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Summary: 0 errors (**), 0 flaws (~~), 6 warnings (==), 5 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 Operations and Management Area Working Group T. Mizrahi 2 Internet Draft Marvell 3 Intended status: Informational N. Sprecher 4 Expires: April 2014 Nokia Siemens Networks 5 E. Bellagamba 6 Ericsson 7 Y. Weingarten 9 October 21, 2013 11 An Overview of Operations, Administration, and Maintenance (OAM) 12 Data Plane Tools 13 draft-ietf-opsawg-oam-overview-10.txt 15 Abstract 17 Operations, Administration, and Maintenance (OAM) is a general term 18 that refers to a toolset for fault detection and isolation, and for 19 performance measurement. Over the years various OAM tools have been 20 defined for various layers in the protocol stack. 22 This document summarizes some of the data plane OAM tools defined in 23 the IETF in the context of IP unicast, MPLS, pseudowires, MPLS for 24 the transport profile (MPLS-TP), and TRILL. 26 The target audience of this document includes network equipment 27 vendors, network operators and standard development organizations, 28 and can be used as an index to some of the main data plane OAM tools 29 defined in the IETF. 31 Status of this Memo 33 This Internet-Draft is submitted to IETF in full conformance with the 34 provisions of BCP 78 and BCP 79. 36 Internet-Drafts are working documents of the Internet Engineering 37 Task Force (IETF), its areas, and its working groups. Note that 38 other groups may also distribute working documents as Internet- 39 Drafts. 41 Internet-Drafts are draft documents valid for a maximum of six months 42 and may be updated, replaced, or obsoleted by other documents at any 43 time. It is inappropriate to use Internet-Drafts as reference 44 material or to cite them other than as "work in progress." 46 The list of current Internet-Drafts can be accessed at 47 http://www.ietf.org/ietf/1id-abstracts.txt. 49 The list of Internet-Draft Shadow Directories can be accessed at 50 http://www.ietf.org/shadow.html. 52 This Internet-Draft will expire on April 21, 2014. 54 Copyright Notice 56 Copyright (c) 2013 IETF Trust and the persons identified as the 57 document authors. All rights reserved. 59 This document is subject to BCP 78 and the IETF Trust's Legal 60 Provisions Relating to IETF Documents 61 (http://trustee.ietf.org/license-info) in effect on the date of 62 publication of this document. Please review these documents 63 carefully, as they describe your rights and restrictions with respect 64 to this document. Code Components extracted from this document must 65 include Simplified BSD License text as described in Section 4.e of 66 the Trust Legal Provisions and are provided without warranty as 67 described in the Simplified BSD License. 69 Table of Contents 71 1. Introduction ................................................. 3 72 1.1. Background .............................................. 4 73 1.2. Target Audience.......................................... 5 74 1.3. OAM-related Work in the IETF ............................ 5 75 1.4. Focusing on Data Plane OAM Tools ........................ 6 76 2. Terminology .................................................. 7 77 2.1. Abbreviations ........................................... 7 78 2.2. Terminology used in OAM Standards ....................... 9 79 2.2.1. General Terms ...................................... 9 80 2.2.2. Operations, Administration and Maintenance ......... 9 81 2.2.3. Functions, Tools and Protocols ..................... 9 82 2.2.4. Data Plane, Control Plane and Management Plane .... 10 83 2.2.5. The Players ....................................... 11 84 2.2.6. Proactive and On-demand Activation ................ 12 85 2.2.7. Connectivity Verification and Continuity Checks ... 12 86 2.2.8. Connection Oriented vs. Connectionless Communication13 87 2.2.9. Point-to-point vs. Point-to-multipoint Services ... 14 88 2.2.10. Failures ......................................... 14 89 3. OAM Functions ............................................... 15 90 4. OAM Tools in the IETF - a Detailed Description .............. 16 91 4.1. IP Ping ................................................ 16 92 4.2. IP Traceroute .......................................... 16 93 4.3. Bidirectional Forwarding Detection (BFD) ............... 17 94 4.3.1. Overview .......................................... 17 95 4.3.2. Terminology ....................................... 18 96 4.3.3. BFD Control ....................................... 18 97 4.3.4. BFD Echo .......................................... 18 98 4.4. MPLS OAM ............................................... 19 99 4.5. MPLS-TP OAM ............................................ 20 100 4.5.1. Overview .......................................... 20 101 4.5.2. Terminology ....................................... 20 102 4.5.3. Generic Associated Channel ........................ 22 103 4.5.4. MPLS-TP OAM Toolset ............................... 22 104 4.5.4.1. Continuity Check and Connectivity Verification 23 105 4.5.4.2. Route Tracing ................................ 23 106 4.5.4.3. Lock Instruct ................................ 23 107 4.5.4.4. Lock Reporting ............................... 24 108 4.5.4.5. Alarm Reporting .............................. 24 109 4.5.4.6. Remote Defect Indication ..................... 24 110 4.5.4.7. Client Failure Indication .................... 24 111 4.5.4.8. Performance Monitoring ....................... 24 112 4.5.4.8.1. Packet Loss Measurement (LM) ............ 24 113 4.5.4.8.2. Packet Delay Measurement (DM) ........... 25 114 4.6. Pseudowire OAM ......................................... 26 115 4.6.1. Pseudowire OAM using Virtual Circuit Connectivity 116 Verification (VCCV) ...................................... 26 117 4.6.2. Pseudowire OAM using G-ACh ........................ 27 118 4.6.3. Attachment Circuit - Pseudowire Mapping ........... 27 119 4.7. OWAMP and TWAMP......................................... 27 120 4.7.1. Overview .......................................... 27 121 4.7.2. Control and Test Protocols ........................ 28 122 4.7.3. OWAMP ............................................. 28 123 4.7.4. TWAMP ............................................. 29 124 4.8. TRILL .................................................. 29 125 4.9. Summary of OAM Tools ................................... 30 126 4.10. Summary of OAM Functions .............................. 32 127 5. Security Considerations ..................................... 33 128 6. IANA Considerations ......................................... 34 129 7. Acknowledgments ............................................. 34 130 8. References .................................................. 34 131 8.1. Informative References ................................. 34 132 Appendix A. List of OAM Documents .............................. 40 133 A.1. List of IETF OAM Documents ............................. 40 134 A.2. List of Selected Non-IETF OAM Documents ................ 44 136 1. Introduction 138 OAM is a general term that refers to a toolset for detecting, 139 isolating and reporting failures and for monitoring the network 140 performance. 142 There are several different interpretations to the "OAM" acronym. 143 This document refers to Operations, Administration and Maintenance, 144 as recommended in Section 3 of [RFC6291]. 146 This document summarizes some of the data plane OAM tools defined in 147 the IETF in the context of IP unicast, MPLS, pseudowires, MPLS for 148 the transport profile (MPLS-TP), and TRILL. 150 This document focuses on data plane OAM tools. Hence, control and 151 management aspects of OAM are outside the scope of this document. 152 This document focuses on tools for detecting and isolating failures 153 and for performance monitoring. Network repair functions such as Fast 154 Reroute (FRR) and protection switching, which are often triggered by 155 OAM protocols, are out of the scope of this document. 157 1.1. Background 159 OAM was originally used in traditional communication technologies 160 such as E1 and T1, evolving into PDH and then later in SONET/SDH. ATM 161 was probably the first technology to include inherent OAM support 162 from day one, while in other technologies OAM was typically defined 163 in an ad hoc manner after the technology was already defined and 164 deployed. Packet-based networks were traditionally considered 165 unreliable and best-effort, but as packet-based networks evolved, 166 they have become the common transport for both data and telephony, 167 replacing traditional transport protocols. Consequently, packet-based 168 networks were expected to provide a similar "carrier grade" 169 experience, and specifically to support OAM. 171 As typical networks have a multi-layer architecture, the set of OAM 172 protocols similarly take a multi-layer structure; each layer has its 173 own OAM protocols. Moreover, OAM can be used at different levels of 174 hierarchy in the network to form a multi-layer OAM solution, as shown 175 in the example in Figure 1. 177 Figure 1 illustrates a network in which IP traffic between two 178 customer edges is transported over an MPLS provider network. MPLS OAM 179 is used at the provider-level for monitoring the connection between 180 the two provider edges, while IP OAM is used at the customer-level 181 for monitoring the end-to-end connection between the two customer 182 edges. 184 |<-------------- Customer-level OAM -------------->| 185 IP OAM (Ping, Traceroute, OWAMP, TWAMP) 187 |<- Provider-level OAM ->| 188 MPLS OAM (LSP Ping) 190 +-----+ +----+ +----+ +-----+ 191 | | | |========================| | | | 192 | |-------| | MPLS | |-------| | 193 | | IP | | | | IP | | 194 +-----+ +----+ +----+ +-----+ 195 Customer Provider Provider Customer 196 Edge Edge Edge Edge 198 Figure 1 Example: Multi-layer OAM 200 1.2. Target Audience 202 The target audience of this document includes: 204 o Standard development organizations - both IETF working groups and 205 non-IETF organizations can benefit from this document when 206 designing new OAM protocols, or when looking to reuse existing OAM 207 tools for new technologies. 209 o Network equipment vendors and network operators - can use this 210 document as an index to some of the common IETF OAM tools. 212 It should be noted that this document is not necessarily suitable for 213 beginners without any background in OAM. 215 1.3. OAM-related Work in the IETF 217 This memo provides an overview of the different sets of OAM tools 218 defined by the IETF. The set of OAM tools described in this memo are 219 applicable to IP unicast, MPLS, pseudowires, MPLS for the transport 220 profile (MPLS-TP), and TRILL. While OAM tools that are applicable to 221 other technologies exist, they are beyond the scope of this memo. 223 This document focuses on IETF documents that have been published as 224 RFCs, while other ongoing OAM-related work is outside the scope. 226 The IETF has defined OAM protocols and tools in several different 227 contexts. We roughly categorize these efforts into a few sets of OAM- 228 related RFCs, listed in Table 1. Each category defines a logically- 229 coupled set of RFCs, although the sets are in some cases intertwined 230 by common tools and protocols. 232 The discussion in this document is ordered according to these 233 categories. 235 +--------------+------------+ 236 | Category | Transport | 237 | | Technology | 238 +--------------+------------+ 239 |IP Ping | IPv4/IPv6 | 240 +--------------+------------+ 241 |IP Traceroute | IPv4/IPv6 | 242 +--------------+------------+ 243 |BFD | generic | 244 +--------------+------------+ 245 |MPLS OAM | MPLS | 246 +--------------+------------+ 247 |MPLS-TP OAM | MPLS-TP | 248 +--------------+------------+ 249 |Pseudowire OAM| Pseudowires| 250 +--------------+------------+ 251 |OWAMP and | IPv4/IPv6 | 252 |TWAMP | | 253 +--------------+------------+ 254 |TRILL OAM | TRILL | 255 +--------------+------------+ 256 Table 1 Categories of OAM-related IETF Documents 258 1.4. Focusing on Data Plane OAM Tools 260 OAM tools may, and quite often do, work in conjunction with a control 261 plane and/or management plane. At the data plane, OAM provides 262 instrumentation tools. OAM tools often use control plane functions, 263 e.g., to initialize OAM sessions and to exchange various parameters. 264 The OAM tools communicate with the management plane to raise alarms, 265 and often OAM tools may be activated by the management (as well as by 266 the control plane), e.g. to locate and localize problems. 268 The considerations of the control plane maintenance tools and the 269 functionality of the management plane are out of scope for this 270 document, which concentrates on presenting the data plane tools that 271 are used for OAM. Network repair functions such as Fast Reroute (FRR) 272 and protection switching, which are often triggered by OAM protocols, 273 are also out of the scope of this document. 275 Since OAM protocols are used for monitoring the data plane, it is 276 imperative for OAM tools to be capable of testing the actual data 277 plane in as much accuracy as possible. Thus, it is important to 278 enforce fate-sharing between OAM traffic that monitors the data plane 279 and the data plane traffic it monitors. 281 2. Terminology 283 2.1. Abbreviations 285 ACH Associated Channel Header 287 AIS Alarm Indication Signal 289 ATM Asynchronous Transfer Mode 291 BFD Bidirectional Forwarding Detection 293 CC Continuity Check 295 CV Connectivity Verification 297 DM Delay Measurement 299 ECMP Equal Cost Multiple Paths 301 FEC Forwarding Equivalence Class 303 FRR Fast Reroute 305 G-ACh Generic Associated Channel 307 GAL Generic Associated Label 309 ICMP Internet Control Message Protocol 311 L2TP Layer Two Tunneling Protocol 313 LCCE L2TP Control Connection Endpoint 315 LDP Label Distribution Protocol 317 LER Label Edge Router 318 LM Loss Measurement 320 LSP Label Switched Path 322 LSR Label Switched Router 324 ME Maintenance Entity 326 MEG Maintenance Entity Group 328 MEP MEG End Point 330 MIP MEG Intermediate Point 332 MP Maintenance Point 334 MPLS Multiprotocol Label Switching 336 MPLS-TP MPLS Transport Profile 338 MTU Maximum Transmission Unit 340 OAM Operations, Administration, and Maintenance 342 PDH Plesiochronous Digital Hierarchy 344 PE Provider Edge 346 PW Pseudowire 348 PWE3 Pseudowire Emulation Edge-to-Edge 350 RBridge Routing Bridge 352 RDI Remote Defect Indication 354 SDH Synchronous Digital Hierarchy 356 SONET Synchronous Optical Networking 358 TRILL Transparent Interconnection of Lots of Links 360 TTL Time To Live 362 VCCV Virtual Circuit Connectivity Verification 364 2.2. Terminology used in OAM Standards 366 2.2.1. General Terms 368 A wide variety of terms is used in various OAM standards. This 369 section presents a comparison of the terms used in various OAM 370 standards, without fully quoting the definition of each term. 372 An interesting overview of the term OAM and its derivatives is 373 presented in [OAM-Def]. A thesaurus of terminology for MPLS-TP terms 374 is presented in [TP-Term], and provides a good summary of some of the 375 OAM related terminology. 377 2.2.2. Operations, Administration and Maintenance 379 The following definition of OAM is quoted from [OAM-Def]: 381 The components of the "OAM" acronym (and provisioning) are defined as 382 follows: 384 o Operations - Operation activities are undertaken to keep the 385 network (and the services that the network provides) up and 386 running. It includes monitoring the network and finding problems. 387 Ideally these problems should be found before users are affected. 389 o Administration - Administration activities involve keeping track 390 of resources in the network and how they are used. It includes 391 all the bookkeeping that is necessary to track networking 392 resources and the network under control. 394 o Maintenance - Maintenance activities are focused on facilitating 395 repairs and upgrades -- for example, when equipment must be 396 replaced, when a router needs a patch for an operating system 397 image, or when a new switch is added to a network. Maintenance 398 also involves corrective and preventive measures to make the 399 managed network run more effectively, e.g., adjusting device 400 configuration and parameters. 402 2.2.3. Functions, Tools and Protocols 404 OAM Function 406 An OAM function is an instrumentation measurement type or diagnostic. 408 OAM functions are the atomic building blocks of OAM, where each 409 function defines an OAM capability. 411 Typical examples of OAM functions are presented in Section 3. 413 OAM Protocol 415 A protocol used for implementing one or more OAM functions. 417 The OWAMP-Test [OWAMP] is an example of an OAM protocol. 419 OAM Tool 421 An OAM tool is a specific means of applying one or more OAM 422 functions. 424 In some cases an OAM protocol *is* an OAM tool, e.g., OWAMP-Test. In 425 other cases an OAM tool uses a set of protocols that are not strictly 426 OAM-related; for example, Traceroute (Section 4.2.) can be 427 implemented using UDP and ICMP messages, without using an OAM 428 protocol per se. 430 2.2.4. Data Plane, Control Plane and Management Plane 432 Data Plane 434 The data plane is the set of functions used to transfer data in the 435 stratum or layer under consideration [ITU-Terms]. 437 . 439 The Data Plane is also known as the Forwarding Plane or the User 440 Plane. 442 Control Plane 444 The control plane is the set of protocols and mechanisms that enable 445 routers to efficiently learn how to forward packets towards their 446 final destination (based on [Comp]). 448 Management Plane 450 The term Management Plane, as described in [Mng], is used to describe 451 the exchange of management messages through management protocols 452 (often transported by IP and by IP transport protocols) between 453 management applications and the managed entities such as network 454 nodes. 456 Data Plane vs. Control Plane vs. Management Plane 458 The distinction between the planes is at times a bit vague. For 459 example, the definition of "Control Plane" above may imply that OAM 460 tools such as ping, BFD and others are in fact in the control plane. 462 This document focuses on data plane OAM tools, i.e., tools used for 463 monitoring the data plane. While these tools could arguably be 464 considered to be in the control plane, these tools monitor the data 465 plane, and hence it is imperative to have fate-sharing between OAM 466 traffic that monitors the data plane and the data plane traffic it 467 monitors. 469 Another potentially vague distinction is between the management plane 470 and control plane. The management plane should be seen as separate 471 from, but possibly overlapping with, the control plane (based on 472 [Mng]). 474 2.2.5. The Players 476 An OAM tool is used between two (or more) "players". Various terms 477 are used in IETF documents to refer to the players that take part in 478 OAM. Table 2 summarizes the terms used in each of the categories 479 discussed in this document. 481 +--------------------------+--------------------------+ 482 | Category | Terms | 483 +--------------------------+--------------------------+ 484 | Ping / Traceroute |-Host | 485 | ([ICMPv4], [ICMPv6], |-Node | 486 | [TCPIP-Tools]) |-Interface | 487 | |-Gateway | 488 + ------------------------ + ------------------------ + 489 | BFD [BFD] | System | 490 + ------------------------ + ------------------------ + 491 | MPLS OAM [MPLS-OAM-FW] | LSR | 492 + ------------------------ + ------------------------ + 493 | MPLS-TP OAM [TP-OAM-FW] |-End Point - MEP | 494 | |-Intermediate Point - MIP | 495 + ------------------------ + ------------------------ + 496 | Pseudowire OAM [VCCV] |-PE | 497 | |-LCCE | 498 + ------------------------ + ------------------------ + 499 | OWAMP and TWAMP |-Host | 500 | ([OWAMP], [TWAMP]) |-End system | 501 + ------------------------ + ------------------------ + 502 | TRILL OAM [TRILL-OAM] |-RBridge | 503 +--------------------------+--------------------------+ 504 Table 2 Maintenance Point Terminology 506 2.2.6. Proactive and On-demand Activation 508 The different OAM tools may be used in one of two basic types of 509 activation: 511 Proactive 513 Proactive activation - indicates that the tool is activated on a 514 continual basis, where messages are sent periodically, and errors are 515 detected when a certain number of expected messages are not received. 517 On-demand 519 On-demand activation - indicates that the tool is activated 520 "manually" to detect a specific anomaly. 522 2.2.7. Connectivity Verification and Continuity Checks 524 Two distinct classes of failure management functions are used in OAM 525 protocols, connectivity verification and continuity checks. The 526 distinction between these terms is defined in [MPLS-TP-OAM], and is 527 used similarly in this document. 529 Continuity Check 531 Continuity checks are used to verify that a destination is reachable, 532 and are typically sent proactively, though they can be invoked on- 533 demand as well. 535 Connectivity Verification 537 A connectivity verification function allows Alice to check whether 538 she is connected to Bob or not. This function also allows Alice to 539 verify that messages from Bob are received through the correct path, 540 thereby verifying not only that the two MPs are connected, but also 541 that they are connected through the expected path, allowing detection 542 of unexpected topology changes. It is noted that while the CV 543 function is performed in the data plane, the "expected path" is 544 predetermined either in the control plane or in the management plane. 545 A connectivity verification (CV) protocol typically uses a CV 546 message, followed by a CV reply that is sent back to the originator. 547 A CV function can be applied proactively or on-demand. 549 Connectivity verification and continuity checks are considered 550 complementary mechanisms, and are often used in conjunction with each 551 other. 553 2.2.8. Connection Oriented vs. Connectionless Communication 555 Connection Oriented 557 In Connection Oriented technologies an end-to-end connection is 558 established (by a control protocol or provisioned by a management 559 system) prior to the transmission of data. 561 Typically a connection identifier is used to identify the connection. 562 In connection oriented technologies it is often the case (although 563 not always) that all packets belonging to a specific connection use 564 the same route through the network. 566 Connectionless 568 In Connectionless technologies data is typically sent between end 569 points without prior arrangement. Packets are routed independently 570 based on their destination address, and hence different packets may 571 be routed in a different way across the network. 573 Discussion 575 The OAM tools described in this document include tools that support 576 connection oriented technologies, as well as tools for connectionless 577 technologies. 579 In connection oriented technologies OAM is used to monitor a 580 *specific* connection; OAM packets are forwarded through the same 581 route as the data traffic and receive the same treatment. In 582 connectionless technologies, OAM is used between a source and 583 destination pair without defining a specific connection. Moreover, in 584 some cases the route of OAM packets may differ from the one of the 585 data traffic. For example, the connectionless IP Ping (Section 4.1.) 586 tests the reachability from a source to a given destination, while 587 the connection oriented LSP Ping (Section 4.4.) is used for 588 monitoring a specific LSP (connection), and provides the capability 589 to monitor all the available paths used by an LSP. 591 It should be noted that in some cases connectionless protocols are 592 monitored by connection oriented OAM protocols. For example, while IP 593 is a connectionless protocol, it can monitored by BFD (Section 4.3. 594 ), which is connection oriented. 596 2.2.9. Point-to-point vs. Point-to-multipoint Services 598 Point-to-point (P2P) 600 A P2P service delivers data from a single source to a single 601 destination. 603 Point-to-multipoint (P2MP) 605 An P2MP service delivers data from a single source to a one or more 606 destinations (based on [Signal]). 608 [Signal] also defines a MP2MP service as a service that delivers data 609 from more than one source to one or more receivers. 611 Discussion 613 The OAM tools described in this document include tools for P2P 614 services, as well as tools for P2MP services. 616 The distinction between P2P services and P2MP services affects the 617 corresponding OAM tools. A P2P service is typically simpler to 618 monitor, as it consists of a single pair of end points. P2MP services 619 present several challenges. For example, in a P2MP service, the OAM 620 mechanism not only verifies that each of the destinations is 621 reachable from the source, but also verifies that the P2MP 622 distribution tree is intact and loop-free. Another challenge in P2MP 623 services is performance monitoring; while in P2P packet loss is 624 measured by maintaining packet counters at the two end-points, in 625 P2MP packet loss must be carefully measured by generating synthetic 626 traffic to each corresponding end-point and maintaining a separate 627 counter for each peer end-point. 629 2.2.10. Failures 631 The terms Failure, Fault, and Defect are used interchangeably in the 632 standards, referring to a malfunction that can be detected by a 633 connectivity or a continuity check. In some standards, such as 634 802.1ag [IEEE802.1Q] , there is no distinction between these terms, 635 while in other standards each of these terms refers to a different 636 type of malfunction. 638 The terminology used in IETF MPLS-TP OAM is based on the ITU-T 639 terminology, which distinguishes between these three terms in 640 [ITU-T-G.806]; 642 Fault 644 The term Fault refers to an inability to perform a required action, 645 e.g., an unsuccessful attempt to deliver a packet. 647 Defect 649 The term Defect refers to an interruption in the normal operation, 650 such as a consecutive period of time where no packets are delivered 651 successfully. 653 Failure 655 The term Failure refers to the termination of the required function. 656 While a Defect typically refers to a limited period of time, a 657 failure refers to a long period of time. 659 3. OAM Functions 661 This subsection provides a brief summary of the common OAM functions 662 used in OAM-related standards. These functions are used as building 663 blocks in the OAM standards described in this document. 665 o Connectivity Verification (CV) and/or Continuity Checks (CC): 666 As defined in Section 2.2.7. 668 o Path Discovery / Fault Localization: 669 This function can be used to trace the route to a destination, 670 i.e., to identify the nodes along the route to the destination. 671 When more than one route is available to a specific destination, 672 this function traces one of the available routes. When a failure 673 occurs, this function also allows to detect the location of the 674 failure. 675 Note that the term route tracing (or Traceroute) that is used in 676 the context of IP and MPLS, is sometimes referred to as path 677 tracing in the context of other protocols, such as TRILL. 679 o Performance Monitoring: 680 Typically refers to: 682 o Loss Measurement (LM) - monitors the packet loss rate. 684 o Delay Measurement (DM) - monitors the delay and delay 685 variation. 687 4. OAM Tools in the IETF - a Detailed Description 689 This section presents a detailed description of the sets of OAM- 690 related tools in each of the categories in Table 1. 692 4.1. IP Ping 694 Ping is a common network diagnosis application for IP networks that 695 uses ICMP. According to [NetTerms], 'Ping' is an abbreviation for 696 Packet internet groper, although the term has been so commonly used 697 that it stands on its own. As defined in [NetTerms], it is a program 698 used to test reachability of destinations by sending them an ICMP 699 echo request and waiting for a reply. 701 The ICMP Echo request/reply exchange in Ping is used as a continuity 702 check function for the Internet Protocol. The originator transmits an 703 ICMP Echo request packet, and the receiver replies with an Echo 704 reply. ICMP ping is defined in two variants, [ICMPv4] is used for 705 IPv4, and [ICMPv6] is used for IPv6. 707 Ping implementations typically use ICMP messages. UDP Ping is a 708 variant that uses UDP messages instead of ICMP echo messages. 710 Ping is a single-ended continuity check, i.e., it allows the 711 *initiator* of the Echo request to test the reachability. If it is 712 desirable for both ends to test the reachability, both ends have to 713 invoke Ping independently. 715 Note that since ICMP filtering is deployed in some routers and 716 firewalls, the usefulness of Ping is sometimes limited in the wider 717 internet. This limitation is equally relevant to Traceroute. 719 4.2. IP Traceroute 721 Traceroute ([TCPIP-Tools], [NetTools]) is an application that allows 722 users to discover a path between an IP source and an IP destination. 724 The most common way to implement Traceroute [TCPIP-Tools] is 725 described as follows. Traceroute sends a sequence of UDP packets to 726 UDP port 33434 at the destination. By default, Traceroute begins by 727 sending three packets (the number of packets is configurable in most 728 Traceroute implementations), each with an IP Time-To-Live (or Hop 729 Limit in IPv6) value of one to the destination. These packets expire 730 as soon as they reach the first router in the path. Consequently, 731 that router sends three ICMP Time Exceeded Messages back to the 732 Traceroute application. Traceroute now sends another three UDP 733 packets, each with the TTL value of 2. These messages cause the 734 second router to return ICMP messages. This process continues, with 735 ever increasing values for the TTL field, until the packets actually 736 reach the destination. Because no application listens to port 33434 737 at the destination, the destination returns ICMP Destination 738 Unreachable Messages indicating an unreachable port. This event 739 indicates to the Traceroute application that it is finished. The 740 Traceroute program displays the round-trip delay associated with each 741 of the attempts. 743 While Traceroute is a tool that finds *a* path from A to B, it should 744 be noted that traffic from A to B is often forwarded through Equal 745 Cost Multiple Paths (ECMP). Paris Traceroute [Paris] is an extension 746 to Traceroute that attempts to discovers all the available paths from 747 A to B by scanning different values of header fields (such as UDP 748 ports) in the probe packets. 750 It is noted that Traceroute is an application, and not a protocol. As 751 such, it has various different implementations. One of the most 752 common ones uses UDP probe packets, as described above. Other 753 implementations exist that use other types of probe messages, such as 754 ICMP or TCP. 756 Note that IP routing may be asymmetric. While Traceroute discovers a 757 path between a source and destination, it does not reveal the reverse 758 path. 760 A few ICMP extensions ([ICMP-MP], [ICMP-Int]) have been defined in 761 the context of Traceroute. These documents define several extensions, 762 including extensions to the ICMP Destination Unreachable message, 763 that can be used by Traceroute applications. 765 4.3. Bidirectional Forwarding Detection (BFD) 767 4.3.1. Overview 769 While multiple OAM tools have been defined for various protocols in 770 the protocol stack, Bidirectional Forwarding Detection [BFD], defined 771 by the IETF BFD working group, is a generic OAM tool that can be 772 deployed over various encapsulating protocols, and in various medium 773 types. The IETF has defined variants of the protocol for IP ([BFD- 774 IP], [BFD-Multi]), for MPLS LSPs [BFD-LSP], and for pseudowires [BFD- 775 VCCV]. The usage of BFD in MPLS-TP is defined in [TP-CC-CV]. 777 BFD includes two main OAM functions, using two types of BFD packets: 778 BFD Control packets, and BFD Echo packets. 780 4.3.2. Terminology 782 BFD operates between two *systems*. The BFD protocol is run between 783 two systems after establishing a *session*. 785 4.3.3. BFD Control 787 BFD supports a bidirectional continuity check, using BFD control 788 packets, that are exchanged within a BFD session. BFD sessions 789 operate in one of two modes: 791 o Asynchronous mode (i.e. proactive): in this mode BFD control 792 packets are sent periodically. When the receiver detects that no 793 BFD control packets have been received during a predetermined 794 period of time, a failure is detected. 796 o Demand mode: in this mode, BFD control packets are sent on-demand. 797 Upon need, a system initiates a series of BFD control packets to 798 check the continuity of the session. BFD control packets are sent 799 independently in each direction. 801 Each of the end-points (referred to as systems) of the monitored path 802 maintains its own session identification, called a Discriminator, 803 both of which are included in the BFD Control Packets that are 804 exchanged between the end-points. At the time of session 805 establishment, the Discriminators are exchanged between the two-end 806 points. In addition, the transmission (and reception) rate is 807 negotiated between the two end-points, based on information included 808 in the control packets. These transmission rates may be renegotiated 809 during the session. 811 During normal operation of the session, i.e. no failures are 812 detected, the BFD session is in the Up state. If no BFD Control 813 packets are received during a period of time called the Detection 814 Time, the session is declared to be Down. The detection time is a 815 function of the pre-configured or negotiated transmission time, and a 816 parameter called Detect Mult. Detect Mult determines the number of 817 missing BFD Control packets that cause the session to be declared as 818 Down. This parameter is included in the BFD Control packet. 820 4.3.4. BFD Echo 822 A BFD echo packet is sent to a peer system, and is looped back to the 823 originator. The echo function can be used proactively, or on-demand. 825 The BFD echo function has been defined in BFD for IPv4 and IPv6 826 ([BFD-IP]), but is not used in BFD for MPLS LSPs, PWs, or in BFD for 827 MPLS-TP. 829 4.4. MPLS OAM 831 The IETF MPLS working group has defined OAM for MPLS LSPs. The 832 requirements and framework of this effort are defined in 833 [MPLS-OAM-FW] and [MPLS-OAM], respectively. The corresponding OAM 834 tool defined, in this context, is LSP Ping [LSP-Ping]. OAM for P2MP 835 services is defined in [MPLS-P2MP]. 837 LSP Ping is modeled after the Ping/Traceroute paradigm and thus it 838 may be used in one of two modes: 840 o "Ping" mode: In this mode LSP Ping is used for end-to-end 841 connectivity verification between two LERs. 843 o "Traceroute" mode: This mode is used for hop-by-hop fault 844 isolation. 846 LSP Ping extends the basic ICMP Ping operation (of data-plane 847 connectivity verification) with functionality to verify data-plane 848 vs. control-plane consistency for a Forwarding Equivalence Class 849 (FEC) and also Maximum Transmission Unit (MTU) problems. 851 The challenge in MPLS networks is that the traffic of a given LSP may 852 be load balanced across Equal Cost Multiple paths (ECMP). LSP Ping 853 monitors all the available paths of an LSP by monitoring its 854 different Forwarding Equivalence Classes (FEC). Conversely, MPLS-TP 855 does not use ECMP, and thus does not require OAM over multiple paths. 856 The Traceroute functionality may be used to isolate and localize the 857 MPLS faults, using the Time-to-live (TTL) indicator to incrementally 858 identify the sub-path of the LSP that is successfully traversed 859 before the faulty link or node. 861 It should be noted that LSP Ping supports unique identification of 862 the LSP within an addressing domain. The identification is checked 863 using the full FEC identification. LSP Ping is easily extensible to 864 include additional information needed to support new functionality, 865 by use of Type-Length-Value (TLV) constructs. The usage of TLVs is 866 typically not easy to perform in hardware, and is thus typically 867 handled by the control plane. 869 LSP Ping supports both asynchronous, as well as, on-demand 870 activation. 872 4.5. MPLS-TP OAM 874 4.5.1. Overview 876 The MPLS working group has defined the OAM toolset that fulfills the 877 requirements for MPLS-TP OAM. The full set of requirements for MPLS- 878 TP OAM are defined in [MPLS-TP-OAM], and include both general 879 requirements for the behavior of the OAM tools and a set of 880 operations that should be supported by the OAM toolset. The set of 881 mechanisms required are further elaborated in [TP-OAM-FW], which 882 describes the general architecture of the OAM system as well as 883 giving overviews of the functionality of the OAM toolset. 885 Some of the basic requirements for the OAM toolset for MPLS-TP are: 887 o MPLS-TP OAM must be able to support both an IP based and non-IP 888 based environment. If the network is IP based, i.e. IP routing and 889 forwarding are available, then the MPLS-TP OAM toolset should rely 890 on the IP routing and forwarding capabilities. On the other hand, 891 in environments where IP functionality is not available, the OAM 892 tools must still be able to operate without dependence on IP 893 forwarding and routing. 895 o OAM packets and the user traffic are required to be congruent 896 (i.e. OAM packets are transmitted in-band) and there is a need to 897 differentiate OAM packets from data plane ones. Inherent in this 898 requirement is the principle that MPLS-TP OAM be independent of 899 any existing control-plane, although it should not preclude use of 900 the control-plane functionality. 902 4.5.2. Terminology 904 Maintenance Entity (ME) 906 The MPLS-TP OAM tools are designed to monitor and manage a 907 Maintenance Entity (ME). An ME, as defined in [TP-OAM-FW], defines a 908 relationship between two points of a transport path to which 909 maintenance and monitoring operations apply. 911 The term Maintenance Entity (ME) is used in ITU-T Recommendations 912 (e.g. [ITU-T-Y1731]), as well as in the MPLS-TP terminology 913 ([TP-OAM-FW]). 915 Maintenance Entity Group (MEG) 916 The collection of one or more MEs that belongs to the same transport 917 path and that are maintained and monitored as a group are known as a 918 Maintenance Entity Group (based on [TP-OAM-FW]). 920 Maintenance Point (MP) 922 A Maintenance Point (MP) is a functional entity that is defined at a 923 node in the network, and can initiate and/or react to OAM messages. 924 This document focuses on the data-plane functionality of MPs, while 925 MPs interact with the control plane and with the management plane as 926 well. 928 The term MP is used in IEEE 802.1ag, and was similarly adopted in 929 MPLS-TP ([TP-OAM-FW]). 931 Maintenance End Point (MEP) 933 A Maintenance End Point (MEP) is one of the end points of an ME, and 934 can initiate OAM messages and respond to them (based on [TP-OAM-FW]). 936 Maintenance Intermediate Point (MIP) 938 In between MEPs, there are zero or more intermediate points, called 939 Maintenance Entity Group Intermediate Points (based on [TP-OAM-FW]). 941 A Maintenance Intermediate Point (MIP) is an intermediate point that 942 does not generally initiate OAM frames (one exception to this is the 943 use of AIS notifications), but is able to respond to OAM frames that 944 are destined to it. A MIP in MPLS-TP identifies OAM packets destined 945 to it by the value of the TTL field in the OAM packet. The term 946 Maintenance Point is a general term for MEPs and MIPs. 948 Up and Down MEPs 950 The IEEE 802.1ag [IEEE802.1Q] defines a distinction between Up MEPs 951 and Down MEPs. A MEP is a bridge interface that is monitored by an 952 OAM protocol either in the direction facing the network, or in the 953 direction facing the bridge. A Down MEP is a MEP that receives OAM 954 packets from, and transmits them to the direction of the network. An 955 Up MEP receives OAM packets from, and transmits them to the direction 956 of the bridging entity. MPLS-TP ([TP-OAM-FW]) uses a similar 957 distinction on the placement of the MEP - either at the ingress, 958 egress, or forwarding function of the node (Down / Up MEPs). This 959 placement is important for localization of a failure. 961 The distinction between Up and Down MEPs was defined in [TP-OAM-FW], 962 but has not been used in other MPLS-TP RFCs, as of the writing of 963 this document. 965 4.5.3. Generic Associated Channel 967 In order to address the requirement for in-band transmission of MPLS- 968 TP OAM traffic, MPLS-TP uses a Generic Associated Channel (G-ACh), 969 defined in [G-ACh] for LSP-based OAM traffic. This mechanism is based 970 on the same concepts as the PWE3 ACH and VCCV mechanisms. However, 971 to address the needs of LSPs as differentiated from PW, the following 972 concepts were defined for [G-ACh]: 974 o An Associated Channel Header (ACH), that uses a format similar to 975 the PW Control Word, is a 4-byte header that is prepended to OAM 976 packets. 978 o A Generic Associated Label (GAL). The GAL is a reserved MPLS label 979 value (13) that indicates that the packet is an ACH packet and the 980 payload follows immediately after the label stack. 982 It should be noted that while the G-ACh was defined as part of the 983 MPLS-TP definition effort, the G-ACh is a generic tool that can be 984 used in MPLS in general, and not only in MPLS-TP. 986 4.5.4. MPLS-TP OAM Toolset 988 To address the functionality that is required of the OAM toolset, the 989 MPLS WG conducted an analysis of the existing IETF and ITU-T OAM 990 tools and their ability to fulfill the required functionality. The 991 conclusions of this analysis are documented in [OAM-Analys]. The MPLS 992 working group currently plans to use a mixture of OAM tools that are 993 based on various existing standards, and adapt them to the 994 requirements of [MPLS-TP-OAM]. Some of the main building blocks of 995 this solution are based on: 997 o Bidirectional Forwarding Detection ([BFD], [BFD-LSP]) for 998 proactive continuity check and connectivity verification. 1000 o LSP Ping as defined in [LSP-Ping] for on-demand connectivity 1001 verification. 1003 o New protocol packets, using G-ACH, to address different 1004 functionality. 1006 o Performance measurement protocols that are based on the 1007 functionality that is described in [ITU-T-Y1731]. 1009 The following sub-sections describe the OAM tools defined for MPLS-TP 1010 as described in [TP-OAM-FW]. 1012 4.5.4.1. Continuity Check and Connectivity Verification 1014 Continuity Check and Connectivity Verification are presented in 1015 Section 2.2.7. of this document. As presented there, these tools may 1016 be used either proactively or on-demand. When using these tools 1017 proactively, they are generally used in tandem. 1019 For MPLS-TP there are two distinct tools, the proactive tool is 1020 defined in [TP-CC-CV] while the on-demand tool is defined in 1021 [OnDemand-CV]. In on-demand mode, this function should support 1022 monitoring between the MEPs and, in addition, between a MEP and MIP. 1023 [TP-OAM-FW] highlights, when performing Connectivity Verification, 1024 the need for the CC-V messages to include unique identification of 1025 the MEG that is being monitored and the MEP that originated the 1026 message. 1028 The proactive tool [TP-CC-CV] is based on extensions to BFD (see 1029 Section 4.3.) with the additional limitation that the transmission 1030 and receiving rates are based on configuration by the operator. The 1031 on-demand tool [OnDemand-CV] is an adaptation of LSP Ping (see 1032 Section 4.4.) for the required behavior of MPLS-TP. 1034 4.5.4.2. Route Tracing 1036 [MPLS-TP-OAM] defines that there is a need for functionality that 1037 would allow a path end-point to identify the intermediate and end- 1038 points of the path. This function would be used in on-demand mode. 1039 Normally, this path will be used for bidirectional PW, LSP, and 1040 sections, however, unidirectional paths may be supported only if a 1041 return path exists. The tool for this is based on the LSP Ping (see 1042 Section 4.4.) functionality and is described in [OnDemand-CV]. 1044 4.5.4.3. Lock Instruct 1046 The Lock Instruct function [Lock-Loop] is used to notify a transport 1047 path end-point of an administrative need to disable the transport 1048 path. This functionality will generally be used in conjunction with 1049 some intrusive OAM function, e.g. Performance measurement, Diagnostic 1050 testing, to minimize the side-effect on user data traffic. 1052 4.5.4.4. Lock Reporting 1054 Lock Reporting is a function used by an end-point of a path to report 1055 to its far-end end-point that a lock condition has been affected on 1056 the path. 1058 4.5.4.5. Alarm Reporting 1060 Alarm Reporting [TP-Fault] provides the means to suppress alarms 1061 following detection of defect conditions at the server sub-layer. 1062 Alarm reporting is used by an intermediate point of a path, that 1063 becomes aware of a fault on the path, to report to the end-points of 1064 the path. [TP-OAM-FW] states that this may occur as a result of a 1065 defect condition discovered at a server sub-layer. This generates an 1066 Alarm Indication Signal (AIS) that continues until the fault is 1067 cleared. The consequent action of this function is detailed in 1068 [TP-OAM-FW]. 1070 4.5.4.6. Remote Defect Indication 1072 Remote Defect Indication (RDI) is used proactively by a path end- 1073 point to report to its peer end-point that a defect is detected on a 1074 bidirectional connection between them. [MPLS-TP-OAM] points out that 1075 this function may be applied to a unidirectional LSP only if there a 1076 return path exists. [TP-OAM-FW] points out that this function is 1077 associated with the proactive CC-V function. 1079 4.5.4.7. Client Failure Indication 1081 Client Failure Indication (CFI) is defined in [MPLS-TP-OAM] to allow 1082 the propagation information from one edge of the network to the 1083 other. The information concerns a defect to a client, in the case 1084 that the client does not support alarm notification. 1086 4.5.4.8. Performance Monitoring 1088 The definition of MPLS performance monitoring was motivated by the 1089 MPLS-TP requirements [MPLS-TP-OAM], but was defined generically for 1090 MPLS in [MPLS-LM-DM]. An additional document [TP-LM-DM] defines a 1091 performance monitoring profile for MPLS-TP. 1093 4.5.4.8.1. Packet Loss Measurement (LM) 1095 Packet Loss Measurement is a function used to verify the quality of 1096 the service. Packet loss, as defined in [IPPM-1LM] and [MPLS-TP-OAM], 1097 indicates the ratio of the number of user packets lost to the total 1098 number of user packets sent during a defined time interval. 1100 There are two possible ways of determining this measurement: 1102 o Using OAM packets, it is possible to compute the statistics based 1103 on a series of OAM packets. This, however, has the disadvantage of 1104 being artificial, and may not be representative since part of the 1105 packet loss may be dependent upon packet sizes and upon the 1106 implementation of the MEPs that take part in the protocol. 1108 o Sending delimiting messages for the start and end of a measurement 1109 period during which the source and sink of the path count the 1110 packets transmitted and received. After the end delimiter, the 1111 ratio would be calculated by the path OAM entity. 1113 4.5.4.8.2. Packet Delay Measurement (DM) 1115 Packet Delay Measurement is a function that is used to measure one- 1116 way or two-way delay of a packet transmission between a pair of the 1117 end-points of a path (PW, LSP, or Section). Where: 1119 o One-way packet delay, as defined in [IPPM-1DM], is the time 1120 elapsed from the start of transmission of the first bit of the 1121 packet by a source node until the reception of the last bit of 1122 that packet by the destination node. Note that one-way delay 1123 measurement requires the clocks of the two end-points to be 1124 synchronized. 1126 o Two-way packet delay, as defined in [IPPM-2DM], is the time 1127 elapsed from the start of transmission of the first bit of the 1128 packet by a source node until the reception of the last bit of the 1129 loop-backed packet by the same source node, when the loopback is 1130 performed at the packet's destination node. Note that due to 1131 possible path asymmetry, the one-way packet delay from one end- 1132 point to another is not necessarily equal to half of the two-way 1133 packet delay. 1134 As opposed to one-way delay measurement, two-way delay measurement 1135 does not require the two end-points to be synchronized. 1137 For each of these two metrics, the DM function allows the MEP to 1138 measure the delay, as well as the delay variation. Delay measurement 1139 is performed by exchanging timestamped OAM packets between the 1140 participating MEPs. 1142 4.6. Pseudowire OAM 1144 4.6.1. Pseudowire OAM using Virtual Circuit Connectivity Verification 1145 (VCCV) 1147 VCCV, as defined in [VCCV], provides a means for end-to-end fault 1148 detection and diagnostics tools to be extended for PWs (regardless of 1149 the underlying tunneling technology). The VCCV switching function 1150 provides a control channel associated with each PW. [VCCV] defines 1151 three Control Channel (CC) types, i.e., three possible methods for 1152 transmitting and identifying OAM messages: 1154 o CC Type 1: In-band VCCV, as described in [VCCV], is also referred 1155 to as "PWE3 Control Word with 0001b as first nibble". It uses the 1156 PW Associated Channel Header [PW-ACH]. 1158 o CC Type 2: Out-of-band VCCV [VCCV], is also referred to as "MPLS 1159 Router Alert Label". In this case the control channel is created 1160 by using the MPLS router alert label [RFC3032] immediately above 1161 the PW label. 1163 o CC Type 3: TTL expiry VCCV [VCCV], is also referred to as "MPLS PW 1164 Label with TTL == 1", i.e., the control channel is identified when 1165 the value of the TTL field in the PW label is set to 1. 1167 VCCV currently supports the following OAM tools: ICMP Ping, LSP Ping, 1168 and BFD. ICMP and LSP Ping are IP encapsulated before being sent over 1169 the PW ACH. BFD for VCCV [BFD-VCCV] supports two modes of 1170 encapsulation - either IP/UDP encapsulated (with IP/UDP header) or 1171 PW-ACH encapsulated (with no IP/UDP header) and provides support to 1172 signal the AC status. The use of the VCCV control channel provides 1173 the context, based on the MPLS-PW label, required to bind and 1174 bootstrap the BFD session to a particular pseudo wire (FEC), 1175 eliminating the need to exchange Discriminator values. 1177 VCCV consists of two components: (1) signaled component to 1178 communicate VCCV capabilities as part of VC label, and (2) switching 1179 component to cause the PW payload to be treated as a control packet. 1181 VCCV is not directly dependent upon the presence of a control plane. 1182 The VCCV capability negotiation may be performed as part of the PW 1183 signaling when LDP is used. In case of manual configuration of the 1184 PW, it is the responsibility of the operator to set consistent 1185 options at both ends. The manual option was created specifically to 1186 handle MPLS-TP use cases where no control plane was a requirement. 1187 However, new use cases such as pure mobile backhaul find this 1188 functionality useful too. 1190 The PWE3 working group has conducted an implementation survey of VCCV 1191 [VCCV-SURVEY], which analyzes which VCCV mechanisms are used in 1192 practice. 1194 4.6.2. Pseudowire OAM using G-ACh 1196 As mentioned above, VCCV enables OAM for PWs by using a control 1197 channel for OAM packets. When PWs are used in MPLS-TP networks, 1198 rather than the control channels defined in VCCV, the G-ACh can be 1199 used as an alternative control channel. The usage of the G-ACh for 1200 PWs is defined in [PW-G-ACh]. 1202 4.6.3. Attachment Circuit - Pseudowire Mapping 1204 The PWE3 working group has defined a mapping and notification of 1205 defect states between a pseudowire (PW) and the Attachment Circuits 1206 (ACs) of the end-to-end emulated service. This mapping is of key 1207 importance to the end-to-end functionality. Specifically, the mapping 1208 is provided by [PW-MAP], by [L2TP-EC] for L2TPv3 pseudowires, and 1209 Section 5.3 of [ATM-L2] for ATM. 1211 4.7. OWAMP and TWAMP 1213 4.7.1. Overview 1215 The IPPM working group in the IETF defines common criteria and 1216 metrics for measuring performance of IP traffic ([IPPM-FW]). Some of 1217 the key RFCs published by this working group have defined metrics for 1218 measuring connectivity [IPPM-Con], delay ([IPPM-1DM], [IPPM-2DM]), 1219 and packet loss [IPPM-1LM]. It should be noted that the work of the 1220 IETF in the context of performance metrics is not limited to IP 1221 networks; [PM-CONS] presents general guidelines for considering new 1222 performance metrics. 1224 The IPPM working group has defined not only metrics for performance 1225 measurement, but also protocols that define how the measurement is 1226 carried out. The One-way Active Measurement Protocol [OWAMP] and the 1227 Two-Way Active Measurement Protocol [TWAMP] define a method and 1228 protocol for measuring performance metrics in IP networks. 1230 OWAMP [OWAMP] enables measurement of one-way characteristics of IP 1231 networks, such as one-way packet loss and one-way delay. For its 1232 proper operation OWAMP requires accurate time of day setting at its 1233 end points. 1235 TWAMP [TWAMP] is a similar protocol that enables measurement of both 1236 one-way and two-way (round trip) characteristics. 1238 OWAMP and TWAMP are both comprised of two separate protocols: 1240 o OWAMP-Control/TWAMP-Control: used to initiate, start, and stop 1241 test sessions and to fetch their results. Continuity Check and 1242 Connectivity Verification are tested and confirmed by establishing 1243 the OWAMP/TWAMP Control Protocol TCP connection. 1245 o OWAMP-Test/TWAMP-Test: used to exchange test packets between two 1246 measurement nodes. Enables the loss and delay measurement 1247 functions, as well as detection of other anomalies, such as packet 1248 duplication and packet reordering. 1250 It should be noted that while [OWAMP] and [TWAMP] define tools for 1251 performance measurement, they do not define the accuracy of these 1252 tools. The accuracy depends on scale, implementation and network 1253 configurations. 1255 Alternative protocols for performance monitoring are defined, for 1256 example, in MPLS-TP OAM ([MPLS-LM-DM], [TP-LM-DM]), and in Ethernet 1257 OAM [ITU-T-Y1731]. 1259 4.7.2. Control and Test Protocols 1261 OWAMP and TWAMP control protocols run over TCP, while the test 1262 protocols run over UDP. The purpose of the control protocols is to 1263 initiate, start, and stop test sessions, and for OWAMP to fetch 1264 results. The test protocols introduce test packets (which contain 1265 sequence numbers and timestamps) along the IP path under test 1266 according to a schedule, and record statistics of packet arrival. 1267 Multiple sessions may be simultaneously defined, each with a session 1268 identifier, and defining the number of packets to be sent, the amount 1269 of padding to be added (and thus the packet size), the start time, 1270 and the send schedule (which can be either a constant time between 1271 test packets or exponentially distributed pseudo-random). Statistics 1272 recorded conform to the relevant IPPM RFCs. 1274 OWAMP and TWAMP test traffic is designed with security in mind. Test 1275 packets are hard to detect because they are simply UDP streams 1276 between negotiated port numbers, with potentially nothing static in 1277 the packets. OWAMP and TWAMP also include optional authentication 1278 and encryption for both control and test packets. 1280 4.7.3. OWAMP 1282 OWAMP defines the following logical roles: Session-Sender, Session- 1283 Receiver, Server, Control-Client, and Fetch-Client. The Session- 1284 Sender originates test traffic that is received by the Session- 1285 Receiver. The Server configures and manages the session, as well as 1286 returning the results. The Control-Client initiates requests for 1287 test sessions, triggers their start, and may trigger their 1288 termination. The Fetch-Client requests the results of a completed 1289 session. Multiple roles may be combined in a single host - for 1290 example, one host may play the roles of Control-Client, Fetch-Client, 1291 and Session-Sender, and a second playing the roles of Server and 1292 Session-Receiver. 1294 In a typical OWAMP session the Control-Client establishes a TCP 1295 connection to port 861 of the Server, which responds with a server 1296 greeting message indicating supported security/integrity modes. The 1297 Control-Client responds with the chosen communications mode and the 1298 Server accepts the modes. The Control-Client then requests and fully 1299 describes a test session to which the Server responds with its 1300 acceptance and supporting information. More than one test session 1301 may be requested with additional messages. The Control-Client then 1302 starts a test session and the Server acknowledges. The Session- 1303 Sender then sends test packets with pseudorandom padding to the 1304 Session-Receiver until the session is complete or until the Control- 1305 client stops the session. Once finished, the Fetch-Client sends a 1306 fetch request to the server, which responds with an acknowledgement 1307 and immediately thereafter the result data. 1309 4.7.4. TWAMP 1311 TWAMP defines the following logical roles: session-sender, session- 1312 reflector, server, and control-client. These are similar to the 1313 OWAMP roles, except that the Session-Reflector does not collect any 1314 packet information, and there is no need for a Fetch-Client. 1316 In a typical TWAMP session the Control-Client establishes a TCP 1317 connection to port 862 of the Server, and mode is negotiated as in 1318 OWAMP. The Control-Client then requests sessions and starts them. 1319 The Session-Sender sends test packets with pseudorandom padding to 1320 the Session-Reflector which returns them with insertion of 1321 timestamps. 1323 4.8. TRILL 1325 The requirements of OAM in TRILL are defined in [TRILL-OAM]. The 1326 challenge in TRILL OAM, much like in MPLS networks, is that traffic 1327 between RBridges RB1 and RB2 may be forwarded through more than one 1328 path. Thus, an OAM protocol between RBridges RB1 and RB2 must be able 1329 to monitor all the available paths between the two RBridge. 1331 During the writing of this document the detailed definition of the 1332 TRILL OAM tools are still work in progress. This subsection presents 1333 the main requirements of TRILL OAM. 1335 The main requirements defined in [TRILL-OAM] are: 1337 o Continuity Checking (CC) - the TRILL OAM protocol must support a 1338 function for CC between any two RBridges RB1 and RB2. 1340 o Connectivity Verification (CV) - connectivity between two RBridges 1341 RB1 and RB2 can be verified on a per-flow basis. 1343 o Path Tracing - allows an RBridge to trace all the available paths 1344 to a peer RBridge. 1346 o Performance monitoring - allows an RBridge to monitor the packet 1347 loss and packet delay to a peer RBridge. 1349 4.9. Summary of OAM Tools 1351 This subsection provides a short summary of each of the OAM tool 1352 categories described in this document. 1354 A detailed list of the RFCs related to each category is given in 1355 Appendix A.1. 1357 +-----------+------------------------------------------+------------+ 1358 | Category | Description | Transport | 1359 | | | Technology | 1360 +-----------+------------------------------------------+------------+ 1361 |IP Ping | Ping ([IntHost], [NetTerms]) is a simple | IPv4/IPv6 | 1362 | | application for testing reachability that| | 1363 | | uses ICMP Echo messages ([ICMPv4], | | 1364 | | [ICMPv6]). | | 1365 +-----------+------------------------------------------+------------+ 1366 |IP | Traceroute ([TCPIP-Tools], [NetTools]) is| IPv4/IPv6 | 1367 |Traceroute | an application that allows users to trace| | 1368 | | the path between an IP source and an IP | | 1369 | | destination, i.e., to identify the nodes | | 1370 | | along the path. If more than one path | | 1371 | | exists between the source and destination| | 1372 | | Traceroute traces *a* path. The most | | 1373 | | common implementation of Traceroute | | 1374 | | uses UDP probe messages, although there | | 1375 | | are other implementations that use | | 1376 | | different probes, such as ICMP or TCP. | | 1377 +-----------+------------------------------------------+------------+ 1378 |BFD | Bidirectional Forwarding Detection (BFD) | generic | 1379 | | is defined in [BFD] as a framework for a | | 1380 | | lightweight generic OAM tool. The | | 1381 | | intention is to define a base tool | | 1382 | | that can be used with various | | 1383 | | encapsulation types, network | | 1384 | | environments, and in various medium | | 1385 | | types. | | 1386 +-----------+------------------------------------------+------------+ 1387 |MPLS OAM | MPLS LSP Ping, as defined in [MPLS-OAM], | MPLS | 1388 | | [MPLS-OAM-FW] and [LSP-Ping], is an OAM | | 1389 | | tool for point-to-point and | | 1390 | | point-to-multipoint MLPS LSPs. | | 1391 | | It includes two main functions: Ping and | | 1392 | | Traceroute. | | 1393 | | It is noted that while this category | | 1394 | | focuses on LSP Ping, other OAM tools | | 1395 | | can be used in MPLS networks, e.g., BFD. | | 1396 +-----------+------------------------------------------+------------+ 1397 |MPLS-TP OAM| MPLS-TP OAM is defined in a set of RFCs. | MPLS-TP | 1398 | | The OAM requirements for MPLS Transport | | 1399 | | Profile (MPLS-TP) are defined in | | 1400 | | [MPLS-TP-OAM]. Each of the tools in the | | 1401 | | OAM toolset is defined in its own RFC, as| | 1402 | | specified in Section A.1. | | 1403 +-----------+------------------------------------------+------------+ 1404 |Pseudowire | The PWE3 OAM architecture defines control| Pseudowire | 1405 |OAM | channels that support the use of existing| | 1406 | | IETF OAM tools to be used for a pseudo- | | 1407 | | wire (PW). The control channels that are| | 1408 | | defined in [VCCV] and [PW-G-ACh] may be | | 1409 | | used in conjunction with ICMP Ping, LSP | | 1410 | | Ping, and BFD to perform CC and CV | | 1411 | | functionality. In addition the channels | | 1412 | | support use of any of the MPLS-TP based | | 1413 | | OAM tools for completing their respective| | 1414 | | OAM functionality for a PW. | | 1415 +-----------+------------------------------------------+------------+ 1416 |OWAMP and | The One Way Active Measurement Protocol | IPv4/IPv6 | 1417 |TWAMP | (OWAMP) and the Two Way Active Measure- | | 1418 | | ment Protocols (TWAMP) are two protocols | | 1419 | | defined in the IP Performance Metrics | | 1420 | | (IPPM) working group in the IETF. These | | 1421 | | protocols allow various performance | | 1422 | | metrics to be measured, such as packet | | 1423 | | loss, delay and delay variation, | | 1424 | | duplication and reordering. | | 1425 +-----------+------------------------------------------+------------+ 1426 |TRILL OAM | The requirements of OAM in TRILL are | TRILL | 1427 | | defined in [TRILL-OAM]. These | | 1428 | | requirements include continuity checking,| | 1429 | | connectivity verification, path tracing | | 1430 | | and performance monitoring. During the | | 1431 | | writing of this document the detailed | | 1432 | | definition of the TRILL OAM tools | | 1433 | | is work in progress. | | 1434 +-----------+------------------------------------------+------------+ 1435 Table 3 Summary of OAM-related IETF Tools 1437 4.10. Summary of OAM Functions 1439 Table 4 summarizes the OAM functions that are supported in each of 1440 the categories that were analyzed in this section. The columns of 1441 this tables are the typical OAM functions described in Section 1.3. 1443 +-----------+-------+--------+--------+-------+----------+ 1444 | |Continu|Connecti|Path |Perform|Other | 1445 | |ity |vity |Discover|ance |Function | 1446 | |Check |Verifica|y |Monitor|s | 1447 | Category | |tion | |ing | | 1448 +-----------+-------+--------+--------+-------+----------+ 1449 |IP Ping |Echo | | | | | 1450 + --------- + ----- + ------ + ------ + ----- + -------- + 1451 |IP | | |Tracerou| | | 1452 |Traceroute | | |te | | | 1453 + --------- + ----- + ------ + ------ + ----- + -------- + 1454 |BFD |BFD |BFD | | |RDI usi- | 1455 | |Control|Control | | |ng BFD | 1456 | |/ Echo | | | |Control | 1457 + --------- + ----- + ------ + ------ + ----- + -------- + 1458 |MPLS OAM | |"Ping" |"Tracero| | | 1459 |(LSP Ping) | |mode |ute" | | | 1460 | | | |mode | | | 1461 + --------- + ----- + ------ + ------ + ----- + -------- + 1462 |MPLS-TP |CC |CV/pro- |Route |-LM |-Diagnos- | 1463 |OAM | |active |Tracing |-DM | tic Test | 1464 | | |or on- | | |-Lock | 1465 | | |demand | | |-Alarm | 1466 | | | | | |Reporting | 1467 | | | | | |-Client | 1468 | | | | | |Failure | 1469 | | | | | |Indication| 1470 | | | | | |-RDI | 1471 + --------- + ----- + ------ + ------ + ----- + -------- + 1472 |Pseudowire |BFD |-BFD |LSP-Ping| | | 1473 |OAM | |-ICMP | | | | 1474 | | | Ping | | | | 1475 | | |-LSP- | | | | 1476 | | | Ping | | | | 1477 + --------- + ----- + ------ + ------ + ----- + -------- + 1478 |OWAMP and | - control | |-Delay | | 1479 |TWAMP | protocol | | measur| | 1480 | | | | ement | | 1481 | | | |-Packet| | 1482 | | | | loss | | 1483 | | | | measur| | 1484 | | | | ement | | 1485 + --------- + ----- + ------ + ------ + ----- + -------- + 1486 |TRILL OAM |CC |CV |Path |-Delay | | 1487 | | | |tracing | measur| | 1488 | | | | | ement | | 1489 | | | | |-Packet| | 1490 | | | | | loss | | 1491 | | | | | measur| | 1492 | | | | | ement | | 1493 +-----------+-------+--------+--------+-------+----------+ 1494 Table 4 Summary of the OAM Functionality in IETF OAM Tools 1496 5. Security Considerations 1498 This memo presents an overview of existing OAM tools, and proposes 1499 no new OAM tools. Therefore, this document introduces no security 1500 considerations. However, the OAM tools reviewed in this document can 1501 and do present security issues. The reader is encouraged to review 1502 the Security Considerations section of each document referenced by 1503 this memo. 1505 6. IANA Considerations 1507 There are no new IANA considerations implied by this document. 1509 7. Acknowledgments 1511 The authors gratefully acknowledge Sasha Vainshtein, Carlos 1512 Pignataro, David Harrington, Dan Romascanu, Ron Bonica and other 1513 members of the OPSAWG mailing list for their helpful comments. 1515 This document was prepared using 2-Word-v2.0.template.dot. 1517 8. References 1519 8.1. Informative References 1521 [ATM-L2] Singh, S., Townsley, M., and C. Pignataro, 1522 "Asynchronous Transfer Mode (ATM) over Layer 2 1523 Tunneling Protocol Version 3 (L2TPv3)", RFC 4454, May 1524 2006. 1526 [BFD] Katz, D., Ward, D., "Bidirectional Forwarding Detection 1527 (BFD)", RFC 5880, June 2010. 1529 [BFD-Gen] Katz, D., Ward, D., "Generic Application of 1530 Bidirectional Forwarding Detection (BFD)", RFC 5882, 1531 June 2010. 1533 [BFD-IP] Katz, D., Ward, D., "Bidirectional Forwarding Detection 1534 (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, June 1535 2010. 1537 [BFD-LSP] Aggarwal, R., Kompella, K., Nadeau, T., and Swallow, 1538 G., "Bidirectional Forwarding Detection (BFD) for MPLS 1539 Label Switched Paths (LSPs)", RFC 5884, June 2010. 1541 [BFD-Multi] Katz, D., Ward, D., "Bidirectional Forwarding Detection 1542 (BFD) for Multihop Paths", RFC 5883, June 2010. 1544 [BFD-VCCV] Nadeau, T., Pignataro, C., "Bidirectional Forwarding 1545 Detection (BFD) for the Pseudowire Virtual Circuit 1546 Connectivity Verification (VCCV)", RFC 5885, June 1547 2010. 1549 [Comp] Bonaventure, O., "Computer Networking: Principles, 1550 Protocols and Practice", 2008. 1552 [Cont] Dugal, D., Pignataro, C., Dunn, R., "Protecting the 1553 Router Control Plane", RFC 6192, March 2011. 1555 [Dup] Uijterwaal, H., "A One-Way Packet Duplication Metric", 1556 RFC 5560, May 2009. 1558 [G-ACh] Bocci, M., Vigoureux, M., Bryant, S., "MPLS Generic 1559 Associated Channel", RFC 5586, June 2009. 1561 [ICMP-Ext] Bonica, R., Gan, D., Tappan, D., Pignataro, C., "ICMP 1562 Extensions for Multiprotocol Label Switching", RFC 1563 4950, August 2007. 1565 [ICMP-Int] Atlas, A., Bonica, R., Pignataro, C., Shen, N., Rivers, 1566 JR., "Extending ICMP for Interface and Next-Hop 1567 Identification", RFC 5837, April 2010. 1569 [ICMP-MP] Bonica, R., Gan, D., Tappan, D., Pignataro, C., 1570 "Extended ICMP to Support Multi-Part Messages", RFC 1571 4884, April 2007. 1573 [ICMPv4] Postel, J., "Internet Control Message Protocol", STD 5, 1574 RFC 792, September 1981. 1576 [ICMPv6] Conta, A., Deering, S., and M. Gupta, "Internet Control 1577 Message Protocol (ICMPv6) for the Internet Protocol 1578 Version 6 (IPv6) Specification", RFC 4443, March 2006. 1580 [IEEE802.1Q] IEEE 802.1Q, "IEEE Standard for Local and metropolitan 1581 area networks - Media Access Control (MAC) Bridges and 1582 Virtual Bridged Local Area Networks", October 2012. 1584 [IEEE802.3ah] IEEE 802.3, "IEEE Standard for Information technology - 1585 Local and metropolitan area networks - Carrier sense 1586 multiple access with collision detection (CSMA/CD) 1587 access method and physical layer specifications", 1588 clause 57, December 2008. 1590 [IntHost] Braden, R., "Requirements for Internet Hosts -- 1591 Communication Layers", RFC 1122, October 1989. 1593 [IPPM-1DM] Almes, G., Kalidindi, S., Zekauskas, M., "A One-way 1594 Delay Metric for IPPM", RFC 2679, September 1999. 1596 [IPPM-1LM] Almes, G., Kalidindi, S., Zekauskas, M., "A One-way 1597 Packet Loss Metric for IPPM", RFC 2680, September 1598 1999. 1600 [IPPM-2DM] Almes, G., Kalidindi, S., Zekauskas, M., "A Round-trip 1601 Delay Metric for IPPM", RFC 2681, September 1999. 1603 [IPPM-Con] Mahdavi, J., Paxson, V., "IPPM Metrics for Measuring 1604 Connectivity", RFC 2678, September 1999. 1606 [IPPM-FW] Paxson, V., Almes, G., Mahdavi, J., and Mathis, M., 1607 "Framework for IP Performance Metrics", RFC 2330, May 1608 1998. 1610 [ITU-G8113.1] ITU-T Recommendation G.8113.1/Y.1372.1, "Operations, 1611 Administration and Maintenance mechanism for MPLS-TP 1612 in Packet Transport Network (PTN)", November 2012. 1614 [ITU-G8113.2] ITU-T Recommendation G.8113.2/Y.1372.2, "Operations, 1615 administration and maintenance mechanisms for MPLS-TP 1616 networks using the tools defined for MPLS", November 1617 2012. 1619 [ITU-T-CT] Betts, M., "Allocation of a Generic Associated Channel 1620 Type for ITU-T MPLS Transport Profile Operation, 1621 Maintenance, and Administration (MPLS-TP OAM)", RFC 1622 6671, November 2012. 1624 [ITU-T-G.806] ITU-T Recommendation G.806, "Characteristics of 1625 transport equipment - Description methodology and 1626 generic functionality", January 2009. 1628 [ITU-T-Y1711] ITU-T Recommendation Y.1711, "Operation & Maintenance 1629 mechanism for MPLS networks", February 2004. 1631 [ITU-T-Y1731] ITU-T Recommendation G.8013/Y.1731, "OAM Functions and 1632 Mechanisms for Ethernet-based Networks", July 2011. 1634 [ITU-Terms] ITU-R/ITU-T Terms and Definitions, online, 2013. 1636 [L2TP-EC] McGill, N. and C. Pignataro, "Layer 2 Tunneling 1637 Protocol Version 3 (L2TPv3) Extended Circuit Status 1638 Values", RFC 5641, August 2009. 1640 [Lock-Loop] Boutros, S., Sivabalan, S., Aggarwal, R., Vigoureux, 1641 M., Dai, X., "MPLS Transport Profile Lock Instruct and 1642 Loopback Functions", RFC 6435, November 2011. 1644 [LSP-Ping] Kompella, K., Swallow, G., "Detecting Multi-Protocol 1645 Label Switched (MPLS) Data Plane Failures", RFC 4379, 1646 February 2006. 1648 [Mng] Farrel, A., "Inclusion of Manageability Sections in 1649 Path Computation Element (PCE) Working Group Drafts", 1650 RFC 6123, February 2011. 1652 [MPLS-LM-DM] Frost, D., Bryant, S., "Packet Loss and Delay 1653 Measurement for MPLS Networks", RFC 6374, September 1654 2011. 1656 [MPLS-OAM] Nadeau, T., Morrow, M., Swallow, G., Allan, D., 1657 Matsushima, S., "Operations and Management (OAM) 1658 Requirements for Multi-Protocol Label Switched (MPLS) 1659 Networks", RFC 4377, February 2006. 1661 [MPLS-OAM-FW] Allan, D., Nadeau, T., "A Framework for Multi-Protocol 1662 Label Switching (MPLS) Operations and Management 1663 (OAM)", RFC 4378, February 2006. 1665 [MPLS-P2MP] Yasukawa, S., Farrel, A., King, D., Nadeau, T., 1666 "Operations and Management (OAM) Requirements for 1667 Point-to-Multipoint MPLS Networks", RFC 4687, 1668 September 2006. 1670 [MPLS-TP-OAM] Vigoureux, M., Ward, D., Betts, M., "Requirements for 1671 OAM in MPLS Transport Networks", RFC 5860, May 2010. 1673 [NetTerms] Jacobsen, O., Lynch, D., "A Glossary of Networking 1674 Terms", RFC 1208, March 1991. 1676 [NetTools] Enger, R., Reynolds, J., "FYI on a Network Management 1677 Tool Catalog: Tools for Monitoring and Debugging 1678 TCP/IP Internets and Interconnected Devices", RFC 1679 1470, June 1993. 1681 [OAM-Analys] Sprecher, N., Fang, L., "An Overview of the OAM Tool 1682 Set for MPLS based Transport Networks", RFC 6669, 1683 July 2012. 1685 [OAM-Def] Andersson, L., Van Helvoort, H., Bonica, R., Romascanu, 1686 D., Mansfield, S., "Guidelines for the use of the OAM 1687 acronym in the IETF ", RFC 6291, June 2011. 1689 [OAM-Label] Ohta, H., "Assignment of the 'OAM Alert Label' for 1690 Multiprotocol Label Switching Architecture (MPLS) 1691 Operation and Maintenance (OAM) Functions", RFC 3429, 1692 November 2002. 1694 [OnDemand-CV] Gray, E., Bahadur, N., Boutros, S., Aggarwal, R. "MPLS 1695 On-Demand Connectivity Verification and Route 1696 Tracing", RFC 6426, November 2011. 1698 [OWAMP] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and 1699 Zekauskas, M., "A One-way Active Measurement Protocol 1700 (OWAMP)", RFC 4656, September 2006. 1702 [PARIS] Brice Augustin, Timur Friedman and Renata Teixeira, 1703 "Measuring Load-balanced Paths in the Internet", IMC, 1704 2007. 1706 [PM-CONS] Clark, A. and B. Claise, "Guidelines for Considering 1707 New Performance Metric Development", BCP 170, RFC 1708 6390, October 2011. 1710 [PW-ACH] Bryant, S., Swallow, G., Martini, L., McPherson, D., 1711 "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word 1712 for Use over an MPLS PSN", RFC 4385, February 2006. 1714 [PW-G-ACh] Li, H., Martini, L., He, J., Huang, F., "Using the 1715 Generic Associated Channel Label for Pseudowire in the 1716 MPLS Transport Profile (MPLS-TP)", RFC 6423, November 1717 2011. 1719 [PW-MAP] Aissaoui, M., Busschbach, P., Martini, L., Morrow, M., 1720 Nadeau, T., and Y(J). Stein, "Pseudowire (PW) 1721 Operations, Administration, and Maintenance (OAM) 1722 Message Mapping", RFC 6310, July 2011. 1724 [PW-Map] M. Aissaoui, P. Busschbach, L. Martini, M. Morrow, T. 1725 Nadeau, "Pseudowire (PW) Operations, Administration, 1726 and Maintenance (OAM) Message Mapping", RFC 6310, July 1727 2011. 1729 [Reorder] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov, 1730 S., and J. Perser, "Packet Reordering Metrics", RFC 1731 4737, November 2006. 1733 [Signal] Yasukawa, S., "Signaling Requirements for Point-to- 1734 Multipoint Traffic-Engineered MPLS Label Switched 1735 Paths (LSPs)", RFC 4461, April 2006. 1737 [TCPIP-Tools] Kessler, G., Shepard, S., "A Primer On Internet and 1738 TCP/IP Tools and Utilities", RFC 2151, June 1997. 1740 [TP-CC-CV] Allan, D., Swallow, G., Drake, J., "Proactive 1741 Connectivity Verification, Continuity Check and Remote 1742 Defect indication for MPLS Transport Profile", RFC 1743 6428, November 2011. 1745 [TP-Fault] Swallow, G., Fulignoli, A., Vigoureux, M., Boutros, S., 1746 "MPLS Fault Management Operations, Administration, and 1747 Maintenance (OAM)", RFC 6427, November 2011. 1749 [TP-LM-DM] Frost, D., Bryant, S., "A Packet Loss and Delay 1750 Measurement Profile for MPLS-Based Transport 1751 Networks", RFC 6375, September 2011. 1753 [TP-OAM-FW] Busi, I., Allan, D., "Operations, Administration and 1754 Maintenance Framework for MPLS-based Transport 1755 Networks ", RFC 6371, September 2011. 1757 [TP-Term] Van Helvoort, H., Andersson, L., Sprecher, N., "A 1758 Thesaurus for the Terminology used in Multiprotocol 1759 Label Switching Transport Profile (MPLS-TP) 1760 drafts/RFCs and ITU-T's Transport Network 1761 Recommendations", work-in-progress, draft-ietf-mpls- 1762 tp-rosetta-stone, July 2012. 1764 [TRILL-OAM] Senevirathne, T., Bond, D., Aldrin, S., Li, Y., Watve, 1765 R., "Requirements for Operations, Administration, and 1766 Maintenance (OAM) in Transparent Interconnection of 1767 Lots of Links (TRILL)", RFC 6905, March 2013. 1769 [TWAMP] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and 1770 Babiarz, J., "A Two-Way Active Measurement Protocol 1771 (TWAMP)", RFC 5357, October 2008. 1773 [VCCV] Nadeau, T., Pignataro, C., "Pseudowire Virtual Circuit 1774 Connectivity Verification (VCCV): A Control Channel 1775 for Pseudowires", RFC 5085, December 2007. 1777 [VCCV-SURVEY] Del Regno, N., Malis, A., "The Pseudowire (PW) & 1778 Virtual Circuit Connectivity Verification (VCCV) 1779 Implementation Survey Results", work-in-progress, 1780 draft-ietf-pwe3-vccv-impl-survey-results, August 2013. 1782 Appendix A. List of OAM Documents 1784 A.1. List of IETF OAM Documents 1786 Table 5 summarizes the OAM related RFCs published by the IETF. 1788 It is important to note that the table lists various RFCs that are 1789 different by nature. For example, some of these documents define OAM 1790 tools or OAM protocols (or both), while others define protocols that 1791 are not strictly OAM-related, but are used by OAM tools. The table 1792 also includes RFCs that define the requirements or the framework of 1793 OAM in a specific context (e.g., MPLS-TP). 1795 The RFCs in the table are categorized in a few sets as defined in 1796 Section 1.3. 1798 +-----------+--------------------------------------+----------+ 1799 | Category | Title | RFC | 1800 +-----------+--------------------------------------+----------+ 1801 |IP Ping | Requirements for Internet Hosts -- | RFC 1122 | 1802 | | Communication Layers [IntHost] | | 1803 | +--------------------------------------+----------+ 1804 | | A Glossary of Networking Terms | RFC 1208 | 1805 | | [NetTerms] | | 1806 | +--------------------------------------+----------+ 1807 | | Internet Control Message Protocol | RFC 792 | 1808 | | [ICMPv4] | | 1809 | +--------------------------------------+----------+ 1810 | | Internet Control Message Protocol | RFC 4443 | 1811 | | (ICMPv6) for the Internet Protocol | | 1812 | | Version 6 (IPv6) Specification | | 1813 | | [ICMPv6] | | 1814 +-----------+--------------------------------------+----------+ 1815 |IP | A Primer On Internet and TCP/IP | RFC 2151 | 1816 |Traceroute | Tools and Utilities [TCPIP-Tools] | | 1817 | +--------------------------------------+----------+ 1818 | | FYI on a Network Management Tool | RFC 1470 | 1819 | | Catalog: Tools for Monitoring and | | 1820 | | Debugging TCP/IP Internets and | | 1821 | | Interconnected Devices [NetTools] | | 1822 | +--------------------------------------+----------+ 1823 | | Internet Control Message Protocol | RFC 792 | 1824 | | [ICMPv4] | | 1825 | +--------------------------------------+----------+ 1826 | | Internet Control Message Protocol | RFC 4443 | 1827 | | (ICMPv6) for the Internet Protocol | | 1828 | | Version 6 (IPv6) Specification | | 1829 | | [ICMPv6] | | 1830 | +--------------------------------------+----------+ 1831 | | Extended ICMP to Support Multi-Part | RFC 4884 | 1832 | | Messages [ICMP-MP] | | 1833 | +--------------------------------------+----------+ 1834 | | Extending ICMP for Interface and | RFC 5837 | 1835 | | Next-Hop Identification [ICMP-Int] | | 1836 +-----------+--------------------------------------+----------+ 1837 |BFD | Bidirectional Forwarding Detection | RFC 5880 | 1838 | | [BFD] | | 1839 | +--------------------------------------+----------+ 1840 | | Bidirectional Forwarding Detection | RFC 5881 | 1841 | | (BFD) for IPv4 and IPv6 (Single Hop) | | 1842 | | [BFD-IP] | | 1843 | +--------------------------------------+----------+ 1844 | | Generic Application of Bidirectional | RFC 5882 | 1845 | | Forwarding Detection [BFD-Gen] | | 1846 | +--------------------------------------+----------+ 1847 | | Bidirectional Forwarding Detection | RFC 5883 | 1848 | | (BFD) for Multihop Paths [BFD-Multi] | | 1849 | +--------------------------------------+----------+ 1850 | | Bidirectional Forwarding Detection | RFC 5884 | 1851 | | for MPLS Label Switched Paths (LSPs) | | 1852 | | [BFD-LSP] | | 1853 | +--------------------------------------+----------+ 1854 | | Bidirectional Forwarding Detection | RFC 5885 | 1855 | | for the Pseudowire Virtual Circuit | | 1856 | | Connectivity Verification (VCCV) | | 1857 | | [BFD-VCCV] | | 1858 +-----------+--------------------------------------+----------+ 1859 |MPLS OAM | Operations and Management (OAM) | RFC 4377 | 1860 | | Requirements for Multi-Protocol Label| | 1861 | | Switched (MPLS) Networks [MPLS-OAM] | | 1862 | +--------------------------------------+----------+ 1863 | | A Framework for Multi-Protocol | RFC 4378 | 1864 | | Label Switching (MPLS) Operations | | 1865 | | and Management (OAM) [MPLS-OAM-FW] | | 1866 | +--------------------------------------+----------+ 1867 | | Detecting Multi-Protocol Label | RFC 4379 | 1868 | | Switched (MPLS) Data Plane Failures | | 1869 | | [LSP-Ping] | | 1870 | +--------------------------------------+----------+ 1871 | | Operations and Management (OAM) | RFC 4687 | 1872 | | Requirements for Point-to-Multipoint | | 1873 | | MPLS Networks [MPLS-P2MP] | | 1874 | +--------------------------------------+----------+ 1875 | | ICMP Extensions for Multiprotocol | RFC 4950 | 1876 | | Label Switching [ICMP-Ext] | | 1877 +-----------+--------------------------------------+----------+ 1878 |MPLS-TP | Requirements for OAM in MPLS-TP | RFC 5860 | 1879 |OAM | [MPLS-TP-OAM] | | 1880 | +--------------------------------------+----------+ 1881 | | MPLS Generic Associated Channel | RFC 5586 | 1882 | | [G-ACh] | | 1883 | +--------------------------------------+----------+ 1884 | | MPLS-TP OAM Framework | RFC 6371 | 1885 | | [TP-OAM-FW] | | 1886 | +--------------------------------------+----------+ 1887 | | Proactive Connectivity Verification, | RFC 6428 | 1888 | | Continuity Check, and Remote Defect | | 1889 | | Indication for the MPLS Transport | | 1890 | | Profile [TP-CC-CV] | | 1891 | +--------------------------------------+----------+ 1892 | | MPLS On-Demand Connectivity | RFC 6426 | 1893 | | Verification and Route Tracing | | 1894 | | [OnDemand-CV] | | 1895 | +--------------------------------------+----------+ 1896 | | MPLS Fault Management Operations, | RFC 6427 | 1897 | | Administration, and Maintenance (OAM)| | 1898 | | [TP-Fault] | | 1899 | +--------------------------------------+----------+ 1900 | | MPLS Transport Profile Lock Instruct | RFC 6435 | 1901 | | and Loopback Functions [Lock-Loop] | | 1902 | +--------------------------------------+----------+ 1903 | | Packet Loss and Delay Measurement for| RFC 6374 | 1904 | | MPLS Networks [MPLS-LM-DM] | | 1905 | +--------------------------------------+----------+ 1906 | | A Packet Loss and Delay Measurement | RFC 6375 | 1907 | | Profile for MPLS-Based Transport | | 1908 | | Networks [TP-LM-DM] | | 1909 +-----------+--------------------------------------+----------+ 1910 |Pseudowire | Pseudowire Virtual Circuit | RFC 5085 | 1911 |OAM | Connectivity Verification (VCCV): | | 1912 | | A Control Channel for Pseudowires | | 1913 | | [VCCV] | | 1914 | +--------------------------------------+----------+ 1915 | | Bidirectional Forwarding Detection | RFC 5885 | 1916 | | for the Pseudowire Virtual Circuit | | 1917 | | Connectivity Verification (VCCV) | | 1918 | | [BFD-VCCV] | | 1919 | +--------------------------------------+----------+ 1920 | | Using the Generic Associated Channel | RFC 6423 | 1921 | | Label for Pseudowire in the MPLS | | 1922 | | Transport Profile (MPLS-TP) | | 1923 | | [PW-G-ACh] | | 1924 | +--------------------------------------+----------+ 1925 | | Pseudowire (PW) Operations, | RFC 6310 | 1926 | | Administration, and Maintenance (OAM)| | 1927 | | Message Mapping [PW-Map] | | 1928 +-----------+--------------------------------------+----------+ 1929 |OWAMP and | A One-way Active Measurement Protocol| RFC 4656 | 1930 |TWAMP | [OWAMP] | | 1931 | +--------------------------------------+----------+ 1932 | | A Two-Way Active Measurement Protocol| RFC 5357 | 1933 | | [TWAMP] | | 1934 | +--------------------------------------+----------+ 1935 | | Framework for IP Performance Metrics | RFC 2330 | 1936 | | [IPPM-FW] | | 1937 | +--------------------------------------+----------+ 1938 | | IPPM Metrics for Measuring | RFC 2678 | 1939 | | Connectivity [IPPM-Con] | | 1940 | +--------------------------------------+----------+ 1941 | | A One-way Delay Metric for IPPM | RFC 2679 | 1942 | | [IPPM-1DM] | | 1943 | +--------------------------------------+----------+ 1944 | | A One-way Packet Loss Metric for IPPM| RFC 2680 | 1945 | | [IPPM-1LM] | | 1946 | +--------------------------------------+----------+ 1947 | | A Round-trip Delay Metric for IPPM | RFC 2681 | 1948 | | [IPPM-2DM] | | 1949 | +--------------------------------------+----------+ 1950 | | Packet Reordering Metrics | RFC 4737 | 1951 | | [Reorder] | | 1952 | +--------------------------------------+----------+ 1953 | | A One-Way Packet Duplication Metric | RFC 5560 | 1954 | | [Dup] | | 1955 +-----------+--------------------------------------+----------+ 1956 |TRILL OAM | Requirements for Operations, | RFC 6905 | 1957 | | Administration, and Maintenance (OAM)| | 1958 | | in Transparent Interconnection of | | 1959 | | Lots of Links (TRILL) | | 1960 +-----------+--------------------------------------+----------+ 1961 Table 5 Summary of IETF OAM Related RFCs 1963 A.2. List of Selected Non-IETF OAM Documents 1965 In addition to the OAM tools defined by the IETF, the IEEE and ITU-T 1966 have also defined various OAM tools that focus on Ethernet, and 1967 various other transport network environments. These various tools, 1968 defined by the three standard organizations, are often tightly 1969 coupled, and have had a mutual effect on each other. The ITU-T and 1970 IETF have both defined OAM tools for MPLS LSPs, [ITU-T-Y1711] and 1971 [LSP-Ping]. The following OAM standards by the IEEE and ITU-T are to 1972 some extent linked to IETF OAM tools listed above and are mentioned 1973 here only as reference material: 1975 o OAM tools for Layer 2 have been defined by the ITU-T in 1976 [ITU-T-Y1731], and by the IEEE in 802.1ag [IEEE802.1Q] . The IEEE 1977 802.3 standard defines OAM for one-hop Ethernet links 1978 [IEEE802.3ah]. 1980 o The ITU-T has defined OAM for MPLS LSPs in [ITU-T-Y1711], and 1981 MPLS-TP OAM in [ITU-G8113.1] and [ITU-G8113.2]. 1983 It should be noted that these non-IETF documents deal in many cases 1984 with OAM functions below the IP layer (Layer 2, Layer 2.5) and in 1985 some cases operators use a multi-layered OAM approach, which is a 1986 function of the way their networks are designed. 1988 Table 6 summarizes some of the main OAM standards published by non- 1989 IETF standard organizations. This document focuses on IETF OAM 1990 standards, but these non-IETF standards are referenced in this 1991 document where relevant. 1993 +-----------+--------------------------------------+---------------+ 1994 | | Title |Standard/Draft | 1995 +-----------+--------------------------------------+---------------+ 1996 |ITU-T | Operation & Maintenance mechanism | ITU-T Y.1711 | 1997 |MPLS OAM | for MPLS networks [ITU-T-Y1711] | | 1998 | +--------------------------------------+---------------+ 1999 | | Assignment of the 'OAM Alert Label' | RFC 3429 | 2000 | | for Multiprotocol Label Switching | | 2001 | | Architecture (MPLS) Operation and | | 2002 | | Maintenance (OAM) Functions | | 2003 | | [OAM-Label] | | 2004 | | | | 2005 | | Note: although this is an IETF | | 2006 | | document, it is listed as one of the| | 2007 | | non-IETF OAM standards, since it | | 2008 | | was defined as a complementary part | | 2009 | | of ITU-T Y.1711. | | 2010 +-----------+--------------------------------------+---------------+ 2011 |ITU-T | Operations, administration and |ITU-T G.8113.2 | 2012 |MPLS-TP OAM| Maintenance mechanisms for MPLS-TP | | 2013 | | networks using the tools defined for | | 2014 | | MPLS [ITU-G8113.2] | | 2015 | | | | 2016 | | Note: this document describes the | | 2017 | | OAM toolset defined by the IETF for | | 2018 | | MPLS-TP, whereas ITU-T G.8113.1 | | 2019 | | describes the OAM toolset defined | | 2020 | | by the ITU-T. | | 2021 | +--------------------------------------+---------------+ 2022 | | Operations, Administration and |ITU-T G.8113.1 | 2023 | | Maintenance mechanism for MPLS-TP in | | 2024 | | Packet Transport Network (PTN) | | 2025 | +--------------------------------------+---------------+ 2026 | | Allocation of a Generic Associated | RFC 6671 | 2027 | | Channel Type for ITU-T MPLS Transport| | 2028 | | Profile Operation, Maintenance, and | | 2029 | | Administration (MPLS-TP OAM) | | 2030 | | [ITU-T-CT] | | 2031 | | | | 2032 | | Note: although this is an IETF | | 2033 | | document, it is listed as one of the| | 2034 | | non-IETF OAM standards, since it | | 2035 | | was defined as a complementary part | | 2036 | | of ITU-T G.8113.1. | | 2037 +-----------+--------------------------------------+---------------+ 2038 |ITU-T | OAM Functions and Mechanisms for | ITU-T Y.1731 | 2039 |Ethernet | Ethernet-based Networks | | 2040 |OAM | [ITU-T-Y1731] | | 2041 +-----------+--------------------------------------+---------------+ 2042 |IEEE | Connectivity Fault Management | IEEE 802.1ag | 2043 |CFM | [IEEE802.1Q] | | 2044 | | | | 2045 | | Note: CFM was originally published | | 2046 | | as IEEE 802.1ag, but is now | | 2047 | | incorporated in the 802.1Q standard.| | 2048 +-----------+--------------------------------------+---------------+ 2049 |IEEE | Management of Data Driven and Data | IEEE 802.1ag | 2050 |DDCFM | Dependent Connectivity Faults | | 2051 | | [IEEE802.1Q] | | 2052 | | | | 2053 | | Note: DDCFM was originally published| | 2054 | | as IEEE 802.1Qaw, but is now | | 2055 | | incorporated in the 802.1Q standard.| | 2056 +-----------+--------------------------------------+---------------+ 2057 |IEEE | Media Access Control Parameters, | IEEE 802.3ah | 2058 |802.3 | Physical Layers, and Management | | 2059 |link level | Parameters for Subscriber Access | | 2060 |OAM | Networks [IEEE802.3ah] | | 2061 | | | | 2062 | | Note: link level OAM was originally | | 2063 | | defined in IEEE 802.3ah, and is now | | 2064 | | incorporated in the 802.3 standard. | | 2065 +-----------+--------------------------------------+---------------+ 2066 Table 6 Non-IETF OAM Standards Mentioned in this Document 2068 Authors' Addresses 2070 Tal Mizrahi 2071 Marvell 2072 6 Hamada St. 2073 Yokneam, 20692 2074 Israel 2076 Email: talmi@marvell.com 2078 Nurit Sprecher 2079 Nokia Siemens Networks 2080 3 Hanagar St. Neve Ne'eman B 2081 Hod Hasharon, 45241 2082 Israel 2084 Email: nurit.sprecher@nsn.com 2086 Elisa Bellagamba 2087 Ericsson 2088 6 Farogatan St. 2089 Stockholm, 164 40 2090 Sweden 2092 Phone: +46 761440785 2093 Email: elisa.bellagamba@ericsson.com 2095 Yaacov Weingarten 2096 34 Hagefen St. 2097 Karnei Shomron, 4485500 2098 Israel 2100 Email: wyaacov@gmail.com