frame Payload | 2652 | | | 2653 | n | | 2654 +======+============+============+===========+==========+ 2655 | n+1 | | 2656 | . | Supplemental Data | 2657 | . | (if any) | 2658 | n+k | | 2659 +======+================================================+ 2660 Figure 17 -- Special Link Service Frame Payload 2662 8.3.1 Special Extended Link Services 2664 The following sections define extended link services for which 2665 special processing is required. 2667 8.3.1.1 Abort Exchange (ABTX) 2669 ELS Format: 2671 +------+------------+------------+-----------+----------+ 2672 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2673 +------+------------+------------+-----------+----------+ 2674 | 0 | Cmd = 0x6 | 0x00 | 0x00 | 0x00 | 2675 +------+------------+------------+-----------+----------+ 2676 | 1 | RRQ Status | Exchange Originator S_ID | 2677 +------+------------+------------+-----------+----------+ 2678 | 2 | OX_ID of Tgt exchange | RX_ID of tgt exchange| 2679 +------+------------+------------+-----------+----------+ 2680 | 3-10 | Optional association header (32 bytes | 2681 +======+============+============+===========+==========+ 2683 Fields Requiring Translation Supplemental Data 2684 Address Translation Type (see (type 3 only) 2686 iFCP Revision 9 January 2002 2688 ------------------- section 8.2) ------------ 2689 ----------- 2691 Exchange Originator 1, 2 N/A 2692 S_ID 2694 Other Special Processing: 2696 None 2698 8.3.1.2 Discover Address (ADISC) 2700 Format of ADISC ELS: 2702 +------+------------+------------+-----------+----------+ 2703 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2704 +------+------------+------------+-----------+----------+ 2705 | 0 | Cmd = 0x52 | 0x00 | 0x00 | 0x00 | 2706 +------+------------+------------+-----------+----------+ 2707 | 1 | Reserved | Hard address of ELS Originator | 2708 +------+------------+------------+-----------+----------+ 2709 | 2-3 | Port Name of Originator | 2710 +------+------------+------------+-----------+----------+ 2711 | 4-5 | Node Name of originator | 2712 +------+------------+------------+-----------+----------+ 2713 | 6 | Rsvd | N_PORT I/D of ELS Originator | 2714 +======+============+============+===========+==========+ 2716 Fields Requiring Translation Supplemental Data 2717 Address Translation Type (see (type 3 only) 2718 ------------------- section 8.2) ------------ 2719 ------------- 2721 N_PORT I/D of ELS 1 N/A 2722 Originator 2724 Other Special Processing: 2726 The Hard Address of the ELS originator SHALL be set to 0. 2728 8.3.1.3 Discover Address Accept (ADISC ACC) 2730 Format of ADISC ACC ELS: 2732 iFCP Revision 9 January 2002 2734 +------+------------+------------+-----------+----------+ 2735 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2736 +------+------------+------------+-----------+----------+ 2737 | 0 | Cmd = 0x20 | 0x00 | 0x00 | 0x00 | 2738 +------+------------+------------+-----------+----------+ 2739 | 1 | Reserved | Hard address of ELS Originator | 2740 +------+------------+------------+-----------+----------+ 2741 | 2-3 | Port Name of Originator | 2742 +------+------------+------------+-----------+----------+ 2743 | 4-5 | Node Name of originator | 2744 +------+------------+------------+-----------+----------+ 2745 | 6 | Rsvd | N_PORT I/D of ELS Originator | 2746 +======+============+============+===========+==========+ 2748 Fields Requiring Translation Supplemental Data 2749 Address Translation Type (see (type 3 only) 2750 ------------------- section 8.2) ------------ 2751 ------------ 2753 N_PORT I/D of ELS 1 N/A 2754 Originator 2756 Other Special Processing: 2758 The Hard Address of the ELS originator SHALL be set to 0. 2760 8.3.1.4 FC Address Resolution Protocol Reply (FARP-REPLY) 2762 The FARP-REPLY ELS is used in conjunction with the FARP-REQ ELS 2763 (see section 8.3.1.5) to perform the address resolution services 2764 required by the FC-VI protocol [FC-VI] and the Fibre Channel 2765 mapping of IP and ARP specified in RFC 2625 [RFC2625]. 2767 Format of FARP-REPLY ELS: 2769 iFCP Revision 9 January 2002 2771 +------+------------+------------+-----------+----------+ 2772 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2773 +------+------------+------------+-----------+----------+ 2774 | 0 | Cmd = 0x55 | 0x00 | 0x00 | 0x00 | 2775 +------+------------+------------+-----------+----------+ 2776 | 1 | Match Addr | Requesting N_PORT Identifier | 2777 | | Code Points| | 2778 +------+------------+------------+-----------+----------+ 2779 | 2 | Responder | Responding N_PORT Identifier | 2780 | | Action | | 2781 +------+------------+------------+-----------+----------+ 2782 | 3-4 | Requesting N_PORT Port_Name | 2783 +------+------------+------------+-----------+----------+ 2784 | 5-6 | Requesting N_PORT Node_Name | 2785 +------+------------+------------+-----------+----------+ 2786 | 7-8 | Responding N_PORT Port_Name | 2787 +------+------------+------------+-----------+----------+ 2788 | 9-10 | Responding N_PORT Node_Name | 2789 +------+------------+------------+-----------+----------+ 2790 | 11-14| Requesting N_PORT IP Address | 2791 +------+------------+------------+-----------+----------+ 2792 | 15-18| Responding N_PORT IP Address | 2793 +======+============+============+===========+==========+ 2795 Fields Requiring Translation Supplemental Data 2796 Address Translation Type (see (type 3 only) 2797 ------------------- section 8.2) ----------------- 2798 ------------- 2800 Requesting N_PORT 2 N/A 2801 Identifier 2803 Responding N_PORT 1 N/A 2804 identifier 2806 Other Special Processing: 2808 None. 2810 8.3.1.5 FC Address Resolution Protocol Request (FARP-REQ) 2812 The FARP-REQ ELS is used to in conjunction with the FC-VI protocol 2813 [FC-VI] and IP to FC mapping of RFC 2625 [RFC2625] to perform IP 2814 and FC address resolution in an FC fabric. The FARP-REQ ELS is 2815 usually directed to the fabric broadcast server at well-known 2816 address 0xFF-FF-FF for retransmission to all attached N_PORTs. 2818 iFCP Revision 9 January 2002 2820 Section 10.4 describes the iFCP implementation of FC broadcast 2821 server functionality in an iFCP fabric. 2823 Format of FARP_REQ ELS: 2825 +------+------------+------------+-----------+----------+ 2826 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2827 +------+------------+------------+-----------+----------+ 2828 | 0 | Cmd = 0x54 | 0x00 | 0x00 | 0x00 | 2829 +------+------------+------------+-----------+----------+ 2830 | 1 | Match Addr | Requesting N_PORT Identifier | 2831 | | Code Points| | 2832 +------+------------+------------+-----------+----------+ 2833 | 2 | Responder | Responding N_PORT Identifier | 2834 | | Action | | 2835 +------+------------+------------+-----------+----------+ 2836 | 3-4 | Requesting N_PORT Port_Name | 2837 +------+------------+------------+-----------+----------+ 2838 | 5-6 | Requesting N_PORT Node_Name | 2839 +------+------------+------------+-----------+----------+ 2840 | 7-8 | Responding N_PORT Port_Name | 2841 +------+------------+------------+-----------+----------+ 2842 | 9-10 | Responding N_PORT Node_Name | 2843 +------+------------+------------+-----------+----------+ 2844 | 11-14| Requesting N_PORT IP Address | 2845 +------+------------+------------+-----------+----------+ 2846 | 15-18| Responding N_PORT IP Address | 2847 +======+============+============+===========+==========+ 2849 Fields Requiring Translation Supplemental Data 2850 Address Translation Type (see (type 3 only) 2851 ------------------- section 8.2) ----------------- 2852 ----------- 2854 Requesting N_PORT 3 Requesting N_PORT 2855 Identifier Port Name 2857 Responding N_PORT 3 Responding N_PORT 2858 Identifier Port Name 2860 Other Special Processing: 2862 None. 2864 8.3.1.6 Logout (LOGO) 2866 ELS Format: 2868 iFCP Revision 9 January 2002 2870 +------+------------+------------+-----------+----------+ 2871 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2872 +------+------------+------------+-----------+----------+ 2873 | 0 | Cmd = 0x5 | 0x00 | 0x00 | 0x00 | 2874 +------+------------+------------+-----------+----------+ 2875 | 1 | Rsvd | N_PORT I/D being logged out | 2876 +------+------------+------------+-----------+----------+ 2877 | 2-3 | Port name of the LOGO originator (8 bytes) | 2878 +======+============+============+===========+==========+ 2880 This ELS shall always be sent as an augmented ELS regardless of the 2881 translation mode in effect. 2883 Fields Requiring Translation Supplemental Data 2884 Address Translation Type(see (type 3 only) 2885 ------------------- section 8.2) -------------- 2886 ----------- 2888 N_PORT I/D Being 1 N/A 2889 Logged Out 2891 Other Special Processing: 2893 See section 6.2.3.1. 2895 8.3.1.7 Port Login (PLOGI) and PLOGI ACC 2897 PLOGI provides the mechanism for establishing a login session 2898 between two N_PORTs. In iFCP, a PLOGI request addressed to a 2899 remotely attached N_PORT may trigger the creation of an iFCP 2900 session, if one does not already exist. Otherwise, the PLOGI and 2901 PLOGI ACC payloads MUST be passed transparently to the destination 2902 N_PORT. 2904 The PLOGI request and ACC response carry information identifying 2905 the originating N_PORT, including specification of its capabilities 2906 and limitations. If the destination N_PORT accepts the login 2907 request, it sends an accept (an ACC frame with PLOGI payload), 2908 specifying its capabilities and limitations. This exchange 2909 establishes the operating environment for the two N_PORTs. 2911 The following figure is duplicated from [FC-FS], and shows the 2912 PLOGI message format for both request and accept (ACC) response. A 2913 port will reject a PLOGI request by transmitting an LS_RJT message, 2914 which contains no payload. 2916 iFCP Revision 9 January 2002 2918 Byte 2919 Offset 2920 +----------------------------------+ 2921 0 | LS_COMMAND | 4 Bytes 2922 +----------------------------------+ 2923 4 | COMMON SERVICE PARAMETERS | 16 Bytes 2924 +----------------------------------+ 2925 20 | PORT NAME | 8 Bytes 2926 +----------------------------------+ 2927 28 | NODE NAME | 8 Bytes 2928 +----------------------------------+ 2929 36 | CLASS 1 SERVICE PARAMETERS | 16 Bytes 2930 +----------------------------------+ 2931 52 | CLASS 2 SERVICE PARAMETERS | 16 Bytes 2932 +----------------------------------+ 2933 68 | CLASS 3 SERVICE PARAMETERS | 16 Bytes 2934 +----------------------------------+ 2935 86 | CLASS 4 SERVICE PARAMETERS | 16 Bytes 2936 +----------------------------------+ 2937 102 | VENDOR VERSION LEVEL | 16 Bytes 2938 +----------------------------------+ 2939 Total Length = 116 bytes 2940 Figure 18 -- Format of PLOGI Request and ACC Payloads 2942 Details on the above fields, including common and class-based 2943 service parameters, can be found in [FC-FS]. 2945 8.3.1.8 Read Exchange Status Block (RES) 2947 ELS Format: 2949 +------+------------+------------+-----------+----------+ 2950 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2951 +------+------------+------------+-----------+----------+ 2952 | 0 | Cmd = 0x13 | 0x00 | 0x00 | 0x00 | 2953 +------+------------+------------+-----------+----------+ 2954 | 1 | Rsvd | Exchange Originator S_ID | 2955 +------+------------+------------+-----------+----------+ 2956 | 2 | OX_ID | RX_ID | 2957 +------+------------+------------+-----------+----------+ 2958 | 3-10 | Association header (may be optionally req�d) | 2959 +======+============+============+===========+==========+ 2960 | 11-12| Port name of the Exchange Originator (8 bytes) | 2961 +======+============+============+===========+==========+ 2963 iFCP Revision 9 January 2002 2965 Fields Requiring Translation Supplemental Data 2966 Address Translation Type(see (type 3 only) 2967 ------------------- section 8.2) ------------------ 2968 ----------- 2970 Exchange Originator 1, 2 or 3 Port Name of the 2971 S_ID Exchange Originator 2973 Other Special Processing: 2975 None. 2977 8.3.1.9 Read Exchange Status Block Accept 2979 Format of ELS Accept Response: 2981 +------+------------+------------+-----------+----------+ 2982 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 2983 +------+------------+------------+-----------+----------+ 2984 | 0 | Acc = 0x02 | 0x00 | 0x00 | 0x00 | 2985 +------+------------+------------+-----------+----------+ 2986 | 1 | OX_ID | RX_ID | 2987 +------+------------+------------+-----------+----------+ 2988 | 2 | Rsvd | Exchange Originator N_PORT ID | 2989 +------+------------+------------+-----------+----------+ 2990 | 3 | Rsvd | Exchange Responder N_PORT ID | 2991 +------+------------+------------+-----------+----------+ 2992 | 4 | Exchange Status Bits | 2993 +------+------------+------------+-----------+----------+ 2994 | 5 | Reserved | 2995 +------+------------+------------+-----------+----------+ 2996 | 6�n | Service Parameters and Sequence Statuses | 2997 | | as described in [FCS] | 2998 +======+============+============+===========+==========+ 2999 |n+1- | Port name of the Exchange Originator (8 bytes) | 3000 |n+2 | | 3001 +======+============+============+===========+==========+ 3002 |n+3- | Port name of the Exchange Responder (8 bytes) | 3003 |n+4 | | 3004 +======+============+============+===========+==========+ 3006 iFCP Revision 9 January 2002 3008 Fields Requiring Translation Supplemental Data 3009 Address Translation Type(see (type 3 only) 3010 ------------------- section 8.2) ------------------ 3011 ----------- 3013 Exchange Originator 1, 2 or 3 Port Name of the 3014 N_PORT I/D Exchange Originator 3016 Exchange Responder 1, 2 or 3 Port Name of the 3017 N_PORT I/D Exchange Responder 3019 When supplemental data is required, the ELS SHALL be extended by 4 3020 words as shown above. If the translation type for the Exchange 3021 Originator N_PORT I/D or the Exchange Responder N_PORT I/D is 1 or 3022 2, the corresponding 8-byte port name SHALL be set to all zeros. 3024 Other Special Processing: 3026 None. 3028 8.3.1.10 Read Link Error Status (RLS) 3030 ELS Format: 3032 +------+------------+------------+-----------+----------+ 3033 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3034 +------+------------+------------+-----------+----------+ 3035 | 0 | Cmd = 0x0F | 0x00 | 0x00 | 0x00 | 3036 +------+------------+------------+-----------+----------+ 3037 | 1 | Rsvd | N_PORT Identifier | 3038 +======+============+============+===========+==========+ 3039 | 2-3 | Port name of the N_PORT (8 bytes) | 3040 +======+============+============+===========+==========+ 3042 Fields Requiring Translation Supplemental Data (type 3043 Address Translation Type(see 3 only) 3044 ------------------- section 8.2) ------------------ 3045 ----------- 3047 N_PORT Identifier 1, 2 or 3 Port Name of the N_PORT 3049 Other Special Processing: 3051 None. 3053 8.3.1.11 Read Sequence Status Block (RSS) 3055 ELS Format: 3057 iFCP Revision 9 January 2002 3059 +------+------------+------------+-----------+----------+ 3060 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3061 +------+------------+------------+-----------+----------+ 3062 | 0 | Cmd = 0x09 | 0x00 | 0x00 | 0x00 | 3063 +------+------------+------------+-----------+----------+ 3064 | 1 | SEQ_ID | Exchange Originator S_ID | 3065 +------+------------+------------+-----------+----------+ 3066 | 2 | OX_ID | RX_ID | 3067 +======+============+============+===========+==========+ 3068 | 3-4 |Port name of the Exchange Originator (8 bytes) | 3069 +======+============+============+===========+==========+ 3071 Fields Requiring Translation Supplemental Data 3072 Address Translation Type(see (type 3 only) 3073 ------------------- section 8.2) ------------------ 3074 ----------- 3076 Exchange Originator 1, 2 or 3 Port Name of the 3077 S_ID Exchange Originator 3079 Other Special Processing: 3081 None. 3083 8.3.1.12 Reinstate Recovery Qualifier (RRQ) 3085 ELS Format: 3087 +------+------------+------------+-----------+----------+ 3088 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3089 +------+------------+------------+-----------+----------+ 3090 | 0 | Cmd = 0x12 | 0x00 | 0x00 | 0x00 | 3091 +------+------------+------------+-----------+----------+ 3092 | 1 | Rsvd | Exchange Originator S_ID | 3093 +------+------------+------------+-----------+----------+ 3094 | 2 | OX_ID | RX_ID | 3095 +------+------------+------------+-----------+----------+ 3096 | 3-10 | Association header (may be optionally req�d) | 3097 +======+============+============+===========+==========+ 3099 Fields Requiring Translation Supplemental Data 3100 Address Translation Type(see (type 3 only) 3101 ------------------- section 8.2) ------------------ 3102 ----------- 3104 Exchange Originator 1 or 2 N/A 3105 S_ID 3107 iFCP Revision 9 January 2002 3109 Other Special Processing: 3111 None. 3113 8.3.1.13 Request Sequence Initiative (RSI) 3115 ELS Format: 3117 +------+------------+------------+-----------+----------+ 3118 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3119 +------+------------+------------+-----------+----------+ 3120 | 0 | Cmd = 0x0A | 0x00 | 0x00 | 0x00 | 3121 +------+------------+------------+-----------+----------+ 3122 | 1 | Rsvd | Exchange Originator S_ID | 3123 +------+------------+------------+-----------+----------+ 3124 | 2 | OX_ID | RX_ID | 3125 +------+------------+------------+-----------+----------+ 3126 | 3-10 | Association header (may be optionally req�d) | 3127 +======+============+============+===========+==========+ 3129 Fields Requiring Translation Supplemental Data 3130 Address Translation Type(see (type 3 only) 3131 ------------------- section 8.2) ------------------ 3132 ----------- 3134 Exchange Originator 1 or 2 N/A 3135 S_ID 3137 Other Special Processing: 3139 None. 3141 8.3.1.14 Third Party Process Logout (TPRLO) 3143 TPRLO provides a mechanism for an N_PORT (third party) to remove 3144 one or more process login sessions that exist between the 3145 destination N_PORT and other N_PORTs specified in the command. 3146 This command includes one or more TPRLO LOGOUT PARAMETER PAGEs, 3147 each of which when combined with the destination N_PORT identifies 3148 a process login to be terminated by the command. 3150 iFCP Revision 9 January 2002 3152 +--------+------------+--------------------+----------------------+ 3153 | Word | Bits 31�24 | Bits 23�16 | Bits 15 - 0 | 3154 +--------+------------+--------------------+----------------------+ 3155 | 0 | Cmd = 0x24 | Page Length (0x10) | Payload Length | 3156 +--------+------------+--------------------+----------------------+ 3157 | 1 | TPRLO Logout Parameter Page 0 | 3158 +--------+--------------------------------------------------------+ 3159 | 5 | TPRLO Logout Parameter Page 1 | 3160 +--------+--------------------------------------------------------+ 3161 .... 3162 +--------+--------------------------------------------------------+ 3163 |(4*n)+1 | TPRLO Logout Parameter page n | 3164 +--------+--------------------------------------------------------+ 3165 Figure 19 -- Format of TPRLO ELS 3167 Each TPRLO parameter page contains parameters identifying one or 3168 more image pairs and may be associated with a single FC-4 protocol 3169 type, common to all FC-4 protocol types between the specified image 3170 pair, or global to all specified image pairs. The format of aTPRLO 3171 page requiring address translation is shown in Figure 20. 3172 Additional information on TPRLO can be found in [FC-FS]. 3174 +------+------------+------------+-----------+----------+ 3175 | Word | Bits 31�24 | Bits 23�16 | Bits 15-8 | Bits 7-0 | 3176 +------+------------+------------+-----------+----------+ 3177 | 0 | TYPE Code | TYPE CODE | | 3178 | | or | EXTENSION | TPRLO Flags | 3179 | | Common SVC | | | 3180 | | Parameters | | | 3181 +------+------------+------------+-----------+----------+ 3182 | 1 | Third Party Process Associator | 3183 +------+------------+------------+-----------+----------+ 3184 | 2 | Responder Process Associator | 3185 +------+------------+------------+-----------+----------+ 3186 | 3 | Reserved | Third Party Originator N_PORT ID | 3187 +======+============+============+===========+==========+ 3188 | 4-5 | World Wide Name of Third Party Originator | 3189 | | N_PORT | 3190 +------+------------------------------------------------+ 3191 Figure 20 -- Format of an Augmented TPRLO Parameter Page 3193 The TPRLO flags that affect the processing of the supplementedELS 3194 are as follows: 3196 Bit 12: Global Process logout. When set to one, this bit 3197 indicates that all image pairs for all N_PORTs of the 3198 specified FC-4 protocol shall be invalidated. When the 3199 value of this bit is one, only one logout parameter page 3200 is permitted in the TPRLO payload. 3202 Bit 13: Third party Originator N_PORT Validity. When set to 3203 one, this bit indicates that word 3, bits 23-00 (Third 3205 iFCP Revision 9 January 2002 3207 Party Originator N_PORT ID) are meaningful. 3209 If bit 13 has a value of zero and bit 12 has a value of one in the 3210 TPRLO flags field, then the ELS SHALL NOT be sent as a special ELS. 3212 Otherwise the originating gateway SHALL process the ELS as follows: 3214 a) The first word of the TPRLO payload SHALL NOT be modified. 3216 b) Each TPRLO parameter page shall be extended by two words as 3217 shown in Figure 20. 3219 c) If word 0, bit 13 (Third Party Originator N_PORT I/D validity) 3220 in the TPRLO flags field has a value of one, then the sender 3221 shall place the world-wide port name of the fibre channel 3222 device's N_PORT in the extension words. The N_PORT I/D SHALL be 3223 set to 3. Otherwise, the contents of the extension words and 3224 the Third Party Originator N_PORT ID SHALL be set to zero. 3226 d) The ELS originator SHALL set the SPC bit in the encapsulation 3227 header of each augmented frame comprising the ELS (see section 3228 6.4.1). 3230 e) If the ELS contains a single TPRLO parameter page, the 3231 originator SHALL increase the frame length as necessary to 3232 include the extended parameter page. 3234 f) If the ELS to be augmented contains multiple TPRLO parameter 3235 pages, the FC frames created to contain the augmented ELS 3236 payload SHALL NOT exceed the maximum frame size that can be 3237 accepted by the destination N_PORT. 3239 Each Fibre Channel frame SHALL contain an integer number of 3240 extended TPRLO parameter pages. The maximum number of extended 3241 TPRLO parameter pages in a frame SHALL be limited to the number 3242 that can be held without exceeding the above upper limit. New 3243 frames resulting from the extension of the TPRLO pages to 3244 include the supplemental data shall be created by extending the 3245 SEQ_CNT in the Fibre Channel frame header. The SEQ_ID SHALL NOT 3246 be modified. 3248 The gateway receiving the augmented TPRLO ELS SHALL generate ELS 3249 frames to be sent to the destination N_PORT by copying word 0 of 3250 the ELS payload and processing each augmented parameter page as 3251 follows: 3253 a) If word 0, bit 13 has a value of one, create a parameter page by 3254 copying words 0 through 2 of the augmented parameter page. The 3255 Third Party Originator N_PORT I/D in word 3 shall be generated 3257 iFCP Revision 9 January 2002 3259 by referencing the supplemental data as described in section 3260 8.2. 3262 b) If word 0, bit 13 has a value of zero, create a parameter page 3263 by copying words 0 through 3 of the augmented parameter page. 3265 The size of each frame to be sent to the destination N_PORT MUST 3266 NOT exceed the maximum frame size that the destination N_PORT can 3267 accept. The sequence identifier in each frame header SHALL be 3268 copied from the augmented ELS and the sequence count shall be 3269 monotonically increasing. 3271 8.3.1.15 Third Party Logout Accept (TPRLO ACC) 3273 The format of the TPRLO ACC frame is shown in Figure 21. 3275 +--------+------------+--------------------+----------------------+ 3276 | Word | Bits 31�24 | Bits 23�16 | Bits 15 - 0 | 3277 +--------+------------+--------------------+----------------------+ 3278 | 0 | Cmd = 0x2 | Page Length (0x10) | Payload Length | 3279 +--------+------------+--------------------+----------------------+ 3280 | 1 | TPRLO Logout Parameter Page 0 | 3281 +--------+--------------------------------------------------------+ 3282 | 5 | TPRLO Logout Parameter Page 1 | 3283 +--------+--------------------------------------------------------+ 3284 .... 3285 +--------+--------------------------------------------------------+ 3286 |(4*n)+1 | TPRLO Logout Parameter page n | 3287 +--------+--------------------------------------------------------+ 3288 Figure 21 -- Format of TPRLO ACC ELS 3290 The format of the parameter page and rules for parameter page 3291 augmentation are as specified in section 8.3.1.14. 3293 8.3.2 Special FC-4 Link Services 3295 The following sections define FC-4 link services for which special 3296 processing is required. 3298 8.3.2.1 FC-4 Link Services defined by FCP 3300 8.3.2.1.1 Read Exchange Concise (REC) 3302 Link Service Request Format: 3304 iFCP Revision 9 January 2002 3306 +------+------------+------------+-----------+----------+ 3307 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3308 +------+------------+------------+-----------+----------+ 3309 | 0 | Cmd = 0x13 | 0x00 | 0x00 | 0x00 | 3310 +------+------------+------------+-----------+----------+ 3311 | 1 | Rsvd | Exchange Originator S_ID | 3312 +------+------------+------------+-----------+----------+ 3313 | 2 | OX_ID | RX_ID | 3314 +======+============+============+===========+==========+ 3315 | 3-4 |Port name of the exchange originator (8 bytes) | 3316 | | (present only for translation type 3) | 3317 +======+============+============+===========+==========+ 3319 Fields Requiring Translation Supplemental Data 3320 Address Translation Type(see (type 3 only) 3321 ------------------- section 8.2) ------------------ 3322 ----------- 3324 Exchange Originator 1, 2 or 3 Port Name of the 3325 S_ID Exchange 3326 Originator 3328 Other Special Processing: 3330 None. 3332 8.3.2.1.2 Read Exchange Concise Accept (REC ACC) 3334 Format of REC ACC Response: 3336 iFCP Revision 9 January 2002 3338 +------+------------+------------+-----------+----------+ 3339 | Word | Bits 31�24 | Bits 23�16 | Bits 15�8 | Bits 7-0 | 3340 +------+------------+------------+-----------+----------+ 3341 | 0 | Acc = 0x02 | 0x00 | 0x00 | 0x00 | 3342 +------+------------+------------+-----------+----------+ 3343 | 1 | OX_ID | RX_ID | 3344 +------+------------+------------+-----------+----------+ 3345 | 2 | Rsvd | Exchange Originator N_PORT ID | 3346 +------+------------+------------+-----------+----------+ 3347 | 3 | Rsvd | Exchange Responder N_PORT ID | 3348 +------+------------+------------+-----------+----------+ 3349 | 4 | Data Transfer Count | 3350 +------+------------+------------+-----------+----------+ 3351 | 5 | Exchange Status | 3352 +======+============+============+===========+==========+ 3353 | 6-7 |Port name of the Exchange Originator (8 bytes) | 3354 +======+============+============+===========+==========+ 3355 | 8-9 |Port name of the Exchange Responder (8 bytes) | 3356 +======+============+============+===========+==========+ 3358 Fields Requiring Translation Supplemental Data 3359 Address Translation Type(see (type 3 only) 3360 ------------------- section 8.2) ------------------ 3361 ----------- 3363 Exchange Originator 1, 2 or 3 Port Name of the 3364 N_PORT I/D Exchange Originator 3366 Exchange Responder 1, 2 or 3 Port Name of the 3367 N_PORT I/D Exchange Responder 3369 When supplemental data is required, the frame SHALL always be 3370 extended by 4 words as shown above. If the translation type for 3371 the Exchange Originator N_PORT I/D or the Exchange Responder N_PORT 3372 I/D is 1 or 2, the corresponding 8-byte port name SHALL be set to 3373 all zeros. 3375 Other Special Processing: 3377 None. 3379 8.4 FLOGI Service Parameters Supported by an iFCP Gateway 3381 The FLOGI ELS is issued by an N_PORT that wishes to access the 3382 fabric transport services. 3384 The format of the FLOGI request and FLOGI ACC payloads are 3385 identical to the PLOGI request and ACC payloads described in 3386 section 8.3.1.7. The figure in that section is duplicated below 3387 for convenience. 3389 iFCP Revision 9 January 2002 3391 Byte 3392 Offset 3393 +----------------------------------+ 3394 0 | LS_COMMAND | 4 Bytes 3395 +----------------------------------+ 3396 4 | COMMON SERVICE PARAMETERS | 16 Bytes 3397 +----------------------------------+ 3398 20 | PORT NAME | 8 Bytes 3399 +----------------------------------+ 3400 28 | NODE NAME | 8 Bytes 3401 +----------------------------------+ 3402 36 | CLASS 1 SERVICE PARAMETERS | 16 Bytes 3403 +----------------------------------+ 3404 52 | CLASS 2 SERVICE PARAMETERS | 16 Bytes 3405 +----------------------------------+ 3406 68 | CLASS 3 SERVICE PARAMETERS | 16 Bytes 3407 +----------------------------------+ 3408 86 | CLASS 4 SERVICE PARAMETERS | 16 Bytes 3409 +----------------------------------+ 3410 102 | VENDOR VERSION LEVEL | 16 Bytes 3411 +----------------------------------+ 3412 Figure 22 -- FLOGI Request and ACC Payload Format 3414 A full description of each parameter is given in [FC-FS]. 3416 This section tabulates the protocol-dependant service parameters 3417 supported by a fabric port attached to an iFCP gateway. 3419 The service parameters carried in the payload of an FLOGI extended 3420 link service request MUST be set in accordance with 3421 Table 4. 3423 iFCP Revision 9 January 2002 3425 +-----------------------------------------+---------------+ 3426 | | Fabric Login | 3427 | Service Parameter | Class | 3428 | +---+---+---+---+ 3429 | | 1 | 2 | 3 | 4 | 3430 +-----------------------------------------+---+---+---+---+ 3431 | Class Validity | n | M | M | n | 3432 +-----------------------------------------+---+---+---+---+ 3433 | Service Options | | 3434 +-----------------------------------------+---+---+---+---+ 3435 | Intermix Mode | n | n | n | n | 3436 +-----------------------------------------+---+---+---+---+ 3437 | Stacked Connect-Requests | n | n | n | n | 3438 +-----------------------------------------+---+---+---+---+ 3439 | Sequential Delivery | n | M | M | n | 3440 +-----------------------------------------+---+---+---+---+ 3441 | Dedicated Simplex | n | n | n | n | 3442 +-----------------------------------------+---+---+---+---+ 3443 | Camp on | n | n | n | n | 3444 +-----------------------------------------+---+---+---+---+ 3445 | Buffered Class 1 | n | n | n | n | 3446 +-----------------------------------------+---+---+---+---+ 3447 | Priority | n | n | n | n | 3448 +-----------------------------------------+---+---+---+---+ 3449 | Initiator/Recipient Control | | 3450 +-----------------------------------------+---+---+---+---+ 3451 | Clock synchronization ELS capable | n | n | n | n | 3452 +-----------------------------------------+---+---+---+---+ 3453 Table 4 -- FLOGI Service Parameter Settings 3455 Notes: 3457 1) "n" indicates a parameter or capability that is not 3458 supported by the iFCP protocol. 3460 2) "M" indicates an applicable parameter that MUST be 3461 supported by an iFCP gateway. 3463 9. iFCP Error Detection 3465 9.1 Overview 3467 [FC-FS] defines error detection and recovery procedures. These 3468 Fibre Channel-defined mechanisms continue to be available in the 3469 iFCP environment. 3471 9.2 Stale Frame Prevention 3473 Recovery from Fibre Channel protocol error conditions requires that 3474 frames associated with a failed or aborted Exchange drain from the 3475 fabric before Exchange resources can be safely reused. 3477 iFCP Revision 9 January 2002 3479 Since a Fibre Channel fabric may not preserve frame order, there is 3480 no deterministic way to purge such frames. Instead, the fabric 3481 guarantees that frame the lifetime will not exceed a specific limit 3482 (R_A_TOV). 3484 R_A_TOV is defined in [FC-FS] as "the maximum transit time within a 3485 fabric to guarantee that a lost frame will never emerge from the 3486 fabric". For example, a value of 2 x R_A_TOV is the minimum time 3487 that the originator of an ELS request or FC-4 link service request 3488 must wait for the response to that request. The Fibre Channel 3489 default value for R_A_TOV is 10 seconds. 3491 An iFCP gateway SHALL actively enforce limits on R_A_TOV as 3492 described in section 9.2.1. 3494 9.2.1 Enforcing R_A_TOV Limits 3496 The R_A_TOV limit on frame lifetimes SHALL be enforced by means of 3497 the time stamp in the encapsulation header (see section 6.4.1) as 3498 described in this section. 3500 The budget for R_A_TOV SHOULD include allowances for the 3501 propagation delay through the gateway regions of the sending and 3502 receiving N_PORTs plus the propagation delay through the IP 3503 network. This latter component is referred to in this 3504 specification as IP_TOV. 3506 IP_TOV should be set well below the value of R_A_TOV specified for 3507 the iFCP fabric and should be stored in the iSNS server. IP_TOV 3508 should be set to 50 percent of R_A_TOV. 3510 The following paragraphs describe the requirements for 3511 synchronizing gateway time bases and the rules for measuring and 3512 enforcing propagation delay limits. 3514 The protocol for synchronizing a gateway time base is SNTP 3515 [RFC2030]. In order to insure that all gateways are time-aligned, a 3516 gateway SHOULD obtain the address of an SNTP-compatible time server 3517 via an iSNS query. If multiple time server addresses are returned 3518 by the query, the servers must be synchronized and the gateway may 3519 use any server in the list. Alternatively, the server may return a 3520 multicast group address in support of operation in Anycast mode. 3521 Implementation of Anycast mode is as specified in [RFC2030], 3522 including the precautions defined in that document. Multicast mode 3523 SHOULD NOT be used. 3525 An SNTP server may use any one of the time reference sources listed 3526 in [RFC2030]. The resolution of the time reference MUST be 125 3527 milliseconds or better. 3529 Stability of the SNTP server and gateway time bases should be 100 3530 ppm or better. 3532 iFCP Revision 9 January 2002 3534 With regard to its time base, the gateway is in either the 3535 Synchronized or Unsynchronized state. When in the Unsynchronized 3536 state, the gateway SHALL: 3538 a) Set the time stamp field to 0,0 for all outgoing frames 3540 b) Ignore the time stamp field for all incoming frames. 3542 When in the synchronized state, the gateway SHALL 3544 a) Set the time stamp field for each outgoing frame in accordance 3545 with the gateway's internal time base 3547 b) Check the time stamp field of each incoming frame, following 3548 validation of the encapsulation header CRC as described in 3549 section 6.4.4. 3551 c) If the incoming frame has a time stamp of 0,0, the receiving 3552 gateway SHALL NOT test the frame to determine if it is stale. 3554 d) If the incoming frame has a non-zero time stamp, the receiving 3555 gateway SHALL compute the absolute value of the time in flight 3556 and SHALL compare it against the value of IP_TOV specified for 3557 the IP fabric. 3559 e) If the result in step (d) exceeds IP_TOV, the encapsulated 3560 frame shall be discarded. Otherwise, the frame shall be de- 3561 encapsulated as described in section 6.4.4. 3563 A gateway SHALL enter the Synchronized state upon receiving a 3564 successful response to an SNTP query. 3566 A gateway shall enter the Unsynchronized state: 3568 a) Upon power up and before successful completion of an SNTP query 3570 b) Whenever the gateway looses contact with the SNTP server such 3571 that the gateway's time base may no longer be in alignment with 3572 that of the SNTP server. The criterion for determining loss of 3573 contact is implementation specific. 3575 Following loss of contact, it is recommended that the gateway enter 3576 the Unsynchronized state when the estimated time base drift 3577 relative to the SNTP reference is greater than ten percent of the 3578 IP_TOV limit. (Assuming all timers have an accuracy of 100 ppm and 3579 IP_TOV equals 5 seconds, the maximum allowable loss of contact 3580 duration would be about 42 minutes.) 3582 In response to loss of synchronization, a gateway enforcing R_A_TOV 3583 limits as described in this section should abort all N_PORT login 3584 sessions as described in section 6.2.3.2. 3586 iFCP Revision 9 January 2002 3588 10. Fabric Services Supported by an iFCP implementation 3590 An iFCP gateway implementation MUST support the following fabric 3591 services: 3593 N_PORT ID Value Description Section 3594 --------------- ----------- ------- 3595 0xFF-FF-FE F_PORT Server 10.1 3597 0xFF-FF-FD Fabric Controller 10.2 3599 0xFF-FF-FC Directory/Name Server 10.3 3601 In addition, an iFCP gateway MAY support the FC broadcast server 3602 functionality described in section 10.4. 3604 10.1 F_PORT Server 3606 The F_PORT server SHALL support the FLOGI ELS as described in 3607 section 8.4 as well as the following ELSs specified in [FC-FS]: 3609 a) Request for fabric service parameters (FDISC), 3611 b) Request for the link error status (RLS), 3613 c) Read Fabric Timeout Values (RTV). 3615 10.2 Fabric Controller 3617 The Fabric Controller SHALL support the following ELSs as specified 3618 in [FC-FS]: 3620 a) State Change Notification (SCN), 3622 b) Registered State Change Notification (RSCN), 3624 c) State Change Registration (SCR). 3626 10.3 Directory/Name Server 3628 The Directory/Name server provides a registration service allowing 3629 an N_PORT to record or query the database for information about 3630 other N_PORTs. The services are defined in [FC-GS3]. The queries 3631 are issued as FC-4 transactions using the FC-CT command transport 3632 protocol specified in [FC-GS3]. 3634 iFCP Revision 9 January 2002 3636 In iFCP, name server requests are translated to the iSNS queries 3637 defined in [ISNS]. The definitions of name server objects are 3638 specified in [FC-GS3]. 3640 The name server SHALL support record and query operations for 3641 directory subtype 0x02 (Name Server) and 0x03 (IP Address Server) 3642 and MAY support the FC-4 specific services as defined in [FC-GS3]. 3644 10.4 Broadcast Server 3646 Fibre Channel frames are broadcast throughout the fabric by 3647 addressing them to the Fibre Channel broadcast server at well-known 3648 Fibre Channel address 0xFF-FF-FF. The broadcast server then 3649 replicates and delivers the frame to each attached N_PORT in all 3650 zones to which the originating device belongs. Only class 3 3651 (datagram) service is supported. 3653 In an iFCP system, the Fibre Channel broadcast function is emulated 3654 by means of a two-tier architecture comprised of the following 3655 elements: 3657 a) A local broadcast server residing in each iFCP gateway. The 3658 local server distributes broadcast traffic within the gateway 3659 region and forwards outgoing broadcast traffic to a global 3660 server for distribution throughout the network. 3662 b) A global broadcast server which re-distributes broadcast 3663 traffic to the local server in each participating gateway. 3665 c) An iSNS discovery domain defining the scope over which 3666 broadcast traffic is propagated. The discovery domain is 3667 populated with a global broadcast server and the set of local 3668 servers it supports. 3670 The local and global broadcast servers are logical iFCP devices 3671 that communicate using the iFCP protocol. The servers have an 3672 N_PORT Network Address consisting of an iFCP portal address and an 3673 N_PORT I/D set to the well-known Fibre Channel address of the FC 3674 broadcast server (0xff-ff-ff). 3676 As noted above, an N_PORT originates a broadcast by directing frame 3677 traffic to the Fibre Channel broadcast server. The gateway-resident 3678 local server distributes a copy of the frame locally and forwards a 3679 copy to the global server for redistribution to the local servers 3680 on other gateways. The global server MUST NOT echo a broadcast 3681 frame to the originating local server. 3683 10.4.1 Establishing the Broadcast Configuration 3685 The broadcast configuration is managed using facilities provided by 3686 the iSNS server. Specifically: 3688 iFCP Revision 9 January 2002 3690 a) An iSNS discovery domain is created and seeded with the network 3691 address of the global broadcast server N_PORT. The global 3692 server is identified as such by setting the appropriate N_PORT 3693 entity attribute. 3695 b) Using the management interface, each broadcast server is preset 3696 with the identity of the broadcast domain. 3698 During power up, each gateway SHALL invoke the iSNS service to 3699 register its local broadcast server in the broadcast discovery 3700 domain. After registration, the local server SHALL wait for the 3701 global broadcast server to establish an iFCP session. 3703 The global server SHALL register with the iSNS server as follows: 3705 a) The server SHALL query the iSNS name server by attribute to 3706 obtain the world-wide port name of the N_PORT pre-configured to 3707 provide global broadcast services. 3709 b) If the world-wide port name obtained above does not correspond 3710 to that of the server issuing the query, the N_PORT SHALL NOT 3711 perform global broadcast functions for N_PORTs in that discovery 3712 domain. 3714 c) Otherwise, the global server N_PORT shall register with the 3715 discovery domain and query the iSNS server to identify all 3716 currently-registered local servers. 3718 d) The global broadcast server shall initiate an iFCP session with 3719 each local broadcast server in the domain. When a new local 3720 server registers, the global server SHALL receive a state change 3721 notification and respond by initiating an iFCP session with the 3722 newly added server. The gateway SHALL obtain these 3723 notifications using the iSNS provisions for lossless delivery. 3725 Upon receiving the CBIND request to initiate the iFCP session, the 3726 local server SHALL record the world-wide port name and N_PORT 3727 network address of the global server. 3729 10.4.2 Broadcast Session Management 3731 After the initial broadcast session is established, the local or 3732 global broadcast server MAY choose to manage the session in one of 3733 the following ways depending on resource requirements and the 3734 anticipated level of broadcast traffic: 3736 a) A server MAY keep the session open continuously. Since 3737 broadcast sessions are often quiescent for long periods of 3738 time, the server SHOULD monitor session connectivity as 3739 described in section 6.2.2.2. 3741 iFCP Revision 9 January 2002 3743 b) A server MAY open the broadcast session on demand, only when 3744 broadcast traffic is to be sent. If the session is reopened by 3745 the global server, the local server SHALL replace the 3746 previously recorded network address of the global broadcast 3747 server. 3749 11. iFCP Security 3751 11.1 Overview 3753 iFCP relies upon the IPSec protocol suite to provide data 3754 confidentiality and authentication services and IKE as the key 3755 management protocol. Section 11.2 describes the security 3756 requirements arising from iFCP�s operating environment while 3757 Section 11.3 describes the resulting design choices, their 3758 requirement levels, and how they apply to the iFCP protocol. 3760 11.2 iFCP Security Operating Requirements 3762 11.2.1 Context 3764 iFCP is a protocol designed for use by gateway devices deployed in 3765 enterprise data centers. Such environments typically have security 3766 gateways designed to provide network security through isolation 3767 from public networks. Furthermore, iFCP data may need to traverse 3768 security gateways in order to support SAN-to-SAN connectivity 3769 across public networks. 3771 11.2.2 Security Threats 3773 Communicating iFCP gateways are vulnerable to attacks. Examples of 3774 attacks include attempts by an adversary to: 3776 a) Acquire confidential data and identities by snooping data 3777 packets. 3779 b) Modify packets containing iFCP data and control messages. 3781 c) Inject new packets into the iFCP session. 3783 d) Hijack the TCP connection carrying the iFCP session. 3785 e) Launch denial of service attacks against the iFCP gateway. 3787 f) Disrupt security negotiation process. 3789 g) Impersonate a legitimate security gateway. 3791 h) Compromise communication with the iSNS server. 3793 It is imperative to thwart these attacks, given that an iFCP 3794 gateway is the last line of defense for a whole Fibre Channel 3796 iFCP Revision 9 January 2002 3798 island, which may include several hosts and switches. To do so, the 3799 iFCP protocol MUST define confidentiality, authentication, 3800 integrity, and replay protection on a per-datagram basis. It also 3801 MUST define a scalable approach to key management. Conformant 3802 implementations of the iFCP protocol MAY use such definitions. 3804 11.2.3 Interoperability Requirements with Security Gateways 3806 Enterprise data center networks are considered mission-critical 3807 facilities that must be isolated and protected from all possible 3808 security threats. Such networks are usually protected by security 3809 gateways, which at a minimum provide a shield against denial of 3810 service attacks. The iFCP security architecture must be able to 3811 leverage the protective services of the existing security 3812 infrastructure, including firewall protection, NAT and NAPT 3813 services, and IPSec VPN services available on existing security 3814 gateways. 3816 11.2.4 Statically and Dynamically Assigned IP Addresses 3818 As iFCP gateways and switches are deployed within enterprise 3819 networks, it is expected that, like most routers and switches, 3820 gateway IP addresses will be statically assigned. Consequently, 3821 IKE and IPSec features focused on supporting DHCP and other dynamic 3822 IP address assignment capabilities for mobile hosts are not 3823 strictly required. Since the iFCP protocol cannot rule out the use 3824 of dynamically assigned IP addresses however, the security 3825 definitions for the iFCP protocol shall not exhibit any 3826 vulnerability in the case of dynamically assigned IP addresses 3827 (e.g., via DHCP [RFC2131]). 3829 11.2.5 Authentication Requirements 3831 iFCP is a peer-to-peer protocol. iFCP sessions may be initiated by 3832 either or both peer gateways. Consequently, bi-directional 3833 authentication of peer gateways MUST be provided. 3835 Fibre Channel, operating system and user identities are transparent 3836 to the iFCP protocol. IKE and IPSec authentication used to protect 3837 iFCP traffic shall be based upon the IP addresses of the 3838 communicating peer gateways. 3840 iFCP gateways shall use Discovery Domain information obtained from 3841 the iSNS server [ISNS] to determine whether the initiating Fibre 3842 Channel N_PORT should be allowed access to the target N_PORT. 3843 N_PORT identities used in the Port Login (PLOGI) process shall be 3844 considered authenticated provided the PLOGI request is received 3845 from the remote gateway over a secure, IPSec-protected connection. 3847 There is no requirement that the identities used in authentication 3848 be kept confidential. 3850 iFCP Revision 9 January 2002 3852 11.2.6 Confidentiality Requirements 3854 iFCP traffic may traverse insecure public networks, and therefore 3855 implementations MUST have per-packet encryption capabilities to 3856 provide confidentiality. 3858 11.2.7 Rekeying Requirements 3860 Due to the high data transfer rates and the amount of data 3861 involved, an iFCP gateway implementation MUST support the 3862 capability to rekey each phase 2 security association in time 3863 intervals as often as every 25 seconds. The iFCP gateway MUST 3864 provide the capability for forward secrecy in the rekeying process. 3866 11.2.8 Usage Requirements 3868 It must be possible for compliant iFCP implementations to 3869 administratively disable any and all security mechanisms. It must 3870 also be possible to apply different security requirements to 3871 individual N_PORT login session. Implementations may elect to 3872 expose such fine level of control through a management interface or 3873 through interaction with the iSNS. 3875 11.2.9 iSNS Role 3877 iSNS [ISNS] is an invariant in all iFCP deployments. iFCP gateways 3878 use iSNS for discovery services, and MAY use security policies 3879 configured in the iSNS database as the basis for algorithm 3880 negotiation in IKE. The iSNS specification defines mechanisms to 3881 secure communication between an iFCP gateway and iSNS server(s). 3882 Additionally, such specification indicates how elements of security 3883 policy concerning individual iFCP sessions can be retrieved from 3884 iSNS server(s). 3886 11.3 iFCP Security Design 3888 11.3.1 Enabling Technologies 3890 Applicable technology from IPsec and IKE is defined in the 3891 following suite of specifications: 3893 [RFC2401] Security Architecture for the Internet Protocol 3895 [RFC2402] IP Authentication Header 3897 [RFC2404] The Use of HMAC-SHA-1-96 Within ESP and AH 3899 [RFC2405] The ESP DES-CBC Cipher Algorithm With Explicit IV 3901 [RFC2406] IP Encapsulating Security Payload 3903 iFCP Revision 9 January 2002 3905 [RFC2407] The Internet IP Security Domain of Interpretation for 3906 ISAKMP 3908 [RFC2408] Internet Security Association and Key Management 3909 Protocol (ISAKMP) 3911 [RFC2409] The Internet Key Exchange (IKE) 3913 [RFC2410] The NULL Encryption Algorithm and Its use with IPSEC 3915 [RFC2451] The ESP CBC-Mode Cipher Algorithms 3917 [RFC2709] Security Model with Tunnel-mode IPsec for NAT Domains 3919 The implementation of IPsec and IKE is required according the 3920 following guidelines. 3922 Support for the IP Encapsulating Security Payload (ESP) [RFC2406] 3923 is MANDATORY to implement. As stated in [RFC2406], the following 3924 authentication algorithms MUST be implemented: 3926 a) HMAC with SHA1 [RFC2404] 3928 b) NULL authentication 3930 The Advanced Encryption Standard [AES] in CBC MAC mode with 3931 Extended Cipher Block Chaining [XCBC] SHOULD be implemented. 3933 The following encryption algorithms MUST be implemented: 3935 a) NULL encryption [RFC2410] 3937 b) 3DES in CBC mode [RFC2451] 3939 AES counter mode encryption [AESCTR] SHOULD be implemented. 3941 Implementation of DES in CBC mode [RFC2405] is OPTIONAL. It is 3942 recommended that DES in CBC mode SHOULD NOT be used due to its 3943 inherent weakness. It is in fact well known that DES is crackable 3944 with modest computation resources, and so is inappropriate for use 3945 in any iFCP deployment scenario requiring levels of security. 3947 A conformant iFCP protocol implementation MUST implement IPsec ESP 3948 [RFC2406] in tunnel mode [RFC2401]. If minimizing the size of IPsec 3949 headers is a concern, transport mode should be supported. It shall 3950 be noted that transport mode continues to have a MUST implement 3951 requirement in those host scenarios where [RFC2401] makes it a MUST 3952 (see Sections 3.3 and 4.1 of [RFC2401]). 3954 iFCP Revision 9 January 2002 3956 Regarding key management, iFCP implementations MUST support IKE 3957 [RFC2409] for peer authentication, negotiation of security 3958 associations, and key management, using the IPsec DOI. Manual 3959 keying MUST NOT be used since it does not provide the necessary 3960 keying support. According to [RFC2409], pre-shared secret key 3961 authentication is MANDATORY to implement, whereas certificate-based 3962 peer authentication using digital signatures MAY be implemented 3963 (see section 11.3.3 regarding the use of certificates). [RFC2409] 3964 defines the following requirement levels for IKE Modes: 3966 Phase-1 Main Mode MUST be implemented 3968 Phase-1 Aggressive Mode SHOULD be implemented 3970 Phase-2 Quick Mode MUST be implemented 3972 Phase-2 Quick Mode with key exchange payload MUST be implemented. 3974 Phase-1 Main Mode SHOULD NOT be used in conjunction with pre-shared 3975 keys, due to Main Mode�s vulnerability to men-in-the-middle- 3976 attackers when group pre-shared keys are used. iFCP therefore 3977 requires that Aggressive Mode MUST be implemented as a valid 3978 alternative to Main Mode. 3980 Peer authentication using the public key encryption methods 3981 outlined in sections 5.2 and 5.3 of [RFC2409] SHOULD NOT be used. 3983 In all Phase 1 Modes, iFCP MUST use IP addresses as identities. 3985 The Phase 2 Quick Mode exchanges used to negotiate protection for 3986 the TCP connections used by iFCP MUST explicitly carry the Identity 3987 Payload fields (IDci and IDcr). The DOI [RFC2407] provides for 3988 several types of identification data. However, when used in 3989 conformant iFCP security implementations, each ID Payload MUST 3990 carry a single IP address and a single non-zero TCP port number, 3991 and MUST NOT use the IP Subnet or IP Address Range formats. This 3992 allows the Phase 2 security association to correspond to specific 3993 TCP and iFCP connections. 3995 11.3.2 Use of IKE and IPsec 3997 Each IP address supporting iFCP communication shall be capable of 3998 establishing one or more Phase-1 IKE Security Associations (SA) to 3999 other IP addresses configured as peer iFCP gateways, using the IP 4000 address as the identity. Such a security association may be 4001 established at a gateway�s initialization time, or may be deferred 4002 until the first TCP connection with security requirements is 4003 established. 4005 iFCP Revision 9 January 2002 4007 Unlike Phase-1 SAs, a Phase-2 SA maps to an individual TCP 4008 connection. It protects the setup process of the underlying TCP 4009 connection and all its subsequent TCP traffic. TCP connections 4010 protected by the phase 2 SA are either in the unbound state, or are 4011 bound to a specific N_PORT login session. The creation of an IKE 4012 Phase-2 SA may be triggered by a policy rule supplied through a 4013 management interface, or by N_PORT properties registered with the 4014 iSNS server. Similarly, the use of Key Exchange payload in Quick 4015 Mode for perfect forward secrecy may be dictated through a 4016 management interface or by N_PORT properties registered with the 4017 iSNS server. This specification allows multiple implementation 4018 strategies, in which the establishment of an IKE Phase-2 SA occurs 4019 at different times. Examples of implementation strategies include: 4021 a) The definition of a unique security policy for all TCP 4022 connections regardless of their bound or unbound state. Thus, an 4023 unbound TCP connection can be bound to an N_PORT login session 4024 without the need to incur a new IKE Phase-2 SA. 4026 b) Multiple security policies for unbound TCP connections and 4027 active N_PORT login sessions. In this case, an unbound TCP 4028 connection becomes bound to an N_PORT login session after 4029 establishing a new IKE Phase-2 SA matching the new security 4030 policy for that N_PORT session. 4032 c) The implementation does not support unbound connections. In this 4033 case, a new IKE Phase-2 SA and TCP connection must be started 4034 from scratch anytime a new N_PORT login session is created. 4036 If the implementation does use unbound TCP connections, then an IKE 4037 Phase-2 SA MUST protect each of such unbound connections. 4039 As expected, the successful establishment of a IKE Phase-2 SA 4040 results in the creation of two uni-directional IPsec SAs fully 4041 qualified by the tuple . 4043 Should a TCP connection be torn down (as opposed to joining a pool 4044 of unbound connections), the associated Phase-2 SA SHALL be 4045 terminated upon expiration of the TIME WAIT timeout value 4046 (according to [RFC793]). 4048 Upon receiving a Phase 1 delete message, an iFCP implementation 4049 SHALL tear down all the Phase 2 SAs spawned from that Phase 1 SA, 4050 followed by the Phase 1 SA itself. Upon receiving a Phase 2 delete 4051 message, iFCP implementations will behave according to the state of 4052 the TCP connection protected by the SA in question. If the TCP 4053 session was terminated (either via FINs or RSTs), then a Phase 2 4054 delete message SHALL terminate the IPsec SAs and any state formerly 4055 associated with that Phase 2 SA. If, however, the TCP session is 4056 maintained, then a Phase 2 delete message shall trigger a new Quick 4057 Mode exchange. To minimize the use of SA resources while the TCP 4059 iFCP Revision 9 January 2002 4061 connection is idle, the creation of the security association may be 4062 deferred until data is sent over the connection. 4064 11.3.3 Signatures and Certificate-based authentication 4066 Conformant iFCP implementations MAY support peer authentication via 4067 digital signatures and X.509 certificates. When X.509 certificate 4068 authentication is chosen within IKE, each iFCP gateway needs the 4069 certificate credentials of each peering iFCP gateway in order to 4070 establish a security association with that peer. 4072 Certificate credentials used by iFCP gateways MUST be those of the 4073 machine. Certificate credentials MAY be bound to the interface (IP 4074 Address) of the iFCP gateway used for the iFCP session, or the 4075 fabric WWN of the iFCP gateway itself. Since the value of a machine 4076 certificate is inversely proportional to the ease with which an 4077 attacker can obtain one under false pretenses, it is advisable that 4078 the machine certificate enrollment process be strictly controlled. 4079 For example, only administrators may have the ability to enroll a 4080 machine with a machine certificate. User certificates SHOULD NOT be 4081 used by iFCP gateways for establishment of SA's protecting iFCP 4082 sessions. 4084 If the gateway does not have the peer iFCP gateway's certificate 4085 credentials, then it can obtain them by 4087 a) Using the iSNS protocol to query for the peer gateway's 4088 certificate(s) stored in a trusted iSNS server, or 4090 b) Through use of the ISAKMP Certificate Request Payload (CRP) 4091 [RFC2408] to request the certificate(s) directly from the peer 4092 iFCP gateway. 4094 When certificate chains are long enough, then IKE exchanges using 4095 UDP as the underlying transport may yield IP fragments, which are 4096 known to work poorly across some intervening routers, firewalls, 4097 and NA(P)T boxes. As a result, the endpoints may be unable to 4098 establish an IPsec security association. The solutions to this 4099 problem are to send the end-entry machine certificate rather than 4100 the chain, to reduce the size of the certificate chain, to use IKE 4101 implementations over a reliable transport protocol (e.g., TCP) 4102 assisted by Path MTU discovery and code against black-holing as in 4103 [RFC2923], or to install network components that can properly 4104 handle fragments. 4106 IKE negotiators SHOULD check the pertinent Certificate Revocation 4107 List (CRL) [RFC2408] before accepting a certificate for use in 4108 IKE's authentication procedures. 4110 11.4 iSNS and iFCP Security 4111 iFCP Revision 9 January 2002 4113 iFCP is required to use iSNS for discovery and management services. 4114 Consequently, the security of the iSNS protocol has an impact on 4115 the security of iFCP gateways. In particular, the following 4116 threats exist: 4118 a) An attacker could alter iSNS protocol messages, so as to direct 4119 iFCP gateways to establish connections with rogue peer devices, 4120 or to weaken/eliminate IPSec protection for iFCP traffic. 4122 b) An attacker could masquerade as the real iSNS server using false 4123 iSNS heartbeat messages. This could cause iFCP gateways to use 4124 rogue iSNS servers. 4126 c) An attacker could gain knowledge about iFCP gateways by snooping 4127 iSNS protocol messages. Such information could aid an attacker 4128 in mounting a direct attack on iFCP gateways, such as a denial- 4129 of-service attack or outright physical theft. 4131 To address these threats, the following capabilities are required: 4133 a) Unicast iSNS protocol messages need to have both confidentiality 4134 and authentication support. 4136 b) Multicast iSNS protocol messages such as the iSNS heartbeat 4137 message need to have authentication support. 4139 There is no requirement that the communicating identities in iSNS 4140 protocol messages be kept confidential. Specifically, the identity 4141 and location of the iSNS server shall not be considered 4142 confidential. 4144 However, in order to protect against an attacker masquerading as 4145 the real iSNS server, the iSNS server MUST have the capability to 4146 allow client gateways to authenticate broadcast or multicast 4147 messages such as the iSNS heartbeat. The iSNS authentication block 4148 (which is identical in format to the SLP authentication block) may 4149 be used for this purpose. Note that the authentication block is 4150 used only for iSNS broadcast or multicast messages, and SHOULD NOT 4151 be used in unicast iSNS messages. 4153 For protecting unicast iSNS protocol messages, iSNS servers MUST 4154 support the ESP protocol in tunnel mode for iFCP client gateways. 4156 11.5 Use of iSNS to Distribute Security Policy 4158 Once communication between iFCP gateways and the iSNS server have 4159 been secured through use of IPSec, the iFCP gateways have the 4160 capability to discover the security settings that they need to use 4161 to protect iFCP traffic. This provides a potential scaling 4162 advantage over device-by-device configuration of individual 4163 security policies for each iFCP gateway. 4165 iFCP Revision 9 January 2002 4167 The iSNS server stores security settings for each iFCP gateway. 4168 These security settings include use or non-use of IPSec, IKE, Main 4169 Mode, Aggressive Mode, PFS, Pre-shared Key, and certificates. These 4170 settings can be retrieved by peer iFCP gateways, who can then take 4171 the appropriate action. For example, IKE may not be enabled for a 4172 particular iFCP gateway. If a peer gateway can learn of this in 4173 advance by consulting the iSNS server, it will not need to waste 4174 time and resources attempting to initiate an IKE session with that 4175 iFCP gateway. 4177 Additionally, the iSNS server can store policies that are used for 4178 ISAKMP phase 1 and phase 2 negotiations between iFCP gateways. The 4179 ISAKMP payload format includes a series of one or more proposals 4180 that the iFCP gateway will use when negotiating the appropriate 4181 IPSec policy to use to protect iFCP traffic. 4183 11.6 Minimal Security Policy for an iFCP gateway 4185 An iFCP implementation MAY be able to administratively disable 4186 security mechanisms for individual N_PORT login sessions. This 4187 implies that IKE and IPsec security associations may not be 4188 established for one or more of such sessions. A configuration of 4189 this type may be accomplished through a management interface or 4190 through attributes set in the iSNS server. 4192 For most IP networks, it is inappropriate to assume physical 4193 security, administrative security, and correct configuration of the 4194 network and all attached nodes (a physically isolated network in a 4195 test lab may be an exception). Therefore, authentication SHOULD be 4196 used in order to provide a minimal assurance that connections have 4197 initially been opened with the intended counterpart. The minimal 4198 iFCP security policy thus only states that an iFCP gateway SHOULD 4199 authenticate its iSNS server(s) as described in [ISNS]. 4201 12. Quality of Service Considerations 4203 12.1 Minimal requirements 4205 Conforming iFCP protocol implementations SHALL correctly 4206 communicate gateway-to-gateway even across one or more intervening 4207 best-effort IP regions. The timings with which such gateway-to 4208 gateway communication is performed, however, will greatly depend 4209 upon BER, packet losses, latency, and jitter experienced throughout 4210 the best-effort IP regions. The higher these parameters, the higher 4211 will be the gap measured between iFCP observed behaviors and 4212 baseline iFCP behaviors (i.e., as produced by two iFCP gateways 4213 directly connected to one another). 4215 12.2 High-assurance 4217 It is expected that many iFCP deployments will benefit from a high 4218 degree of assurance regarding the behavior of intervening IP 4220 iFCP Revision 9 January 2002 4222 regions, with resulting high-assurance on the overall end-to-end 4223 path, as directly experienced by Fibre Channel applications. Such 4224 assurance on the IP behaviors stems from the intervening IP regions 4225 supporting standard Quality-of-Service (QoS) techniques, fully 4226 complementary to iFCP, such as: 4228 a) Congestion avoidance by over-provisioning of the network 4230 b) Integrated Services [RFC1633] QoS 4232 c) Differentiated Services [RFC2475] QoS 4234 d) Multi-Protocol Label Switching [RFC3031]. 4236 One may load an MPLS forwarding equivalence class (FEC) with QoS 4237 class significance, in addition to other considerations such as 4238 protection and diversity for the given path. The complementarity 4239 and compatibility of MPLS with Differentiated Services is 4240 explored in [MPSLDS], wherein the PHB bits are copied to the EXP 4241 bits of the MPLS shim header. 4243 In the most general definition, two iFCP gateways are separated by 4244 one or more independently managed IP regions, some of which 4245 implement some of the QoS solutions mentioned above. A QoS-capable 4246 IP region supports the negotiation and establishment of a service 4247 contract specifying the forwarding service through the region. Such 4248 contract and its negotiation rules are outside the scope of this 4249 document. In the case of IP regions with DiffServ QoS, the reader 4250 should refer to Service Level Specifications (SLS) and Traffic 4251 Conditioning Specifications (TCS) (as defined in [DIFTERM]). Other 4252 aspects of a service contract are expected to be non-technical and 4253 thus outside of the IETF scope. 4255 Due to the fact that Fibre Channel Class 2 and Class 3 do not 4256 currently support fractional bandwidth guarantees, and that iFCP is 4257 committed to supporting Fibre Channel semantics, it is impossible 4258 for an iFCP gateway to autonomously infer bandwidth requirements 4259 from streaming Fibre Channel traffic. Rather, the requirements on 4260 bandwidth or other network parameters need to be administratively 4261 set into an iFCP gateway, or into the entity that will actually 4262 negotiate the forwarding service on the gateway's behalf. Depending 4263 on the QoS techniques available, the stipulation of a forwarding 4264 service may require interaction with network ancillary functions 4265 such admission control and bandwidth brokers (via RSVP or other 4266 signalling protocols that an IP region may accept). 4268 The administrator of a iFCP gateway may negotiate a forwarding 4269 service with IP region(s) for one, several, or all of an iFCP 4270 gateway's TCP sessions used by an iFCP gateway. Alternately, this 4271 responsibility may be delegated to a node downstream. Since one TCP 4272 connection is dedicated to each N_PORT login session , the traffic 4274 iFCP Revision 9 January 2002 4276 in an individual N_PORT to N_PORT session can be singled out by 4277 iFCP-unaware network equipment as well. 4279 To render the best emulation of Fibre Channel possible over IP, it 4280 is anticipated that typical forwarding services will specify a 4281 fixed amount of bandwidth, null losses, and, to a lesser degree of 4282 relevance, low latency, and low jitter. For example, an IP region 4283 using DiffServ QoS may support SLSs of this nature by applying EF 4284 DSCPs to the iFCP traffic. 4286 13. Author's Addresses 4288 Charles Monia Franco Travostino 4289 Rod Mullendore Director, Content 4290 Josh Tseng Internetworking Lab, 4291 Nortel Networks 4292 Nishan Systems 3 Federal Street 4293 3850 North First Street Billerica, MA 01821 4294 San Jose, CA 95134 Phone: 978-288-7708 4295 Phone: 408-519-3986 Email: 4296 Email: travos@nortelnetworks.com 4297 cmonia@nishansystems.com 4299 David Robinson Wayland Jeong 4300 Sun Microsystems Troika Networks 4301 Senior Staff Engineer Vice President, Hardware 4302 M/S UNWK16-301 Engineering 4303 901 San Antonio Road 2829 Townsgate Road Suite 4304 Palo Alto, CA 94303-4900 200 4305 Phone: 510-936-2337 Westlake Village, CA 91361 4306 Email: Phone: 805-370-2614 4307 David.Robinson@sun.com Email: 4308 wayland@troikanetworks.com 4310 Rory Bolt Mark Edwards 4311 Quantum/ATL Senior Systems Architect 4312 Director, System Design Eurologic Development, Ltd. 4313 101 Innovation Drive 4th Floor, Howard House 4314 Irvine, CA 92612 Queens Ave, UK. BS8 1SD 4315 Phone: 949-856-7760 Phone: +44 (0)117 930 9600 4316 Email: rbolt@atlp.com Email: 4317 medwards@eurologic.com 4319 iFCP Revision 9 January 2002 4321 14. References 4323 14.1 Normative 4325 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 4326 3", BCP 9, RFC 2026, October 1996. 4328 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 4329 Requirement Levels", BCP 14, RFC 2119, March 1997 4331 [FC-FS] dpANS X3.XXX-200X, "Fibre Channel Framing and Signaling 4332 Interface", Revision 1.5, NCITS Project 1331-D, February 4333 2001 4335 [FC-SW2] dpANS X3.XXX-2000X, "Fibre Channel Switch Fabric -2 (FC- 4336 SW2)", revision 5.2, NCITS Project 1305-D, May 2001 4338 [FC-GS3] dpANS X3.XXX-200X, "Fibre Channel Generic Services -3 (FC- 4339 GS3)", revision 7.01, NCITS Project 1356-D, November 2000 4341 [RFC793] Postel, J., "Transmission Control Protocol", RFC 793, 4342 September, 1981 4344 [ENCAP] Weber, et-al., "FC Frame Encapsulation", draft-ietf-ips- 4345 fcencapsulation-01.txt, May 2001 4347 [ISNS] Tseng, J., et-al., "iSNS Internet Storage Name Service", 4348 draft-ietf-ips-04.txt, July 2001 4350 [RFC791] Postel, J., RFC 791, "The Internet Protocol", September 4351 1981 4353 [RFC2401] Kent, S., Atkinson, R., RFC 2401, "Security Architecture 4354 for the Internet Protocol", November 1998 4356 [RFC2402] Kent, S., Atkinson, R., RFC 2402, "IP Authentication 4357 Header", November 1998 4359 [RFC2404] Glenn, R., Madson, C., "The Use of HMAC-SHA-1-96 Within 4360 ESP and AH", RFC 2404, November 1998 4362 [RFC2406] Kent, S., Atkinson, R., RFC 2406, "Encapsulating Security 4363 Protocol", November 1998 4365 [RFC2407] Piper, D., RFC 2407, " The Internet IP Security Domain of 4366 Interpretation for ISAKMP", November 1998 4368 [RFC2408] Maughan, D., Schertler, M., Schneider, M., Turner, J., 4369 RFC 2408, "Internet Security Association and Key Management 4370 Protocol (ISAKMP)" November 1998 4372 iFCP Revision 9 January 2002 4374 [RFC2409] D. Harkins, D. Carrel, RFC 2409, "The Internet Key 4375 Exchange (IKE)", November 1998 4377 [RFC2410] Glenn, R., Kent, S., "The NULL Encryption Algorithm and 4378 Its use with IPSEC", RFC 2410, November 1998 4380 [RFC2451] Adams, R., Pereira, R., "The ESP CBC-Mode Cipher 4381 Algorithms", RFC 2451, November 1998 4383 [RFC2404] Glenn, R., Madson, C., "The Use of HMAC-SHA-1-96 Within 4384 ESP and AH", RFC 2404, November 1998 4386 [RFC2410] Glenn, R., Kent, S., "The NULL Encryption Algorithm and 4387 Its use with IPSEC", RFC 2410, November 1998 4389 [RFC2451] Adams, R., Pereira, R., "The ESP CBC-Mode Cipher 4390 Algorithms", RFC 2451, November 1998 4392 14.2 Non-Normative 4394 [KEMCMP] Kembel, R., "Fibre Channel, A Comprehensive Introduction", 4395 Northwest Learning Associates Inc., 2000, ISBN 0-931836-84- 4396 0 4398 [KEMAbLP] Kembel, R., "The Fibre Channel Consultant, Arbitrated 4399 Loop", Robert W. Kembel, Northwest Learning Associates, 4400 2000, ISBN 0-931836-84-0 4402 [FC-AL2] dpANS X3.XXX-199X, "Fibre Channel Arbitrated Loop (FC-AL- 4403 2)", revision 7.0, NCITS Project 1133D, April 1999 4405 [RFC896] Nagel, J., "Congestion Control in IP/TCP Networks", RFC 4406 896, January 1984 4408 [RFC2625] Rajagopal, M., et-al., RFC 2625, "IP and ARP over Fibre 4409 Channel", June 1999 4411 [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 4412 2131, March 1997 4414 [RFC2405] Doraswamy, N., Madson, C., "The ESP DES-CBC Cipher 4415 Algorithm With Explicit IV" RFC 2405, November 1998 4417 [RFC2030] Mills, D., RFC 2030, "Simple Network Time Protocol 4418 (SNTP)" Version 4, October 1996 4420 [RFC2709] Srisuresh, P., "Security Model with Tunnel-mode IPsec for 4421 NAT Domains", RFC 2709, October 1999 4423 [RFC2923] Lahey, K., "TCP Problems with Path MTU Discovery", RFC 4424 2923, September 2000 4426 iFCP Revision 9 January 2002 4428 [RFC1633] Braden, R., Clark, D. and S. Shenker, "Integrated 4429 Services in the Internet Architecture: an Overview", RFC 4430 1633, June 1994 4432 [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. 4433 and W. Weiss, "An Architecture for Differentiated 4434 Services", RFC 2475, December 1998 4436 [FC-FLA] TR-20-199X, "Fibre Channel Fabric Loop Attachment (FC- 4437 FLA)", revision 2.7, NCITS Project 1235-D, August 1997 4439 [RFC1122] Braden, S., "Requirements for Internet Hosts -- 4440 Communication Layers", RFC 1122, October 1989 4442 [RFC1323] Jacobsen, V., et-al., "TCP Extensions for High 4443 Performance", RFC 1323, May, 1992 4445 [AES] FIPS Publication XXX, "Advanced Encyption Standard (AES)", 4446 Draft, 2001, Available from 4447 http://csrc.nist.gov/publications/drafts/dfips-AES.pdf 4449 [XCBC] Black, J., Rogaway, P., "A Suggestion for Handling Arbitrary 4450 Length Messages with the CBC MAC". Available from 4451 http://csrc.nist.gov/encryption/modes/proposedmodes/xcbc- 4452 mac/xcbc-mac-spec.pdf 4454 [AESCTR] Lipmaa, H., Rogaway, P., Wagner, D., "CTR-Mode 4455 Encryption", 2001. Available from 4456 http://csrc.nist.gov/encryption/modes/proposedmodes/ctr/ctr 4457 -spec.pdf 4459 [RFC2405] Doraswamy, N., Madson, C., "The ESP DES-CBC Cipher 4460 Algorithm With Explicit IV" RFC 2405, November 1998 4462 [RFC3031] Rosen, E., Viswanathan, A. and Callon, R., "Multi- 4463 Protocol Label Switching Architecture", RFC 3031, January 4464 2001 4466 [MPSLDS] F. Faucheur, L. Wu, B. Davie, S. Davari, P. Vaananen, R. 4467 Krishnan, P. Cheval, J. Heinanen, "MPLS Support of 4468 Differentiated Services", draft-ietf-mpls-diff-ext-09.txt, 4469 April 2001. 4471 [DIFTERM] Grossman, D., "New Terminology and Clarifications for 4472 Diffserv", draft-ietf-diffserv-new-terms-07.txt, December 4473 2001 4475 iFCP Revision 9 January 2002 4477 Appendix A 4479 A. iFCP Support for Fibre Channel Link Services 4481 For reference purposes, this appendix enumerates all the Fibre 4482 Channel link services and the manner in which each shall be 4483 processed by an iFCP implementation. The iFCP processing policies 4484 are defined in section 8. 4486 In the following sections, the name of a link service specific to a 4487 particular FC-4 protocol is prefaced by a mnemonic identifying the 4488 protocol. 4490 A.1 Basic Link Services 4492 The basic link services are shown in the following table. 4494 Basic Link Services 4496 Name Description iFCP Policy 4497 ---- ----------- ---------- 4499 ABTS Abort Sequence Transparent 4500 BA_ACC Basic Accept Transparent 4501 BA_RJT Basic Reject Transparent 4502 NOP No Operation Transparent 4503 PRMT Preempted Rejected 4504 (Applies to 4505 Class 1 only) 4506 RMC Remove Connection Rejected 4507 (Applies to 4508 Class 1 only) 4510 A.2 Link Services Processed Transparently 4512 The following link service requests and responses MUST be processed 4513 transparently as defined in section 8. 4515 Link Services Processed Transparently 4517 Name Description 4518 ---- ----------- 4520 ACC Accept 4521 ADVC Advise Credit 4522 CSR Clock Synchronization Request 4523 CSU Clock Synchronization Update 4524 ECHO Echo 4525 ESTC Estimate Credit 4526 ESTS Establish Streaming 4527 FACT Fabric Activate Alias_ID 4529 iFCP Revision 9 January 2002 4531 FAN Fabric Address Notification 4532 FCP_RJT FCP FC-4 Link Service Reject 4533 FCP SRR FCP Sequence Retransmission Request 4534 FDACT Fabric Deactivate Alias_ID 4535 FDISC Discover F_Port Service Parameters 4536 FLOGI F_Port Login 4537 GAID Get Alias_ID 4538 LCLM Login Control List Management 4539 LINIT Loop Initialize 4540 LIRR Link Incident Record Registration 4541 LPC Loop Port Control 4542 LS_RJT Link Service Reject 4543 LSTS Loop Status 4544 NACT N_Port Activate Alias_ID 4545 NDACT N_Port Deactivate Alias_ID 4546 PDISC Discover N_Port Service Parameters 4547 PRLI Process Login 4548 PRLO Process Logout 4549 QoSR Quality of Service Request 4550 RCS Read Connection Status 4551 RLIR Registered Link Incident Report 4552 RNC Report Node Capability 4553 RNFT Report Node FC-4 Types 4554 RNID Request Node Identification Data 4555 RPL Read Port List 4556 RPS Read Port Status Block 4557 RPSC Report Port Speed Capabilities 4558 RSCN Registered State Change Notification 4559 RTV Read Timeout Value 4560 RVCS Read Virtual Circuit Status 4561 SBRP Set Bit-error Reporting Parameters 4562 SCL Scan Remote Loop 4563 SCN State Change Notification 4564 SCR State Change Registration 4565 TEST Test 4566 TPLS Test Process Login State 4568 A.3 iFCP-Processed Link Services 4570 The following extended and FC-4 link services are processed by the 4571 iFCP implementation as described in the referenced section listed 4572 in the table. 4574 Special Link Services 4576 Name Description Section 4577 ---- ----------- ------- 4579 ABTX Abort Exchange 8.3.1.1 4580 ADISC Discover Address 8.3.1.2 4581 ADISC ACC Discover Address Accept 8.3.1.3 4583 iFCP Revision 9 January 2002 4585 FARP-REPLY Fibre Channel Address 8.3.1.4 4586 Resolution Protocol Reply 4587 FARP-REQ Fibre Channel Address 8.3.1.5 4588 Resolution Protocol Request 4589 LOGO N_PORT Logout 8.3.1.6 4590 PLOGI Port Login 8.3.1.7 4591 FCP REC FCP Read Exchange Concise 8.3.2.1.1 4592 FCP REC ACC FCP Read Exchange Concise 8.3.2.1.2 4593 Accept 4594 RES Read Exchange Status Block 8.3.1.8 4595 RES ACC Read Exchange Status Block 8.3.1.9 4596 Accept 4597 RLS Read Link Error Status Block 8.3.1.10 4598 RRQ Reinstate Recovery Qualifier 8.3.1.12 4599 RSI Request Sequence Initiative 8.3.1.13 4600 RSS Read Sequence Status Block 8.3.1.11 4601 TPRLO Third Party Process Logout 8.3.1.14 4602 TPRLO ACC Third Party Process Logout 8.3.1.15 4603 Accept 4605 iFCP Revision 9 January 2002 4606 iFCP Revision 9 January 2002 4608 Full Copyright Statement 4610 "Copyright (C) The Internet Society, January 2002. All Rights 4611 Reserved. This document and translations of it may be copied and 4612 furnished to others, and derivative works that comment on or 4613 otherwise explain it or assist in its implmentation may be 4614 prepared, copied, published and distributed, in whole or in part, 4615 without restriction of any kind, provided that the above copyright 4616 notice and this paragraph are included on all such copies and 4617 derivative works. However, this document itself may not be modified 4618 in any way, such as by removing the copyright notice or references 4619 to the Internet Society or other Internet organizations, except as 4620 needed for the purpose of developing Internet standards in which 4621 case the procedures for copyrights defined in the Internet 4622 Standards process must be followed, or as required to translate it 4623 into languages other than English. 4625 The limited permissions granted above are perpetual and will not be 4626 revoked by the Internet Society or its successors or assigns. 4628 This document and the information contained herein is provided on 4629 an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET 4630 ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR 4631 IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 4632 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 4633 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE." 4635 iFCP Revision 9 January 2002