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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Missing reference section? 'PWE3-CTRL' on line 1109 looks like a reference -- Missing reference section? 'PWE3-ETHERNET' on line 1105 looks like a reference -- Missing reference section? 'L2VPN-REQ' on line 1153 looks like a reference -- Missing reference section? 'MPLS-GRE' on line 192 looks like a reference -- Missing reference section? 'BGP-VPN' on line 1126 looks like a reference -- Missing reference section? 'BGP-DISC' on line 1136 looks like a reference -- Missing reference section? 'RADIUS-DISC' on line 1132 looks like a reference -- Missing reference section? 'LDP-DISC' on line 1140 looks like a reference -- Missing reference section? 'VPLS-BRIDGING' on line 1144 looks like a reference -- Missing reference section? 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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet Draft Document Marc Lasserre 3 Provider Provisioned VPN Working Group Riverstone Networks 4 draft-ietf-l2vpn-vpls-ldp-00.txt Vach Kompella 5 Nick Tingle 6 Sunil Khandekar 7 Timetra Networks 9 Ali Sajassi 10 Cisco Systems 12 Pascal Menezes Loa Andersson 13 Terabeam Networks Consultant 15 Andrew Smith Pierre Lin 16 Consultant Yipes Communication 18 Juha Heinanen Giles Heron 19 Song Networks PacketExchange Ltd. 21 Ron Haberman Tom S.C. Soon 22 Masergy, Inc. Yetik Serbest 23 Eric Puetz 24 Nick Slabakov SBC Communications 25 Rob Nath 26 Riverstone Networks 27 Luca Martini 28 Vasile Radaoca Level 3 29 Nortel Networks Communications 31 Expires: December 2003 June 2003 33 Virtual Private LAN Services over MPLS 34 draft-ietf-l2vpn-vpls-ldp-00.txt 36 1. Status of this Memo 38 This document is an Internet-Draft and is in full conformance 39 with all provisions of Section 10 of RFC2026. 41 Internet-Drafts are working documents of the Internet Engineering 42 Task Force (IETF), its areas, and its working groups. Note that 43 other groups may also distribute working documents as Internet- 44 Drafts. 46 Internet-Drafts are draft documents valid for a maximum of six 47 months and may be updated, replaced, or obsoleted by other documents 48 at any time. It is inappropriate to use Internet-Drafts as 49 reference material or to cite them other than as "work in progress." 51 The list of current Internet-Drafts can be accessed at 52 http://www.ietf.org/ietf/1id-abstracts.txt 54 The list of Internet-Draft Shadow Directories can be accessed at 55 http://www.ietf.org/shadow.html. 57 2. Abstract 59 This document describes a virtual private LAN service (VPLS) 60 solution over MPLS, also known as Transparent LAN Services (TLS). A 61 VPLS creates an emulated LAN segment for a given set of users. It 62 delivers a layer 2 broadcast domain that is fully capable of 63 learning and forwarding on Ethernet MAC addresses that is closed to 64 a given set of users. Many VPLS services can be supported from a 65 single PE node. 67 This document describes the control plane functions of signaling 68 demultiplexor labels, extending [PWE3-CTRL] and rudimentary support 69 for availability (multi-homing). It is agnostic to discovery 70 protocols. The data plane functions of forwarding are also 71 described, focusing, in particular, on the learning of MAC 72 addresses. The encapsulation of VPLS packets is described by [PWE3- 73 ETHERNET]. 75 3. Conventions 77 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 78 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 79 document are to be interpreted as described in RFC 2119 81 Placement of this Memo in Sub-IP Area 83 RELATED DOCUMENTS 85 www.ietf.org/internet-drafts/draft-ietf-ppvpn-l2vpn-requirements- 86 01.txt 87 www.ietf.org/internet-drafts/draft-ietf-ppvpn-l2-framework-03.txt 88 www.ietf.org/internet-drafts/draft-ietf-pwe3-ethernet-encap-02.txt 89 www.ietf.org/internet-drafts/draft-ietf-pwe3-control-protocol-01.txt 91 WHERE DOES THIS FIT IN THE PICTURE OF THE SUB-IP WORK 93 PPVPN 95 WHY IS IT TARGETED AT THIS WG 97 The charter of the PPVPN WG includes L2 VPN services and this draft 98 specifies a model for Ethernet L2 VPN services over MPLS. 100 JUSTIFICATION 102 Existing Internet drafts specify how to provide point-to-point 103 Ethernet L2 VPN services over MPLS. This draft defines how 104 multipoint Ethernet services can be provided. 106 Table of Contents 108 1. Status of this Memo.............................................1 109 2. Abstract........................................................2 110 3. Conventions.....................................................2 111 4. Overview........................................................4 112 5. Topological Model for VPLS......................................5 113 5.1. Flooding and Forwarding.......................................5 114 5.2. Address Learning..............................................6 115 5.3. LSP Topology..................................................6 116 5.4. Loop free L2 VPN..............................................7 117 6. Discovery.......................................................7 118 7. Control Plane...................................................7 119 7.1. LDP Based Signaling of Demultiplexors.........................7 120 7.2. MAC Address Withdrawal........................................9 121 7.2.1. MAC TLV.....................................................9 122 7.2.2. Address Withdraw Message Containing MAC TLV................10 123 8. Data Forwarding on an Ethernet VC Type.........................11 124 8.1. VPLS Encapsulation actions...................................11 125 8.1.1. VPLS Learning actions......................................12 126 9. Operation of a VPLS............................................12 127 9.1. MAC Address Aging............................................13 128 10. A Hierarchical VPLS Model.....................................13 129 10.1. Hierarchical connectivity...................................14 130 10.1.1. Spoke connectivity for bridging-capable devices...........14 131 10.1.2. Advantages of spoke connectivity..........................16 132 10.1.3. Spoke connectivity for non-bridging devices...............17 133 10.2. Redundant Spoke Connections.................................18 134 10.2.1. Dual-homed MTU device.....................................18 135 10.2.2. Failure detection and recovery............................19 136 10.3. Multi-domain VPLS service...................................20 137 11. Hierarchical VPLS model using Ethernet Access Network.........20 138 11.1. Scalability.................................................21 139 11.2. Dual Homing and Failure Recovery............................21 140 12. Significant Modifications.....................................22 141 13. Acknowledgments...............................................22 142 14. Security Considerations.......................................22 143 15. Intellectual Property Considerations..........................22 144 16. Full Copyright Statement......................................22 145 17. References....................................................23 146 18. Authors' Addresses............................................24 147 4. Overview 149 Ethernet has become the predominant technology for Local Area 150 Networks (LANs) connectivity and is gaining acceptance as an access 151 technology, specifically in Metropolitan and Wide Area Networks (MAN 152 and WAN respectively). An Ethernet port is used to connect a 153 customer to the Provider Edge (PE) router acting as an LER. Customer 154 traffic is subsequently mapped to a specific MPLS L2 VPN by 155 configuring L2 FECs based upon the input port ID and/or VLAN tag 156 depending upon the VPLS service. 158 Broadcast and multicast services are available over traditional 159 LANs. MPLS does not support such services currently. Sites that 160 belong to the same broadcast domain and that are connected via an 161 MPLS network expect broadcast, multicast and unicast traffic to be 162 forwarded to the proper location(s). This requires MAC address 163 learning/aging on a per LSP basis, packet replication across LSPs 164 for multicast/broadcast traffic and for flooding of unknown unicast 165 destination traffic. 167 The primary motivation behind Virtual Private LAN Services (VPLS) is 168 to provide connectivity between geographically dispersed customer 169 sites across MAN/WAN network(s), as if they were connected using a 170 LAN. The intended application for the end-user can be divided into 171 the following two categories: 173 - Connectivity between customer routers � LAN routing application 174 - Connectivity between customer Ethernet switches � LAN switching 175 application 177 [PWE3-ETHERNET] defines how to carry L2 PDUs over point-to-point 178 MPLS LSPs, called pseudowires (PW). Such PWs can be carried over 179 MPLS or GRE tunnels. This document describes extensions to [PWE3- 180 CTRL] for transporting Ethernet/802.3 and VLAN [802.1Q] traffic 181 across multiple sites that belong to the same L2 broadcast domain or 182 VPLS. Note that the same model can be applied to other 802.1 183 technologies. It describes a simple and scalable way to offer 184 Virtual LAN services, including the appropriate flooding of 185 Broadcast, Multicast and unknown unicast destination traffic over 186 MPLS, without the need for address resolution servers or other 187 external servers, as discussed in [L2VPN-REQ]. 189 The following discussion applies to devices that are VPLS capable 190 and have a means of tunneling labeled packets amongst each other. 191 While MPLS LSPs may be used to tunnel these labeled packets, other 192 technologies may be used as well, e.g., GRE [MPLS-GRE]. The 193 resulting set of interconnected devices forms a private MPLS VPN. 195 5. Topological Model for VPLS 197 An interface participating in a VPLS must be able to flood, forward, 198 and filter ethernet frames. 200 +----+ +----+ 201 + C1 +---+ ........................... +---| C1 | 202 +----+ | . . | +----+ 203 Site A | +----+ +----+ | Site B 204 +---| PE |------ Cloud -------| PE |---+ 205 +----+ | +----+ 206 . | . 207 . +----+ . 208 ..........| PE |........... 209 +----+ ^ 210 | | 211 | +-- Emulated LAN 212 +----+ 213 | C1 | 214 +----+ 215 Site C 217 The set of PE devices interconnected via pseudowires appears as a 218 single emulated LAN to customer C1. Each PE device will learn remote 219 MAC address to pseudowire associations and will also learn directly 220 attached MAC addresses on customer facing ports. 222 We note here again that while this document shows specific examples 223 using MPLS transport tunnels, other tunnels that can be used by 224 pseudo-wires, e.g., GRE, L2TP, IPSEC, etc., can also be used, as 225 long as the originating PE can be identified, since this is used in 226 the MAC learning process. 228 The scope of the VPLS lies within the PEs in the service provider 229 network, highlighting the fact that apart from customer service 230 delineation, the form of access to a customer site is not relevant 231 to the VPLS [L2VPN-REQ]. 233 The PE device is typically an edge router capable of running a 234 signaling protocol and/or routing protocols to set up pseudowires. 235 In addition, it is capable of setting up transport tunnels to other 236 PEs and deliver traffic over a pseudowire. 238 5.1. Flooding and Forwarding 240 One of attributes of an Ethernet service is that all broadcast and 241 destination unknown MAC addresses are flooded to all ports. To 242 achieve flooding within the service provider network, all address 243 unknown unicast, broadcast and multicast frames are flooded over the 244 corresponding pseudowires to all relevant PE nodes participating in 245 the VPLS. 247 Note that multicast frames are a special case and do not necessarily 248 have to be sent to all VPN members. For simplicity, the default 249 approach of broadcasting multicast frames can be used. Extensions 250 explaining how to interact with 802.1 GMRP protocol, IGMP snooping 251 and static MAC multicast filters will be discussed in a future 252 revision if needed. 254 To forward a frame, a PE must be able to associate a destination MAC 255 address with a pseudowire. It is unreasonable and perhaps impossible 256 to require PEs to statically configure an association of every 257 possible destination MAC address with a pseudowire. Therefore, VPLS- 258 capable PEs must have the capability to dynamically learn MAC 259 addresses on both physical ports and virtual circuits and to forward 260 and replicate packets across both physical ports and pseudowires. 262 5.2. Address Learning 264 Unlike BGP VPNs [BGP-VPN], reachability information does not need to 265 be advertised and distributed via a control plane. Reachability is 266 obtained by standard learning bridge functions in the data plane. 268 As discussed previously, a pseudowire consists of a pair of uni- 269 directional VC LSPs. When a new MAC address is learned on an 270 inbound VC LSP, it needs to be associated with the outbound VC LSP 271 that is part of the same pair. The state of this pseudowire is 272 considered operationally up when both incoming and outgoing VC LSPs 273 are established. Similarly, it is considered operationally down 274 when one of these two VC LSPs is torn down. 276 Standard learning, filtering and forwarding actions, as defined in 277 [802.1D-ORIG], [802.1D-REV] and [802.1Q], are required when a 278 logical link state changes. 280 5.3. Tunnel Topology 282 PE routers typically run an IGP between them, and are assumed to 283 have the capability to establish transport tunnels. Tunnel are set 284 up between PEs to aggregate traffic. Pseudowires are signaled to 285 demultiplex the L2 encapsulated packets that traverse the tunnels. 287 In an Ethernet L2VPN, it becomes the responsibility of the service 288 provider to create the loop free topology. For the sake of 289 simplicity, we define that the topology of a VPLS is a full mesh of 290 tunnels and pseudowires. 292 5.4. Loop free L2 VPN 294 For simplicity, a full mesh of pseudowires is established between 295 PEs. Ethernet bridges, unlike Frame Relay or ATM where the 296 termination point becomes the CE node, have to examine the layer 2 297 fields of the packets to make a switching decision. If the frame is 298 directed to an unknown destination, or is a broadcast or multicast 299 frame, the frame must be flooded. 301 Therefore, if the topology isn't a full mesh, the PE devices may 302 need to forward these frames to other PEs. However, this would 303 require the use of spanning tree protocol to form a loop free 304 topology, that may have characteristics that are undesirable to the 305 provider. The use of a full mesh and split-horizon forwarding 306 obviates the need for a spanning tree protocol. 308 Each PE MUST create a rooted tree to every other PE router that 309 serve the same VPLS. Each PE MUST support a "split-horizon" scheme 310 in order to prevent loops, that is, a PE MUST NOT forward traffic 311 from one pseudowire to another in the same VPLS (since each PE has 312 direct connectivity to all other PEs in the same VPLS). 314 Note that customers are allowed to run STP such as when a customer 315 has "back door" links used to provide redundancy in the case of a 316 failure within the VPLS. In such a case, STP BPDUs are simply 317 tunneled through the provider cloud. 319 6. Discovery 321 Currently, no discovery mechanism has been prescribed for VPLS. 322 There are three potential candidates, [BGP-DISC], [RADIUS-DISC], 323 [LDP-DISC]. 325 7. Control Plane 327 This document describes the control plane functions of Demultiplexor 328 Exchange (signaling of VC labels). Some foundational work in the 329 area of support for multi-homing is laid, although that work is 330 described in a different document [VPLS-BRIDGING]. 332 7.1. LDP Based Signaling of Demultiplexors 334 In order to establish a full mesh of pseudowires, all PEs in a VPLS 335 must have a full mesh of LDP sessions. 337 Once an LDP session has been formed between two PEs, all pseudowires 338 are signaled over this session. 340 In [PWE3-CTRL], the L2 VPN information is carried in a Label Mapping 341 message sent in downstream unsolicited mode, which contains the 342 following VC FEC TLV. VC, C, VC Info Length, Group ID, Interface 343 parameters are as defined in [PWE3-CTRL]. 345 0 1 2 3 346 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 347 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 348 | VC tlv |C| VC Type |VC info Length | 349 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 350 | Group ID | 351 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 352 | VCID | 353 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 | Interface parameters | 355 ~ ~ 356 | | 357 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 359 This document uses the VC type value for Ethernet as defined in 360 [PWE3-CTRL]: 362 VC Type Description 364 0x0001 Frame Relay DLCI 365 0x0002 ATM AAL5 VCC transport 366 0x0003 ATM transparent cell transport 367 0x0004 Ethernet VLAN 368 0x0005 Ethernet 369 0x0006 HDLC 370 0x0007 PPP 371 0x8008 CEM [8] 372 0x0009 ATM VCC cell transport 373 0x000A ATM VPC cell transport 375 VC types 0x0004 and 0x0005 identify pseudowire types that carry VLAN 376 tagged and untagged Ethernet traffic respectively, for point-to- 377 point connectivity. 379 We use the VC type Ethernet with codepoint 0x0005 to identify 380 pseudowires that carry Ethernet traffic for multipoint connectivity. 381 The Ethernet VC Type described below, conforms to the Ethernet VC 382 Type defined in [PWE3-CTRL]. 384 In a VPLS, we use a VCID (to be substituted with a VPNID TLV later, 385 to address extending the scope of a VPLS) to identify an emulated 386 LAN segment. Note that the VCID as specified in [PWE3-CTRL] is a 387 service identifier, identifying a service emulating a point-to-point 388 virtual circuit. In a VPLS, the VCID is a single service 389 identifier. 391 7.2. MAC Address Withdrawal 393 It MAY be desirable to remove or relearn MAC addresses that have 394 been dynamically learned for faster convergence. 396 We introduce an optional MAC TLV that is used to specify a list of 397 MAC addresses that can be removed or relearned using the Address 398 Withdraw Message. 400 The Address Withdraw message with MAC TLVs MAY be supported in order 401 to expedite removal of MAC addresses as the result of a topology 402 change (e.g., failure of the primary link for a dual-homed MTU-s). 403 If a notification message is sent on the backup link (blocked link), 404 which has transitioned into an active state (e.g., similar to 405 Topology Change Notification message of 802.1w RSTP), with a list of 406 MAC entries to be relearned, the PE will update the MAC entries in 407 its FIB for that VPLS instance and send the message to other PEs 408 over the corresponding directed LDP sessions. 410 If the notification message contains an empty list, this tells the 411 receiving PE to remove all the MAC addresses learned for the 412 specified VPLS instance except the ones it learned from the sending 413 PE (MAC address removal is required for all VPLS instances that are 414 affected). Note that the definition of such a notification message 415 is outside the scope of the document, unless it happens to come from 416 an MTU connected to the PE as a spoke. In such a scenario, the 417 message will be just an Address Withdraw message as noted above. 419 7.2.1. MAC TLV 421 MAC addresses to be relearned can be signaled using an LDP Address 422 Withdraw Message that contains a new TLV, the MAC TLV. Its format 423 is described below. The encoding of a MAC TLV address is the 6-byte 424 MAC address specified by IEEE 802 documents [g-ORIG] [802.1D-REV]. 426 0 1 2 3 427 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 428 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 429 |U|F| Type | Length | 430 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 431 | MAC address #1 | 432 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 433 | MAC address #n | 434 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 436 U bit 437 Unknown bit. This bit MUST be set to 0. If the MAC address 438 format is not understood, then the TLV is not understood, and MUST 439 be ignored. 441 F bit 442 Forward bit. This bit MUST be set to 0. Since the LDP 443 mechanism used here is Targeted, the TLV MUST NOT be forwarded. 445 Type 446 Type field. This field MUST be set to 0x0404 (subject to IANA 447 approval). This identifies the TLV type as MAC TLV. 449 Length 450 Length field. This field specifies the total length of the MAC 451 addresses in the TLV. 453 MAC Address 454 The MAC address(es) being removed. 456 The LDP Address Withdraw Message contains a FEC TLV (to identify the 457 VPLS in consideration), a MAC Address TLV and optional parameters. 458 No optional parameters have been defined for the MAC Address 459 Withdraw signaling. 461 7.2.2. Address Withdraw Message Containing MAC TLV 463 When MAC addresses are being removed or relearned explicitly, e.g., 464 the primary link of a dual-homed MTU-s has failed, an Address 465 Withdraw Message can be sent with the list of MAC addresses to be 466 relearned. 468 The processing for MAC TLVs received in an Address Withdraw Message 469 is: 470 For each MAC address in the TLV: 471 - Relearn the association between the MAC address and the 472 interface/pseudowire over which this message is received 473 - Send the same message to all other PEs over the corresponding 474 directed LDP sessions. 476 For an Address Withdraw message with empty list: 477 - Remove all the MAC addresses associated with the VPLS instance 478 (specified by the FEC TLV) except the MAC addresses learned 479 over this link (over the pseudowire associated with the 480 signaling link over which the message is received) 481 - Send the same message to all other PEs over the corresponding 482 directed LDP sessions. 484 The scope of a MAC TLV is the VPLS specified in the FEC TLV in the 485 Address Withdraw Message. The number of MAC addresses can be 486 deduced from the length field in the TLV. 488 Further descriptions of how to deal with failures expeditiously with 489 different configurations will be described in other documents, such 490 as [VPLS-BRIDGING]. 492 8. Data Forwarding on an Ethernet VC Type 494 This section describes the dataplane behavior on an Ethernet VPLS 495 pseudowire. While the encapsulation is similar to that described in 496 [PWE3-ETHERNET], the NSP functions of stripping the service- 497 delimiting tag, and using a "normalized" Ethernet packet are 498 described. 500 8.1. VPLS Encapsulation actions 502 In a VPLS, a customer Ethernet packet without preamble is 503 encapsulated with a header as defined in [PWE3-ETHERNET]. A 504 customer Ethernet packet is defined as follows: 506 - If the packet, as it arrives at the PE, has an encapsulation 507 that is used by the local PE as a service delimiter, i.e., to 508 identify the customer and/or the particular service of that 509 customer, then that encapsulation is stripped before the packet 510 is sent into the VPLS. As the packet exits the VPLS, the 511 packet may have a service-delimiting encapsulation inserted. 513 - If the packet, as it arrives at the PE, has an encapsulation 514 that is not service delimiting, then it is a customer packet 515 whose encapsulation should not be modified by the VPLS. This 516 covers, for example, a packet that carries customer specific 517 VLAN-Ids that the service provider neither knows about nor 518 wants to modify. 520 As an application of these rules, a customer packets may arrive at a 521 customer-facing port with a VLAN tag that identifies the customer's 522 VPLS instance. That tag would be stripped before it is encapsulated 523 in the VPLS. At egress, the packet may be tagged again, if a 524 service-delimiting tag is used, or it may be untagged if none is 525 used. 527 Likewise, if a customer packet arrives at a customer-facing port 528 over an ATM VC that identifies the customer's VPLS instance, then 529 the ATM encapsulation is removed before the packet is passed into 530 the VPLS. 532 Contrariwise, if a customer packet arrives at a customer-facing port 533 with a VLAN tag that identifies a VLAN domain in the customer L2 534 network, then the tag is not modified or stripped, as it belongs 535 with the rest of the customer frame. 537 By following the above rules, the Ethernet packet that traverses a 538 VPLS is always a customer Ethernet packet. Note that the two 539 actions, at ingress and egress, of dealing with service delimiters 540 are local actions that neither PE has to signal to the other. They 541 allow, for example, a mix-and-match of VLAN tagged and untagged 542 services at either end, and do not carry across a VPLS a VLAN tag 543 that has local significance only. The service delimiter may be an 544 MPLS label also, whereby an Ethernet pseudowire given by [PWE3- 545 ETHERNET] can serve as the access side connection into a PE. An 546 RFC1483 PVC encapsulation could be another service delimiter. By 547 limiting the scope of locally significant encapsulations to the 548 edge, hierarchical VPLS models can be developed that provide the 549 capability to network-engineer VPLS deployments, as described below. 551 8.1.1. VPLS Learning actions 553 Learning is done based on the customer Ethernet packet, as defined 554 above. The Forwarding Information Base (FIB) keeps track of the 555 mapping of customer Ethernet packet addressing and the appropriate 556 pseudowire to use. We define two modes of learning: qualified and 557 unqualified learning. However, the model followed in this VPLS 558 document is the unqualified learning model. 560 In unqualified learning, all the customer VLANs are handled by a 561 single VPLS, which means they all share a single broadcast domain 562 and a single MAC address space. This means that MAC addresses need 563 to be unique and non-overlapping among customer VLANs or else they 564 cannot be differentiated within the VPLS instance and this can 565 result in loss of customer frames. An application of unqualified 566 learning is port-based VPLS service for a given customer (e.g., 567 customer with non-multiplexed UNI interface where all the traffic on 568 a physical port, which may include multiple customer VLANs, is 569 mapped to a single VPLS instance). 571 In qualified learning, each customer VLAN is assigned to its own 572 VPLS instance, which means each customer VLAN has its own broadcast 573 domain and MAC address space. Therefore, in qualified learning, MAC 574 addresses among customer VLANs may overlap with each other, but they 575 will be handled correctly since each customer VLAN has its own FIB , 576 i.e., each customer VLAN has its own MAC address space. Since VPLS 577 broadcasts multicast frames, qualified learning offers the advantage 578 of limiting the broadcast scope to a given customer VLAN. 580 9. Operation of a VPLS 582 We show here an example of how a VPLS works. The following 583 discussion uses the figure below, where a VPLS has been set up 584 between PE1, PE2 and PE3. 586 Initially, the VPLS is set up so that PE1, PE2 and PE3 have a full- 587 mesh of Ethernet pseudowires. The VPLS instance is assigned a 588 unique VCID. 590 For the above example, say PE1 signals VC Label 102 to PE2 and 103 591 to PE3, and PE2 signals VC Label 201 to PE1 and 203 to PE3. 593 Assume a packet from A1 is bound for A2. When it leaves CE1, say it 594 has a source MAC address of M1 and a destination MAC of M2. If PE1 595 does not know where M2 is, it will multicast the packet to PE2 and 596 PE3. When PE2 receives the packet, it will have an inner label of 597 201. PE2 can conclude that the source MAC address M1 is behind PE1, 598 since it distributed the label 201 to PE1. It can therefore 599 associate MAC address M1 with VC Label 102. 601 ----- 602 / A1 \ 603 ---- ----CE1 | 604 / \ -------- ------- / | | 605 | A2 CE2- / \ / PE1 \ / 606 \ / \ / \---/ \ ----- 607 ---- ---PE2 | 608 | Service Provider Network | 609 \ / \ / 610 ----- PE3 / \ / 611 |Agg|_/ -------- ------- 612 -| | 613 ---- / ----- ---- 614 / \/ \ / \ CE = Customer Edge Router 615 | A3 CE3 --C4 A4 | PE = Provider Edge Router 616 \ / \ / Agg = Layer 2 Aggregation 617 ---- ---- 619 9.1. MAC Address Aging 621 PEs that learn remote MAC addresses need to have an aging mechanism 622 to remove unused entries associated with a VC Label. This is 623 important both for conservation of memory as well as for 624 administrative purposes. For example, if a customer site A is shut 625 down, eventually, the other PEs should unlearn A's MAC address. 627 As packets arrive, MAC addresses are remembered. The aging timer 628 for MAC address M SHOULD be reset when a packet is received with 629 source MAC address M. 631 10. A Hierarchical VPLS Model 633 The solution described above requires a full mesh of tunnel LSPs 634 between all the PE routers that participate in the VPLS service. 635 For each VPLS service, n*(n-1)/2 pseudowires must be setup between 636 the PE routers. While this creates signaling overhead, the real 637 detriment to large scale deployment is the packet replication 638 requirements for each provisioned VCs on a PE router. Hierarchical 639 connectivity, described in this document reduces signaling and 640 replication overhead to allow large scale deployment. 642 In many cases, service providers place smaller edge devices in 643 multi-tenant buildings and aggregate them into a PE device in a 644 large Central Office (CO) facility. In some instances, standard IEEE 645 802.1q (Dot 1Q) tagging techniques may be used to facilitate mapping 646 CE interfaces to PE VPLS access points. 648 It is often beneficial to extend the VPLS service tunneling 649 techniques into the MTU (multi-tenant unit) domain. This can be 650 accomplished by treating the MTU device as a PE device and 651 provisioning pseudowires between it and every other edge, as an 652 basic VPLS. An alternative is to utilize [PWE3-ETHERNET] 653 pseudowires or Q-in-Q logical interfaces between the MTU and 654 selected VPLS enabled PE routers. Q-in-Q encapsulation is another 655 form of L2 tunneling technique, which can be used in conjunction 656 with MPLS signaling as will be described later. The following two 657 sections focus on this alternative approach. The VPLS core 658 pseudowires (Hub) are augmented with access pseudowires (Spoke) to 659 form a two tier hierarchical VPLS (H-VPLS). 661 Spoke pseudowires may be implemented using any L2 tunneling 662 mechanism, expanding the scope of the first tier to include non- 663 bridging VPLS PE routers. The non-bridging PE router would extend a 664 Spoke pseudowire from a Layer-2 switch that connects to it, through 665 the service core network, to a bridging VPLS PE router supporting 666 Hub pseudowires. We also describe how VPLS-challenged nodes and 667 low-end CEs without MPLS capabilities may participate in a 668 hierarchical VPLS. 670 10.1. Hierarchical connectivity 672 This section describes the hub and spoke connectivity model and 673 describes the requirements of the bridging capable and non-bridging 674 MTU devices for supporting the spoke connections. 676 For rest of this discussion we will refer to a bridging capable MTU 677 device as MTU-s and a non-bridging capable PE device as PE-r. A 678 routing and bridging capable device will be referred to as PE-rs. 680 10.1.1. Spoke connectivity for bridging-capable devices 682 As shown in the figure below, consider the case where an MTU-s 683 device has a single connection to the PE-rs device placed in the CO. 684 The PE-rs devices are connected in a basic VPLS full mesh. For each 685 VPLS service, a single spoke pseudowire is set up between the MTU-s 686 and the PE-rs based on [PWE3-CTRL]. Unlike traditional pseudowires 687 that terminate on a physical (or a VLAN-tagged logical) port at each 688 end, the spoke pseudowire terminates on a virtual bridge instance on 689 the MTU-s and the PE-rs devices. 690 PE2-rs 691 ------ 692 / \ 693 | -- | 694 | / \ | 695 CE-1 | \B / | 696 \ \ -- / 697 \ /------ 698 \ MTU-s PE1-rs / | 699 \ ------ ------ / | 700 / \ / \ / | 701 | \ -- | VC-1 | -- |---/ | 702 | / \--|- - - - - - - - - - - |--/ \ | | 703 | \B / | | \B / | | 704 \ /-- / \ -- / ---\ | 705 /----- ------ \ | 706 / \ | 707 ---- \ ------ 708 |Agg | / \ 709 ---- | -- | 710 / \ | / \ | 711 CE-2 CE-3 | \B / | 712 \ -- / 713 MTU-s = Bridging capable MTU ------ 714 PE-rs = VPLS capable PE PE3-rs 716 -- 717 / \ 718 \B / = Virtual VPLS(Bridge)Instance 719 -- 720 Agg = Layer-2 Aggregation 722 The MTU-s device and the PE-rs device treat each spoke connection 723 like an access port of the VPLS service. On access ports, the 724 combination of the physical port and/or the VLAN tag is used to 725 associate the traffic to a VPLS instance while the pseudowire tag 726 (e.g., VC label) is used to associate the traffic from the virtual 727 spoke port with a VPLS instance, followed by a standard L2 lookup to 728 identify which customer port the frame needs to be sent to. 730 10.1.1.1. MTU-s Operation 732 MTU-s device is defined as a device that supports layer-2 switching 733 functionality and does all the normal bridging functions of learning 734 and replication on all its ports, including the virtual spoke port. 735 Packets to unknown destination are replicated to all ports in the 736 service including the virtual spoke port. Once the MAC address is 737 learned, traffic between CE1 and CE2 will be switched locally by the 738 MTU-s device saving the link capacity of the connection to the PE- 739 rs. Similarly traffic between CE1 or CE2 and any remote destination 740 is switched directly on to the spoke connection and sent to the PE- 741 rs over the point-to-point pseudowire. 743 Since the MTU-s is bridging capable, only a single pseudowire is 744 required per VPLS instance for any number of access connections in 745 the same VPLS service. This further reduces the signaling overhead 746 between the MTU-s and PE-rs. 748 If the MTU-s is directly connected to the PE-rs, other encapsulation 749 techniques such as Q-in-Q can be used for the spoke connection 750 pseudowire. However, to maintain a uniform end-to-end control plane 751 based on MPLS signaling, [PWE3-CTRL] can be used for distribution of 752 pseudowire tags (e.g., Q-in-Q tags or pseudowire labels) between 753 MTU-s and PE-rs. 755 10.1.1.2. PE-rs Operation 757 The PE-rs device is a device that supports all the bridging 758 functions for VPLS service and supports the routing and MPLS 759 encapsulation, i.e. it supports all the functions described in 760 [VPLS]. 762 The operation of PE-rs is independent of the type of device at the 763 other end of the spoke pseudowire. Thus, the spoke pseudowire from 764 the PE-r is treated as a virtual port and the PE-rs device will 765 switch traffic between the spoke pseudowire, hub pseudowires, and 766 access ports once it has learned the MAC addresses. 768 10.1.2. Advantages of spoke connectivity 770 Spoke connectivity offers several scaling and operational advantages 771 for creating large scale VPLS implementations, while retaining the 772 ability to offer all the functionality of the VPLS service. 774 - Eliminates the need for a full mesh of tunnels and full mesh of 775 pseudowires per service between all devices participating in the 776 VPLS service. 777 - Minimizes signaling overhead since fewer pseudowires are required 778 for the VPLS service. 779 - Segments VPLS nodal discovery. MTU-s needs to be aware of only 780 the PE-rs node although it is participating in the VPLS service 781 that spans multiple devices. On the other hand, every VPLS PE-rs 782 must be aware of every other VPLS PE-rs device and all of it�s 783 locally connected MTU-s and PE-r. 784 - Addition of other sites requires configuration of the new MTU-s 785 device but does not require any provisioning of the existing MTU-s 786 devices on that service. 787 - Hierarchical connections can be used to create VPLS service that 788 spans multiple service provider domains. This is explained in a 789 later section. 791 10.1.3. Spoke connectivity for non-bridging devices 793 In some cases, a bridging PE-rs device may not be deployed in a CO 794 or a multi-tenant building while a PE-r might already be deployed. 795 If there is a need to provide VPLS service from the CO where the PE- 796 rs device is not available, the service provider may prefer to use 797 the PE-r device in the interim. In this section, we explain how a 798 PE-r device that does not support any of the VPLS bridging 799 functionality can participate in the VPLS service. 801 As shown in this figure, the PE-r device creates a point-to-point 802 tunnel LSP to a PE-rs device. Then for every access port that needs 804 PE2-rs 805 ------ 806 / \ 807 | -- | 808 | / \ | 809 CE-1 | \B / | 810 \ \ -- / 811 \ /------ 812 \ PE-r PE1-rs / | 813 \ ------ ------ / | 814 / \ / \ / | 815 | \ | VC-1 | -- |---/ | 816 | ------|- - - - - - - - - - - |--/ \ | | 817 | -----|- - - - - - - - - - - |--\B / | | 818 \ / / \ -- / ---\ | 819 ------ ------ \ | 820 / \ | 821 ---- \------ 822 | Agg| / \ 823 ---- | -- | 824 / \ | / \ | 825 CE-2 CE-3 | \B / | 826 \ -- / 827 ------ 828 PE3-rs 830 to participate in a VPLS service, the PE-r device creates a point- 831 to-point [PWE3-ETHERNET] pseudowire that terminates on the physical 832 port at the PE-r and terminates on the virtual bridge instance of 833 the VPLS service at the PE-rs. 835 10.1.3.1. PE-r Operation 837 The PE-r device is defined as a device that supports routing but 838 does not support any bridging functions. However, it is capable of 839 setting up [PWE3-ETHERNET] pseudowires between itself and the PE-rs. 840 For every port that is supported in the VPLS service, a [PWE3- 841 ETHERNET] pseudowire is setup from the PE-r to the PE-rs. Once the 842 pseudowires are setup, there is no learning or replication function 843 required on part of the PE-r. All traffic received on any of the 844 access ports is transmitted on the pseudowire. Similarly all 845 traffic received on a pseudowire is transmitted to the access port 846 where the pseudowire terminates. Thus traffic from CE1 destined for 847 CE2 is switched at PE-rs and not at PE-r. 849 This approach adds more overhead than the bridging capable (MTU-s) 850 spoke approach since a pseudowire is required for every access port 851 that participates in the service versus a single pseudowire required 852 per service (regardless of access ports) when a MTU-s type device is 853 used. However, this approach offers the advantage of offering a 854 VPLS service in conjunction with a routed internet service without 855 requiring the addition of new MTU device. 857 10.2. Redundant Spoke Connections 859 An obvious weakness of the hub and spoke approach described thus far 860 is that the MTU device has a single connection to the PE-rs device. 861 In case of failure of the connection or the PE-rs device, the MTU 862 device suffers total loss of connectivity. 864 In this section we describe how the redundant connections can be 865 provided to avoid total loss of connectivity from the MTU device. 866 The mechanism described is identical for both, MTU-s and PE-r type 867 of devices 869 10.2.1. Dual-homed MTU device 871 To protect from connection failure of the pseudowire or the failure 872 of the PE-rs device, the MTU-s device or the PE-r is dual-homed into 873 two PE-rs devices, as shown in figure-3. The PE-rs devices must be 874 part of the same VPLS service instance. 876 An MTU-s device will setup two [PWE3-ETHERNET] pseudowires (one each 877 to PE-rs1 and PE-rs2) for each VPLS instance. One of the two 878 pseudowires is designated as primary and is the one that is actively 879 used under normal conditions, while the second pseudowire is 880 designated as secondary and is held in a standby state. The MTU 881 device negotiates the pseudowire labels for both the primary and 882 secondary pseudowires, but does not use the secondary pseudowire 883 unless the primary pseudowire fails. Since only one link is active 884 at a given time, a loop does not exist and hence 802.1D spanning 885 tree is not required. 887 PE2-rs 888 ------ 889 / \ 890 | -- | 891 | / \ | 892 CE-1 | \B / | 893 \ \ -- / 894 \ /------ 895 \ MTU-s PE1-rs / | 896 \------ ------ / | 897 / \ / \ / | 898 | -- | Primary PW | -- |---/ | 899 | / \--|- - - - - - - - - - - |--/ \ | | 900 | \B / | | \B / | | 901 \ -- \/ \ -- / ---\ | 902 ------\ ------ \ | 903 / \ \ | 904 / \ \ ------ 905 / \ / \ 906 CE-2 \ | -- | 907 \ Secondary PW | / \ | 908 - - - - - - - - - - - - - - - - - |-\B / | 909 \ -- / 910 ------ 911 PE3-rs 913 10.2.2. Failure detection and recovery 915 The MTU-s device controls the usage of the pseudowires to the PE-rs 916 nodes. Since LDP signaling is used to negotiate the pseudowire 917 labels, the hello messages used for the LDP session can be used to 918 detect failure of the primary pseudowire. 920 Upon failure of the primary pseudowire, MTU-s device immediately 921 switches to the secondary pseudowire. At this point the PE3-rs 922 device that terminates the secondary pseudowire starts learning MAC 923 addresses on the spoke pseudowire. All other PE-rs nodes in the 924 network think that CE-1 and CE-2 are behind PE1-rs and may continue 925 to send traffic to PE1-rs until they learn that the devices are now 926 behind PE3-rs. The relearning process can take a long time and may 927 adversely affect the connectivity of higher level protocols from CE1 928 and CE2. To enable faster convergence, the PE3-rs device where the 929 secondary pseudowire got activated may send out a flush message, 930 using the MAC TLV as defined in Section 6, to PE1-rs, who relays it 931 to all other PE-rs devices participating in the VPLS service. Upon 932 receiving the message, all PE-rs nodes flush the MAC addresses 933 associated with that VPLS instance. 935 10.3. Multi-domain VPLS service 937 Hierarchy can also be used to create a large scale VPLS service 938 within a single domain or a service that spans multiple domains 939 without requiring full mesh connectivity between all VPLS capable 940 devices. Two fully meshed VPLS networks are connected together 941 using a single LSP tunnel between the VPLS gateway devices. A 942 single spoke pseudowire is setup per VPLS service to connect the two 943 domains together. The VPLS gateway device joins two VPLS services 944 together to form a single multi-domain VPLS service. The 945 requirements and functionality required from a VPLS gateway device 946 will be explained in a future version of this document. 948 11. Hierarchical VPLS model using Ethernet Access Network 950 In the previous section, a two-tier hierarchical model that consists 951 of hub-and-spoke topology between MTU-s devices and PE-rs devices and 952 a full-mesh topology among PE-rs devices was discussed. In this 953 section the two-tier hierarchical model is expanded to include an 954 Ethernet access network. This model retains the hierarchical 955 architecture discussed previously in that it leverages the full-mesh 956 topology among PE-rs devices; however, no restriction is imposed on 957 the topology of the Ethernet access network (e.g., the topology 958 between MTU-s and PE-rs devices are not restricted to hub and spoke). 960 The motivation for an Ethernet access network is that Ethernet-based 961 networks are currently deployed by some service providers to offer 962 VPLS services to their customers. Therefore, it is important to 963 provide a mechanism that allows these networks to integrate with an 964 IP or MPLS core to provide scalable VPLS services. 966 One approach of tunneling a customer's Ethernet traffic via an 967 Ethernet access network is to add an additional VLAN tag to the 968 customer's data (which may be either tagged or untagged). The 969 additional tag is referred to as Provider's VLAN (P-VLAN). Inside the 970 provider's network each P-VLAN designates a customer or more 971 specifically a VPLS instance for that customer. Therefore, there is a 972 one to one correspondence between a P-VLAN and a VPLS instance. 974 In this model, the MTU-S device needs to have the capability of 975 adding the additional P-VLAN tag for non-multiplexed customer UNI 976 port where customer VLANs are not used as service delimiter. If 977 customer VLANs need to be treated as service delimiter (e.g., 978 customer UNI port is a multiplexed port), then the MTU-s needs to 979 have the additional capability of translating a customer VLAN (C- 980 VLAN) to a P-VLAN in order to resolve overlapping VLAN-ids used by 981 different customers. Therefore, the MTU-s device in this model can be 982 considered as a typical bridge with this additional UNI capability. 984 The PE-rs device needs to be able to perform bridging functionality 985 over the standard Ethernet ports toward the access network as well as 986 over the pseudowires toward the network core. The set of pseudowires 987 that corresponds to a VPLS instance would look just like a P-VLAN to 988 the bridge portion of the PE-rs and that is why sometimes it is 989 referred to as Emulated VLAN. In this model the PE-rs may need to run 990 STP protocol in addition to split-horizon. Split horizon is run over 991 MPLS-core; whereas, STP is run over the access network to accommodate 992 any arbitrary access topology. In this model, the PE-rs needs to map 993 a P-VLAN to a VPLS-instance and its associated pseudowires and vise 994 versa. 996 The details regarding bridge operation for MTU-s and PE-rs (e.g., 997 encapsulation format for QinQ messages, customer�s Ethernet control 998 protocol handling, etc.) are outside of the scope of this document 999 and they are covered in [802.1ad]. However, the relevant part is the 1000 interaction between the bridge module and the MPLS/IP pseudowires in 1001 the PE-rs device. 1003 11.1. Scalability 1005 Given that each P-VLAN corresponds to a VPLS instance, one may think 1006 that the total number of VPLS instances supported is limited to 4K. 1007 However, the 4K limit applies only to each Ethernet access network 1008 (Ethernet island) and not to the entire network. The SP network, in 1009 this model, consists of a core MPLS/IP network that connects many 1010 Ethernet islands. Therefore, the number of VPLS instances can scale 1011 accordingly with the number of Ethernet islands (a metro region can 1012 be represented by one or more islands). Each island may consist of 1013 many MTU-s devices, several aggregators, and one or more PE-rs 1014 devices. The PE-rs devices enable a P-VLAN to be extended from one 1015 island to others using a set of pseudowires (associated with that 1016 VPLS instance) and providing a loop free mechanism across the core 1017 network through split-horizon. Since a P-VLAN serves as a service 1018 delimiter within the provider's network, it does not get carried over 1019 the pseudowires and furthermore the mapping between P-VLAN and the 1020 pseudowires is a local matter. This means a VPLS instance can be 1021 represented by different P-VLAN in different Ethernet islands and 1022 furthermore each island can support 4K VPLS instances independent 1023 from one another. 1025 11.2. Dual Homing and Failure Recovery 1027 In this model, an MTU-s can be dual or triple homed to different 1028 devices (aggregators and/or PE-rs devices). The failure protection 1029 for access network nodes and links can be provided through running 1030 MSTP in each island. The MSTP of each island is independent from 1031 other islands and do not interact with each other. If an island has 1032 more than one PE-rs, then a dedicated full-mesh of pseudowires is 1033 used among these PE-rs devices for carrying the SP BPDU packets for 1034 that island. On a per P-VLAN basis, the MSTP will designate a single 1035 PE-rs to be used for carrying the traffic across the core. The loop- 1036 free protection through the core is performed using split-horizon and 1037 the failure protection in the core is performed through standard 1038 IP/MPLS re-routing. 1040 12. Significant Modifications 1042 Between rev 04 and this one, these are the changes: 1044 o minor revisions of text 1045 o cleanup of use of MPLS LSPs for tunnels 1046 o clearly states qualified learning is out of scope for current 1047 model 1048 o corrected MAC TLV description 1050 13. Acknowledgments 1052 We wish to thank Joe Regan, Kireeti Kompella, Anoop Ghanwani, Joel 1053 Halpern, Rick Wilder, Jim Guichard, Steve Phillips, Norm Finn, Matt 1054 Squire, Muneyoshi Suzuki, Waldemar Augustyn, and Eric Rosen for 1055 their valuable feedback. In addition, we would like to thank Rajiv 1056 Papneja (ISOCORE), Winston Liu (ISOCORE), and Charlie Hundall 1057 (Extreme) for identifying issues with the draft in the course of the 1058 interoperability tests. 1060 14. Security Considerations 1062 Security issues resulting from this draft will be discussed in 1063 greater depth at a later point. It is recommended in [RFC3036] that 1064 LDP security (authentication) methods be applied. This would 1065 prevent unauthorized participation by a PE in a VPLS. Traffic 1066 separation for a VPLS is effected by using VC labels. However, for 1067 additional levels of security, the customer MAY deploy end-to-end 1068 security, which is out of the scope of this draft. In addition, the 1069 L2FRAME] document describes security issues in greater depth. 1071 15. Intellectual Property Considerations 1073 This document is being submitted for use in IETF standards 1074 discussions. 1076 16. Full Copyright Statement 1078 Copyright (C) The Internet Society (2001). All Rights Reserved. 1079 This document and translations of it may be copied and furnished to 1080 others, and derivative works that comment on or otherwise explain it 1081 or assist in its implementation may be prepared, copied, published 1082 and distributed, in whole or in part, without restriction of any 1083 kind, provided that the above copyright notice and this paragraph 1084 are included on all such copies and derivative works. However, this 1085 document itself may not be modified in any way, such as by removing 1086 the copyright notice or references to the Internet Society or other 1087 Internet organizations, except as needed for the purpose of 1088 developing Internet standards in which case the procedures for 1089 copyrights defined in the Internet Standards process must be 1090 followed, or as required to translate it into languages other than 1091 English. 1093 The limited permissions granted above are perpetual and will not be 1094 revoked by the Internet Society or its successors or assigns. 1096 This document and the information contained herein is provided on an 1097 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 1098 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 1099 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 1100 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 1101 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1103 17. References 1105 [PWE3-ETHERNET] "Encapsulation Methods for Transport of Ethernet 1106 Frames Over IP/MPLS Networks", draft-ietf-pwe3-ethernet-encap- 1107 02.txt, Work in progress, February 2003. 1109 [PWE3-CTRL] "Transport of Layer 2 Frames Over MPLS", draft-ietf- 1110 pwe3-control-protocol-02.txt, Work in progress, February 2003. 1112 [802.1D-ORIG] Original 802.1D - ISO/IEC 10038, ANSI/IEEE Std 802.1D- 1113 1993 "MAC Bridges". 1115 [802.1D-REV] 802.1D - "Information technology - Telecommunications 1116 and information exchange between systems - Local and metropolitan 1117 area networks - Common specifications - Part 3: Media Access Control 1118 (MAC) Bridges: Revision. This is a revision of ISO/IEC 10038: 1993, 1119 802.1j-1992 and 802.6k-1992. It incorporates P802.11c, P802.1p and 1120 P802.12e." ISO/IEC 15802-3: 1998. 1122 [802.1Q] 802.1Q - ANSI/IEEE Draft Standard P802.1Q/D11, "IEEE 1123 Standards for Local and Metropolitan Area Networks: Virtual Bridged 1124 Local Area Networks", July 1998. 1126 [BGP-VPN] Rosen and Rekhter, "BGP/MPLS VPNs". draft-ietf-ppvpn- 1127 rfc2547bis-04.txt, Work in Progress, May 2003. 1129 [RFC3036] "LDP Specification", L. Andersson, et al. RFC 3036. 1130 January 2001. 1132 [RADIUS-DISC] " Using Radius for PE-Based VPN Discovery", Juha 1133 Heinanen, draft-heinanen-radius-pe-discovery-04.txt, Work in 1134 Progress, June 2003. 1136 [BGP-DISC] "Using BGP as an Auto-Discovery Mechanism for Network- 1137 based VPNs", Ould-Brahim, et. al., draft-ietf-ppvpn-bgpvpn-auto- 1138 05.txt, Work in Progress, May 2003. 1140 [LDP-DISC] "Discovering Nodes and Services in a VPLS Network", O. 1141 Stokes et al, draft-stokes-ppvpn-vpls-discover-00.txt, Work in 1142 Progress, June 2002. 1144 [VPLS-BRIDGING] "Bridging and VPLS", draft-finn-ppvpn-bridging-vpls- 1145 00.txt, Work in Progress, June 2002. 1147 [L2VPN-SIG] "LDP-based Signaling for L2VPNs", draft-rosen-ppvpn-l2- 1148 signaling-03.txt, Work in Progress, May 2003. 1150 [L2FRAME] "L2VPN Framework", draft-ietf-ppvpn-l2-framework-03, Work 1151 in Progress, February 2003. 1153 [L2VPN-REQ] "Service Requirements for Layer 2 Provider Provisioned 1154 Virtual Private Networks", draft-ietf-ppvpn-l2vpn-requirements- 1155 00.txt, Work in Progress, May 2003. 1157 [802.1ad] "IEEE standard for Provider Bridges", Work in Progress, 1158 December 2002. 1160 18. Authors' Addresses 1162 Marc Lasserre 1163 Riverstone Networks 1164 Email: marc@riverstonenet.com 1166 Vach Kompella 1167 TiMetra Networks 1168 274 Ferguson Dr. 1169 Mountain View, CA 94043 1170 Email: vkompella@timetra.com 1172 Sunil Khandekar 1173 TiMetra Networks 1174 274 Ferguson Dr. 1175 Mountain View, CA 94043 1176 Email: sunil@timetra.com 1178 Nick Tingle 1179 TiMetra Networks 1180 274 Ferguson Dr. 1181 Mountain View, CA 94043 1182 Email: nick@timetra.com 1183 Ali Sajassi 1184 Cisco Systems, Inc. 1185 170 West Tasman Drive 1186 San Jose, CA 95134 1187 Email: sajassi@cisco.com 1189 Loa Andersson 1190 Email: loa@pi.se 1192 Pascal Menezes 1193 Email: pascalm1@yahoo.com 1195 Andrew Smith 1196 Consultant 1197 Email: ah_smith@pacbell.net 1199 Giles Heron 1200 PacketExchange Ltd. 1201 Email: giles@packetexchange.net 1203 Juha Heinanen 1204 TutPro 1205 Email: jh@tutpro.com 1207 Tom S. C. Soon 1208 SBC Technology Resources Inc. 1209 Email: sxsoon@tri.sbc.com 1211 Yetik Serbest 1212 SBC Communications 1213 serbest@tri.sbc.com 1215 Eric Puetz 1216 SBC Communications 1217 puetz@tri.sbc.com 1219 Ron Haberman 1220 Masergy Inc. 1221 Email: ronh@masergy.com 1223 Luca Martini 1224 Level 3 Communications, LLC. 1225 Email: luca@level3.net 1227 Rob Nath 1228 Riverstone Networks 1229 Email: rnath@riverstonenet.com