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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 1090 looks like a reference -- Missing reference section? 'PWE3-ETHERNET' on line 1086 looks like a reference -- Missing reference section? 'L2VPN-REQ' on line 1133 looks like a reference -- Missing reference section? 'BGP-VPN' on line 1107 looks like a reference -- Missing reference section? 'BGP-DISC' on line 1116 looks like a reference -- Missing reference section? 'DNS-DISC' on line 1113 looks like a reference -- Missing reference section? 'LDP-DISC' on line 1120 looks like a reference -- Missing reference section? 'VPLS-BRIDGING' on line 1124 looks like a reference -- Missing reference section? '8' on line 375 looks like a reference -- Missing reference section? 'VPLS' on line 745 looks like a reference -- Missing reference section? 'RFC3036' on line 1110 looks like a reference -- Missing reference section? 'L2VPN-SIG' on line 1127 looks like a reference -- Missing reference section? 'L2FRAME' on line 1130 looks like a reference Summary: 8 errors (**), 0 flaws (~~), 3 warnings (==), 15 comments (--). 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-lasserre-vkompella-ppvpn-vpls-04.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: September 2003 March 2003 33 Virtual Private LAN Services over MPLS 34 draft-lasserre-vkompella-ppvpn-vpls-04.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......................................11 126 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 serve as Label Edge 190 Routers (LERs) on an MPLS network that is VPLS capable. The behavior 191 of transit Label Switch Routers (LSRs) that are considered a part of 192 MPLS network is not discussed. The MPLS network provides a number of 193 Label Switch Paths (LSPs) that form the basis for connections 194 between LERs attached to the same MPLS network. The resulting set of 195 interconnected LERs forms a private MPLS VPN where each LSP is 196 uniquely identified at each MPLS interface by a label. 198 5. Topological Model for VPLS 200 An interface participating in a VPLS must be able to flood, forward, 201 and filter ethernet frames. 203 +----+ +----+ 204 + C1 +---+ ........................... +---| C1 | 205 +----+ | . . | +----+ 206 Site A | +----+ +----+ | Site B 207 +---| PE |---- MPLS Cloud ----| PE |---+ 208 +----+ | +----+ 209 . | . 210 . +----+ . 211 ..........| PE |........... 212 +----+ ^ 213 | | 214 | +-- Emulated LAN 215 +----+ 216 | C1 | 217 +----+ 218 Site C 220 The set of PE devices interconnected via pseudowires appears as a 221 single emulated LAN to customer C1. Each PE device will learn remote 222 MAC address to pseudowire associations and will also learn directly 223 attached MAC addresses on customer facing ports. 225 We note here that while this document shows specific examples using 226 MPLS transport tunnels, other tunnels that can be used by pseudo- 227 wires, e.g., GRE, L2TP, IPSEC, etc., can also be used, as long as 228 the originating PE can be identified, since this is used in the MAC 229 learning process. 231 The scope of the VPLS lies within the PEs in the service provider 232 network, highlighting the fact that apart from customer service 233 delineation, the form of access to a customer site is not relevant 234 to the VPLS [L2VPN-REQ]. 236 The PE device is typically an edge router capable of running a 237 signaling protocol and/or routing protocols to set up pseudowires. 238 In addition, it is capable of setting up transport tunnels to other 239 PEs and deliver traffic over a pseudowire. 241 5.1. Flooding and Forwarding 243 One of attributes of an Ethernet service is that all broadcast and 244 destination unknown MAC addresses are flooded to all ports. To 245 achieve flooding within the service provider network, all address 246 unknown unicast, broadcast and multicast frames are flooded over the 247 corresponding pseudowires to all relevant PE nodes participating in 248 the VPLS. 250 Note that multicast frames are a special case and do not necessarily 251 have to be sent to all VPN members. For simplicity, the default 252 approach of broadcasting multicast frames can be used. Extensions 253 explaining how to interact with 802.1 GMRP protocol, IGMP snooping 254 and static MAC multicast filters will be discussed in a future 255 revision if needed. 257 To forward a frame, a PE must be able to associate a destination MAC 258 address with a pseudowire. It is unreasonable and perhaps impossible 259 to require PEs to statically configure an association of every 260 possible destination MAC address with a pseudowire. Therefore, VPLS- 261 capable PEs must have the capability to dynamically learn MAC 262 addresses on both physical ports and virtual circuits and to forward 263 and replicate packets across both physical ports and pseudowires. 265 5.2. Address Learning 267 Unlike BGP VPNs [BGP-VPN], reachability information does not need to 268 be advertised and distributed via a control plane. Reachability is 269 obtained by standard learning bridge functions in the data plane. 271 As discussed previously, a pseudowire consists of a pair of uni- 272 directional VC LSPs. When a new MAC address is learned on an inbound 273 VC LSP, it needs to be associated with the outbound VC LSP that is 274 part of the same pair. The state of this logical link can be 275 considered as up as soon as both incoming and outgoing LSPs are 276 established. Similarly, it can be considered as down as soon as one 277 of these two LSPs is torn down. 279 Standard learning, filtering and forwarding actions, as defined in 280 [802.1D-ORIG], [802.1D-REV] and [802.1Q], are required when a 281 logical link state changes. 283 5.3. LSP Topology 285 PE routers typically run an IGP between them, and are assumed to 286 have the capability to establish MPLS tunnels. Tunnel LSPs are set 287 up between PEs to aggregate traffic. Pseudowires are signaled to 288 demultiplex the L2 encapsulated packets that traverse the tunnel 289 LSPs. 291 In an Ethernet L2VPN, it becomes the responsibility of the service 292 provider to create the loop free topology. For the sake of 293 simplicity, we assume that the topology of a VPLS is a full mesh of 294 tunnel and pseudowires. 296 5.4. Loop free L2 VPN 298 For simplicity, a full mesh of pseudowires is established between 299 PEs. Ethernet bridges, unlike Frame Relay or ATM where the 300 termination point becomes the CE node, has to examine the layer 2 301 fields of the packets to make a switching decision. If the frame is 302 a destination unknown, broadcast or multicast frame the frame must 303 be flooded. 305 Therefore, if the topology isn't a full mesh, the PE devices may 306 need to forward these frames to other PEs. However, this would 307 require the use of spanning tree protocol to form a loop free 308 topology, that may have characteristics that are undesirable to the 309 provider. The use of a full mesh and split-horizon forwarding 310 obviates the need for a spanning tree protocol. 312 Each PE MUST create a rooted tree to every other PE router that 313 serve the same L2 VPN. Each PE MUST support a "split-horizon" scheme 314 in order to prevent loops, that is, a PE MUST NOT forward traffic 315 from one pseudowire to another in the same VPN (since each PE has 316 direct connectivity to all other PEs in the same VPN). 318 Note that customers are allowed to run STP such as when a customer 319 has "back door" links used to provide redundancy in the case of a 320 failure within the VPLS. In such a case, STP BPDUs are simply 321 tunneled through the MPLS cloud. 323 6. Discovery 325 Currently, no discovery mechanism has been prescribed for VPLS. 326 There are three potential candidates, [BGP-DISC], [DNS-DISC], [LDP- 327 DISC]. 329 7. Control Plane 331 This document describes the control plane functions of Demultiplexor 332 Exchange (signaling of VC labels). Some foundational work in the 333 area of support for multi-homing is laid, although that work is 334 described in a different document [VPLS-BRIDGING]. 336 7.1. LDP Based Signaling of Demultiplexors 338 In order to establish a full mesh of pseudowires, all PEs in a VPLS 339 must have a full mesh of LDP sessions. 341 Once an LDP session has been formed between two PEs, all pseudowires 342 are signaled over this session. 344 In [PWE3-CTRL], the L2 VPN information is carried in a Label Mapping 345 message sent in downstream unsolicited mode, which contains the 346 following VC FEC TLV. VC, C, VC Info Length, Group ID, Interface 347 parameters are as defined in [PWE3-CTRL]. 349 0 1 2 3 350 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 1 351 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 352 | VC tlv |C| VC Type |VC info Length | 353 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 354 | Group ID | 355 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 356 | VCID | 357 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 358 | Interface parameters | 359 ~ ~ 360 | | 361 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 363 This document uses the VC type value for Ethernet as defined in 364 [PWE3-CTRL]: 366 VC Type Description 368 0x0001 Frame Relay DLCI 369 0x0002 ATM AAL5 VCC transport 370 0x0003 ATM transparent cell transport 371 0x0004 Ethernet VLAN 372 0x0005 Ethernet 373 0x0006 HDLC 374 0x0007 PPP 375 0x8008 CEM [8] 376 0x0009 ATM VCC cell transport 377 0x000A ATM VPC cell transport 379 VC types 0x0004 and 0x0005 identify pseudowire types that carry VLAN 380 tagged and untagged Ethernet traffic respectively, for point-to- 381 point connectivity. 383 We use the VC type Ethernet with codepoint 0x0005 to identify 384 pseudowires that carry Ethernet traffic for multipoint connectivity. 385 The Ethernet VC Type described below, conforms to the Ethernet VC 386 Type defined in [PWE3-CTRL]. 388 In a VPLS, we use a VCID (to be substituted with a VPNID TLV later, 389 to address extending the scope of a VPLS) to identify an emulated 390 LAN segment. Note that the VCID as specified in [PWE3-CTRL] is a 391 service identifier, identifying a service emulating a point-to-point 392 virtual circuit. In a VPLS, the VCID is a single service 393 identifier. 395 7.2. MAC Address Withdrawal 397 It MAY be desirable to remove or relearn MAC addresses that have 398 been dynamically learned for faster convergence. 400 We introduce an optional MAC TLV that is used to specify a list of 401 MAC addresses that can be removed or relearned using the Address 402 Withdraw Message. 404 The Address Withdraw message with MAC TLVs MAY be supported in order 405 to expedite learning of MAC addresses as the result of a topology 406 change (e.g., failure of the primary link for a dual-homed MTU-s). 407 If a notification message is sent on the backup link (blocked link), 408 which has transitioned into an active state (e.g., similar to 409 Topology Change Notification message of 802.1w RSTP), with a list of 410 MAC entries to be relearned, the PE will update the MAC entries in 411 its FIB for that VPLS instance and send the message to other PEs 412 over the corresponding directed LDP sessions. 414 If the notification message contains an empty list, this tells the 415 receiving PE to remove all the MAC addresses learned for the 416 specified VPLS instance except the ones it learned from the sending 417 PE (MAC address removal is required for all VPLS instances that are 418 affected). Note that the definition of such a notification message 419 is outside the scope of the document, unless it happens to come from 420 an MTU connected to the PE as a spoke. In such a scenario, the 421 message will be just an Address Withdraw message as noted above. 423 7.2.1. MAC TLV 425 MAC addresses to be relearned can be signaled using an LDP Address 426 Withdraw Message that contains a new TLV, the MAC TLV. Its format 427 is described below. The encoding of a MAC TLV address is the 6-byte 428 MAC address specified by IEEE 802 documents [g-ORIG] [802.1D-REV]. 430 0 1 2 3 431 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 1 432 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 433 |U|F| Type | Length | 434 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 435 | MAC address #1 | 436 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 437 | MAC address #n | 438 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 440 U bit 441 Unknown bit. This bit MUST be set to 0. If the MAC address 442 format is not understood, then the TLV is not understood, and MUST 443 be ignored. 445 F bit 446 Forward bit. This bit MUST be set to 0. Since the LDP 447 mechanism used here is Targeted, the TLV MUST NOT be forwarded. 449 Type 450 Type field. This field MUST be set to 0x0404 (subject to IANA 451 approval). This identifies the TLV type as MAC TLV. 453 Length 454 Length field. This field specifies the total length of the 455 TLV, including the Type and Length fields. 457 MAC Address 458 The MAC address being removed. 460 The LDP Address Withdraw Message contains a FEC TLV (to identify the 461 VPLS in consideration), a MAC Address TLV and optional parameters. 462 No optional parameters have been defined for the MAC Address 463 Withdraw signaling. 465 7.2.2. Address Withdraw Message Containing MAC TLV 467 When MAC addresses are being removed or relearned explicitly, e.g., 468 the primary link of a dual-homed MTU-s has failed, an Address 469 Withdraw Message can be sent with the list of MAC addresses to be 470 relearned. 472 The processing for MAC TLVs received in an Address Withdraw Message 473 is: 474 For each MAC address in the TLV: 475 - Relearn the association between the MAC address and the 476 interface/pseudowire over which this message is received 477 - Send the same message to all other PEs over the corresponding 478 directed LDP sessions. 480 For an Address Withdraw message with empty list: 481 - Remove all the MAC addresses associated with the VPLS instance 482 (specified by the FEC TLV) except the MAC addresses learned 483 over this link (over the pseudowire associated with the 484 signaling link over which the message is received) 485 - Send the same message to all other PEs over the corresponding 486 directed LDP sessions. 488 The scope of a MAC TLV is the VPLS specified in the FEC TLV in the 489 Address Withdraw Message. The number of MAC addresses can be 490 deduced from the length field in the TLV. 492 Further descriptions of how to deal with failures expeditiously with 493 different configurations will be described in other documents, such 494 as [VPLS-BRIDGING]. 496 8. Data Forwarding on an Ethernet VC Type 498 This section describes the dataplane behavior on an Ethernet VPLS 499 pseudowire. While the encapsulation is similar to that described in 500 [PWE3-ETHERNET], the NSP functions of stripping the service- 501 delimiting tag, and using a "normalized" Ethernet packet are 502 described. 504 8.1. VPLS Encapsulation actions 506 In a VPLS, a customer Ethernet packet without preamble is 507 encapsulated with a header as defined in [PWE3-ETHERNET]. A 508 customer Ethernet packet is defined as follows: 510 - If the packet, as it arrives at the PE, has an encapsulation 511 that is used by the local PE as a service delimiter, then that 512 encapsulation is stripped before the packet is sent into the 513 VPLS. As the packet exits the VPLS, the packet may have a 514 service-delimiting encapsulation inserted. 516 - If the packet, as it arrives at the PE, has an encapsulation 517 that is not service delimiting, then it is a customer packet 518 whose encapsulation should not be modified by the VPLS. This 519 covers, for example, a packet that carries customer specific 520 VLAN-Ids that the service provider neither knows about nor 521 wants to modify. 523 By following the above rules, the Ethernet packet that traverses a 524 VPLS is always a customer Ethernet packet. Note that the two 525 actions, at ingress and egress, of dealing with service delimiters 526 are local actions that neither PE has to signal to the other. They 527 allow, for example, a mix-and-match of VLAN tagged and untagged 528 services at either end, and do not carry across a VPLS a VLAN tag 529 that may have only local significance. The service delimiter may be 530 an MPLS label also, whereby an Ethernet pseudowire given by [PWE3- 531 ETHERNET] can serve as the access side connection into a PE. An 532 RFC1483 PVC encapsulation could be another service delimiter. By 533 limiting the scope of locally significant encapsulations to the 534 edge, hierarchical VPLS models can be developed that provide the 535 capability to network-engineer VPLS deployments, as described below. 537 8.1.1. VPLS Learning actions 538 Learning is done based on the customer Ethernet packet, as defined 539 above. The Forwarding Information Base (FIB) keeps track of the 540 mapping of customer Ethernet packet addressing and the appropriate 541 pseudowire to use. We define two modes of learning: qualified and 542 unqualified learning. 544 In unqualified learning, all the customer VLANs are handled by a 545 single VPLS, which means they all share a single broadcast domain 546 and a single MAC address space. This means that MAC addresses need 547 to be unique and non-overlapping among customer VLANs or else they 548 cannot be differentiated within the VPLS instance and this can 549 result in loss of customer frames. An application of unqualified 550 learning is port-based VPLS service for a given customer (e.g., 551 customer with non-multiplexed UNI interface where all the traffic on 552 a physical port, which may include multiple customer VLANs, is 553 mapped to a single VPLS instance). 555 In qualified learning, each customer VLAN is assigned to its own 556 VPLS instance, which means each customer VLAN has its own broadcast 557 domain and MAC address space. Therefore, in qualified learning, MAC 558 addresses among customer VLANs may overlap with each other, but they 559 will be handled correctly since each customer VLAN has its own FIB , 560 i.e., each customer VLAN has its own MAC address space. Since VPLS 561 broadcasts multicast frames, qualified learning offers the advantage 562 of limiting the broadcast scope to a given customer VLAN. 564 9. Operation of a VPLS 566 We show here an example of how a VPLS works. The following 567 discussion uses the figure below, where a VPLS has been set up 568 between PE1, PE2 and PE3. 570 Initially, the VPLS is set up so that PE1, PE2 and PE3 have a full- 571 mesh of Ethernet pseudowires. The VPLS instance is assigned a 572 unique VCID. 574 For the above example, say PE1 signals VC Label 102 to PE2 and 103 575 to PE3, and PE2 signals VC Label 201 to PE1 and 203 to PE3. 577 Assume a packet from A1 is bound for A2. When it leaves CE1, say it 578 has a source MAC address of M1 and a destination MAC of M2. If PE1 579 does not know where M2 is, it will multicast the packet to PE2 and 580 PE3. When PE2 receives the packet, it will have an inner label of 581 201. PE2 can conclude that the source MAC address M1 is behind PE1, 582 since it distributed the label 201 to PE1. It can therefore 583 associate MAC address M1 with VC Label 102. 585 ----- 586 / A1 \ 587 ---- ----CE1 | 588 / \ -------- ------- / | | 589 | A2 CE2- / \ / PE1 \ / 590 \ / \ / \---/ \ ----- 591 ---- ---PE2 | 592 | Service Provider Network | 593 \ / \ / 594 ----- PE3 / \ / 595 |Agg|_/ -------- ------- 596 -| | 597 ---- / ----- ---- 598 / \/ \ / \ CE = Customer Edge Router 599 | A3 CE3 --C4 A4 | PE = Provider Edge Router 600 \ / \ / Agg = Layer 2 Aggregation 601 ---- ---- 603 9.1. MAC Address Aging 605 PEs that learn remote MAC addresses need to have an aging mechanism 606 to remove unused entries associated with a VC Label. This is 607 important both for conservation of memory as well as for 608 administrative purposes. For example, if a customer site A is shut 609 down, eventually, the other PEs should unlearn A's MAC address. 611 As packets arrive, MAC addresses are remembered. The aging timer 612 for MAC address M SHOULD be reset when a packet is received with 613 source MAC address M. 615 10. A Hierarchical VPLS Model 617 The solution described above requires a full mesh of tunnel LSPs 618 between all the PE routers that participate in the VPLS service. 619 For each VPLS service, n*(n-1)/2 pseudowires must be setup between 620 the PE routers. While this creates signaling overhead, the real 621 detriment to large scale deployment is the packet replication 622 requirements for each provisioned VCs on a PE router. Hierarchical 623 connectivity, described in this document reduces signaling and 624 replication overhead to allow large scale deployment. 626 In many cases, service providers place smaller edge devices in 627 multi-tenant buildings and aggregate them into a PE device in a 628 large Central Office (CO) facility. In some instances, standard IEEE 629 802.1q (Dot 1Q) tagging techniques may be used to facilitate mapping 630 CE interfaces to PE VPLS access points. 632 It is often beneficial to extend the VPLS service tunneling 633 techniques into the MTU domain. This can be accomplished by 634 treating the MTU device as a PE device and provisioning pseudowires 635 between it and every other edge, as an basic VPLS. An alternative 636 is to utilize [PWE3-ETHERNET] pseudowires or Q-in-Q logical 637 interfaces between the MTU and selected VPLS enabled PE routers. Q- 638 in-Q encapsulation is another form of L2 tunneling technique, which 639 can be used in conjunction with MPLS signaling as will be described 640 later. The following two sections focus on this alternative 641 approach. The [VPLS] mesh core pseudowires (Hub) are augmented with 642 access pseudowires (Spoke) to form a two tier hierarchical VPLS (H- 643 VPLS). 645 Spoke pseudowires may be implemented using any L2 tunneling 646 mechanism, expanding the scope of the first tier to include non- 647 bridging VPLS PE routers. The non-bridging PE router would extend a 648 Spoke pseudowire from a Layer-2 switch that connects to it, through 649 the service core network, to a bridging VPLS PE router supporting 650 Hub pseudowires. We also describe how VPLS-challenged nodes and 651 low-end CEs without MPLS capabilities may participate in a 652 hierarchical VPLS. 654 10.1. Hierarchical connectivity 656 This section describes the hub and spoke connectivity model and 657 describes the requirements of the bridging capable and non-bridging 658 MTU devices for supporting the spoke connections. 660 For rest of this discussion we will refer to a bridging capable MTU 661 device as MTU-s and a non-bridging capable PE device as PE-r. A 662 routing and bridging capable device will be referred to as PE-rs. 664 10.1.1. Spoke connectivity for bridging-capable devices 666 As shown in the figure below, consider the case where an MTU-s 667 device has a single connection to the PE-rs device placed in the CO. 668 The PE-rs devices are connected in a basic VPLS full mesh. For each 669 VPLS service, a single spoke pseudowire is set up between the MTU-s 670 and the PE-rs based on [PWE3-CTRL]. Unlike traditional pseudowires 671 that terminate on a physical (or a VLAN-tagged logical) port at each 672 end, the spoke pseudowire terminates on a virtual bridge instance on 673 the MTU-s and the PE-rs devices. 675 PE2-rs 676 ------ 677 / \ 678 | -- | 679 | / \ | 680 CE-1 | \B / | 681 \ \ -- / 682 \ /------ 683 \ MTU-s PE1-rs / | 684 \ ------ ------ / | 685 / \ / \ / | 686 | \ -- | VC-1 | -- |---/ | 687 | / \--|- - - - - - - - - - - |--/ \ | | 688 | \B / | | \B / | | 689 \ /-- / \ -- / ---\ | 690 /----- ------ \ | 691 / \ | 692 ---- \ ------ 693 |Agg | / \ 694 ---- | -- | 695 / \ | / \ | 696 CE-2 CE-3 | \B / | 697 \ -- / 698 MTU-s = Bridging capable MTU ------ 699 PE-rs = VPLS capable PE PE3-rs 701 -- 702 / \ 703 \B / = Virtual VPLS(Bridge)Instance 704 -- 705 Agg = Layer-2 Aggregation 707 The MTU-s device and the PE-rs device treat each spoke connection 708 like an access port of the VPLS service. On access ports, the 709 combination of the physical port and/or the VLAN tag is used to 710 associate the traffic to a VPLS instance while the pseudowire tag 711 (e.g., VC label) is used to associate the traffic from the virtual 712 spoke port with a VPLS instance, followed by a standard L2 lookup to 713 identify which customer port the frame needs to be sent to. 715 10.1.1.1. MTU-s Operation 717 MTU-s device is defined as a device that supports layer-2 switching 718 functionality and does all the normal bridging functions of learning 719 and replication on all its ports, including the virtual spoke port. 720 Packets to unknown destination are replicated to all ports in the 721 service including the virtual spoke port. Once the MAC address is 722 learned, traffic between CE1 and CE2 will be switched locally by the 723 MTU-s device saving the link capacity of the connection to the PE- 724 rs. Similarly traffic between CE1 or CE2 and any remote destination 725 is switched directly on to the spoke connection and sent to the PE- 726 rs over the point-to-point pseudowire. 728 Since the MTU-s is bridging capable, only a single pseudowire is 729 required per VPLS instance for any number of access connections in 730 the same VPLS service. This further reduces the signaling overhead 731 between the MTU-s and PE-rs. 733 If the MTU-s is directly connected to the PE-rs, other encapsulation 734 techniques such as Q-in-Q can be used for the spoke connection 735 pseudowire. However, to maintain a uniform end-to-end control plane 736 based on MPLS signaling, [PWE3-CTRL] can be used for distribution of 737 pseudowire tags (e.g., Q-in-Q tags or pseudowire labels) between 738 MTU-s and PE-rs. 740 10.1.1.2. PE-rs Operation 742 The PE-rs device is a device that supports all the bridging 743 functions for VPLS service and supports the routing and MPLS 744 encapsulation, i.e. it supports all the functions described in 745 [VPLS]. 747 The operation of PE-rs is independent of the type of device at the 748 other end of the spoke pseudowire. Thus, the spoke pseudowire from 749 the PE-r is treated as a virtual port and the PE-rs device will 750 switch traffic between the spoke pseudowire, hub pseudowires, and 751 access ports once it has learned the MAC addresses. 753 10.1.2. Advantages of spoke connectivity 755 Spoke connectivity offers several scaling and operational advantages 756 for creating large scale VPLS implementations, while retaining the 757 ability to offer all the functionality of the VPLS service. 759 - Eliminates the need for a full mesh of tunnels and full mesh of 760 pseudowires per service between all devices participating in the 761 VPLS service. 762 - Minimizes signaling overhead since fewer pseudowires are required 763 for the VPLS service. 764 - Segments VPLS nodal discovery. MTU-s needs to be aware of only 765 the PE-rs node although it is participating in the VPLS service 766 that spans multiple devices. On the other hand, every VPLS PE-rs 767 must be aware of every other VPLS PE-rs device and all of it�s 768 locally connected MTU-s and PE-r. 769 - Addition of other sites requires configuration of the new MTU-s 770 device but does not require any provisioning of the existing MTU-s 771 devices on that service. 772 - Hierarchical connections can be used to create VPLS service that 773 spans multiple service provider domains. This is explained in a 774 later section. 776 10.1.3. Spoke connectivity for non-bridging devices 778 In some cases, a bridging PE-rs device may not be deployed in a CO 779 or a multi-tenant building while a PE-r might already be deployed. 780 If there is a need to provide VPLS service from the CO where the PE- 781 rs device is not available, the service provider may prefer to use 782 the PE-r device in the interim. In this section, we explain how a 783 PE-r device that does not support any of the VPLS bridging 784 functionality can participate in the VPLS service. 786 As shown in this figure, the PE-r device creates a point-to-point 787 tunnel LSP to a PE-rs device. Then for every access port that needs 789 PE2-rs 790 ------ 791 / \ 792 | -- | 793 | / \ | 794 CE-1 | \B / | 795 \ \ -- / 796 \ /------ 797 \ PE-r PE1-rs / | 798 \ ------ ------ / | 799 / \ / \ / | 800 | \ | VC-1 | -- |---/ | 801 | ------|- - - - - - - - - - - |--/ \ | | 802 | -----|- - - - - - - - - - - |--\B / | | 803 \ / / \ -- / ---\ | 804 ------ ------ \ | 805 / \ | 806 ---- \------ 807 | Agg| / \ 808 ---- | -- | 809 / \ | / \ | 810 CE-2 CE-3 | \B / | 811 \ -- / 812 ------ 813 PE3-rs 815 to participate in a VPLS service, the PE-r device creates a point- 816 to-point [PWE3-ETHERNET] pseudowire that terminates on the physical 817 port at the PE-r and terminates on the virtual bridge instance of 818 the VPLS service at the PE-rs. 820 10.1.3.1. PE-r Operation 822 The PE-r device is defined as a device that supports routing but 823 does not support any bridging functions. However, it is capable of 824 setting up [PWE3-ETHERNET] pseudowires between itself and the PE-rs. 826 For every port that is supported in the VPLS service, a [PWE3- 827 ETHERNET] pseudowire is setup from the PE-r to the PE-rs. Once the 828 pseudowires are setup, there is no learning or replication function 829 required on part of the PE-r. All traffic received on any of the 830 access ports is transmitted on the pseudowire. Similarly all 831 traffic received on a pseudowire is transmitted to the access port 832 where the pseudowire terminates. Thus traffic from CE1 destined for 833 CE2 is switched at PE-rs and not at PE-r. 835 This approach adds more overhead than the bridging capable (MTU-s) 836 spoke approach since a pseudowire is required for every access port 837 that participates in the service versus a single pseudowire required 838 per service (regardless of access ports) when a MTU-s type device is 839 used. However, this approach offers the advantage of offering a 840 VPLS service in conjunction with a routed internet service without 841 requiring the addition of new MTU device. 843 10.2. Redundant Spoke Connections 845 An obvious weakness of the hub and spoke approach described thus far 846 is that the MTU device has a single connection to the PE-rs device. 847 In case of failure of the connection or the PE-rs device, the MTU 848 device suffers total loss of connectivity. 850 In this section we describe how the redundant connections can be 851 provided to avoid total loss of connectivity from the MTU device. 852 The mechanism described is identical for both, MTU-s and PE-r type 853 of devices 855 10.2.1. Dual-homed MTU device 857 To protect from connection failure of the pseudowire or the failure 858 of the PE-rs device, the MTU-s device or the PE-r is dual-homed into 859 two PE-rs devices, as shown in figure-3. The PE-rs devices must be 860 part of the same VPLS service instance. 862 An MTU-s device will setup two [PWE3-ETHERNET] pseudowires (one each 863 to PE-rs1 and PE-rs2) for each VPLS instance. One of the two 864 pseudowires is designated as primary and is the one that is actively 865 used under normal conditions, while the second pseudowire is 866 designated as secondary and is held in a standby state. The MTU 867 device negotiates the pseudowire labels for both the primary and 868 secondary pseudowires, but does not use the secondary pseudowire 869 unless the primary pseudowire fails. Since only one link is active 870 at a given time, a loop does not exist and hence 802.1D spanning 871 tree is not required. 873 PE2-rs 874 ------ 875 / \ 876 | -- | 877 | / \ | 878 CE-1 | \B / | 879 \ \ -- / 880 \ /------ 881 \ MTU-s PE1-rs / | 882 \------ ------ / | 883 / \ / \ / | 884 | -- | Primary PW | -- |---/ | 885 | / \--|- - - - - - - - - - - |--/ \ | | 886 | \B / | | \B / | | 887 \ -- \/ \ -- / ---\ | 888 ------\ ------ \ | 889 / \ \ | 890 / \ \ ------ 891 / \ / \ 892 CE-2 \ | -- | 893 \ Secondary PW | / \ | 894 - - - - - - - - - - - - - - - - - |-\B / | 895 \ -- / 896 ------ 897 PE3-rs 899 10.2.2. Failure detection and recovery 901 The MTU-s device controls the usage of the pseudowires to the PE-rs 902 nodes. Since LDP signaling is used to negotiate the pseudowire 903 labels, the hello messages used for the LDP session can be used to 904 detect failure of the primary pseudowire. 906 Upon failure of the primary pseudowire, MTU-s device immediately 907 switches to the secondary pseudowire. At this point the PE3-rs 908 device that terminates the secondary pseudowire starts learning MAC 909 addresses on the spoke pseudowire. All other PE-rs nodes in the 910 network think that CE-1 and CE-2 are behind PE1-rs and may continue 911 to send traffic to PE1-rs until they learn that the devices are now 912 behind PE3-rs. The relearning process can take a long time and may 913 adversely affect the connectivity of higher level protocols from CE1 914 and CE2. To enable faster convergence, the PE3-rs device where the 915 secondary pseudowire got activated may send out a flush message, 916 using the MAC TLV as defined in Section 6, to PE1-rs, who relays it 917 to all other PE-rs devices participating in the VPLS service. Upon 918 receiving the message, all PE-rs nodes flush the MAC addresses 919 associated with that VPLS instance. 921 10.3. Multi-domain VPLS service 923 Hierarchy can also be used to create a large scale VPLS service 924 within a single domain or a service that spans multiple domains 925 without requiring full mesh connectivity between all VPLS capable 926 devices. Two fully meshed VPLS networks are connected together 927 using a single LSP tunnel between the VPLS gateway devices. A 928 single spoke pseudowire is setup per VPLS service to connect the two 929 domains together. The VPLS gateway device joins two VPLS services 930 together to form a single multi-domain VPLS service. The 931 requirements and functionality required from a VPLS gateway device 932 will be explained in a future version of this document. 934 11. Hierarchical VPLS model using Ethernet Access Network 936 In the previous section, a two-tier hierarchical model that consists 937 of hub-and-spoke topology between MTU-s devices and PE-rs devices and 938 a full-mesh topology among PE-rs devices was discussed. In this 939 section the two-tier hierarchical model is expanded to include an 940 Ethernet access network. This model retains the hierarchical 941 architecture discussed previously in that it leverages the full-mesh 942 topology among PE-rs devices; however, no restriction is imposed on 943 the topology of the Ethernet access network (e.g., the topology 944 between MTU-s and PE-rs devices are not restricted to hub and spoke). 946 The motivation for an Ethernet access network is that Ethernet-based 947 networks are currently deployed by some service providers to offer 948 VPLS services to their customers. Therefore, it is important to 949 provide a mechanism that allows these networks to integrate with an 950 IP or MPLS core to provide scalable VPLS services. 952 One approach of tunneling a customer�s Ethernet traffic via an 953 Ethernet access network is to add an additional VLAN tag to the 954 customer�s data (either tagged or untagged). The additional tag is 955 referred to as Provider�s VLAN (P-VLAN). Inside the provider�s 956 network each P-VLAN designates a customer or more specifically a VPLS 957 instance for that customer. Therefore, there is a one to one 958 correspondence between a P-VLAN and a VPLS instance. 960 In this model, the MTU-S device needs to have the capability of 961 adding the additional P-VLAN tag for non-multiplexed customer UNI 962 port where customer VLANs are not used as service delimiter. If 963 customer VLANs need to be treated as service delimiter (e.g., 964 customer UNI port is a multiplexed port), then the MTU-s needs to 965 have the additional capability of translating a customer VLAN (C- 966 VLAN) to a P-VLAN in order to resolve overlapping VLAN-ids used by 967 different customers. Therefore, the MTU-s device in this model can be 968 considered as a typical bridge with this additional UNI capability. 970 The PE-rs device needs to be able to perform bridging functionality 971 over the standard Ethernet ports toward the access network as well as 972 over the pseudowires toward the network core. The set of pseudowires 973 that corresponds to a VPLS instance would look just like a P-VLAN to 974 the bridge portion of the PE-rs and that is why sometimes it is 975 referred to as Emulated VLAN. In this model the PE-rs may need to run 976 STP protocol in addition to split-horizon. Split horizon is run over 977 MPLS-core; whereas, STP is run over the access network to accommodate 978 any arbitrary access topology. In this model, the PE-rs needs to map 979 a P-VLAN to a VPLS-instance and its associated pseudowires and vise 980 versa. 982 The details regarding bridge operation for MTU-s and PE-rs (e.g., 983 encapsulation format for QinQ messages, customer�s Ethernet control 984 protocol handling, etc.) are outside of the scope of this document 985 and they are covered in [802.1ad]. However, the relevant part is the 986 interaction between the bridge module and the MPLS/IP pseudowires in 987 the PE-rs device. 989 11.1. Scalability 991 Given that each P-VLAN corresponds to a VPLS instance, one may think 992 that the total number of VPLS instances supported is limited to 4K. 993 However, 4K limit applies only to each Ethernet access network 994 (Ethernet island) and not to the entire network. The SP network, in 995 this model, consists of a core MPLS/IP network that connects many 996 Ethernet islands. Therefore, the number of VPLS instances can scale 997 accordingly with the number of Ethernet islands (a metro region can 998 be represented by one or more islands). Each island may consist of 999 many MTU-s devices, several aggregators, and one or more PE-rs 1000 devices. The PE-rs devices enable a P-VLAN to be extended from one 1001 island to others using a set of pseudowires (associated with that 1002 VPLS instance) and providing a loop free mechanism across the core 1003 network through split-horizon. Since a P-VLAN serves as a service 1004 delimiter within the providers network, it does not get carried over 1005 the pseudowires and furthermore the mapping between P-VLAN and the 1006 pseudowires is a local matter. This means a VPLS instance can be 1007 represented by different P-VLAN in different Ethernet islands and 1008 furthermore each island can support 4K VPLS instances independent 1009 from one another. 1011 11.2. Dual Homing and Failure Recovery 1013 In this model, an MTU-s can be dual or triple homed to different 1014 devices (aggregators and/or PE-rs devices). The failure protection 1015 for access network nodes and links can be provided through running 1016 MSTP in each island. The MSTP of each island is independent from 1017 other islands and do not interact with each other. If an island has 1018 more than one PE-rs, then a dedicated full-mesh of pseudowires is 1019 used among these PE-rs devices for carrying the SP BPDU packets for 1020 that island. On a per P-VLAN basis, the MSTP will designate a single 1021 PE-rs to be used for carrying the traffic across the core. The loop- 1022 free protection through the core is performed using split-horizon and 1023 the failure protection in the core is performed through standard 1024 IP/MPLS re-routing. 1026 12. Significant Modifications 1028 Between rev 03 and this one, these are the changes: 1029 o replace the VC Type for VPLS to the Ethernet VC Type 1030 o align with L2 framework terminology 1031 o clean up descriptions, typos 1032 o updated references 1034 13. Acknowledgments 1036 We wish to thank Joe Regan, Kireeti Kompella, Anoop Ghanwani, Joel 1037 Halpern, Rick Wilder,Jim Guichard, Steve Phillips, Norm Finn, Matt 1038 Squire, Muneyoshi Suzuki, Waldemar Augustyn, and Eric Rosen for 1039 their valuable feedback. 1041 14. Security Considerations 1043 Security issues resulting from this draft will be discussed in 1044 greater depth at a later point. It is recommended in [RFC3036] that 1045 LDP security (authentication) methods be applied. This would 1046 prevent unauthorized participation by a PE in a VPLS. Traffic 1047 separation for a VPLS is effected by using VC labels. However, for 1048 additional levels of security, the customer MAY deploy end-to-end 1049 security, which is out of the scope of this draft. In addition, the 1050 L2FRAME] document describes security issues in greater depth. 1052 15. Intellectual Property Considerations 1054 This document is being submitted for use in IETF standards 1055 discussions. 1057 16. Full Copyright Statement 1059 Copyright (C) The Internet Society (2001). All Rights Reserved. 1060 This document and translations of it may be copied and furnished to 1061 others, and derivative works that comment on or otherwise explain it 1062 or assist in its implementation may be prepared, copied, published 1063 and distributed, in whole or in part, without restriction of any 1064 kind, provided that the above copyright notice and this paragraph 1065 are included on all such copies and derivative works. However, this 1066 document itself may not be modified in any way, such as by removing 1067 the copyright notice or references to the Internet Society or other 1068 Internet organizations, except as needed for the purpose of 1069 developing Internet standards in which case the procedures for 1070 copyrights defined in the Internet Standards process must be 1071 followed, or as required to translate it into languages other than 1072 English. 1074 The limited permissions granted above are perpetual and will not be 1075 revoked by the Internet Society or its successors or assigns. 1077 This document and the information contained herein is provided on an 1078 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 1079 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 1080 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 1081 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 1082 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1084 17. References 1086 [PWE3-ETHERNET] "Encapsulation Methods for Transport of Ethernet 1087 Frames Over IP/MPLS Networks", draft-ietf-pwe3-ethernet-encap- 1088 01.txt, Work in progress, November 2002. 1090 [PWE3-CTRL] "Transport of Layer 2 Frames Over MPLS", draft-ietf- 1091 pwe3-control-protocol-01.txt, Work in progress, November 2002. 1093 [802.1D-ORIG] Original 802.1D - ISO/IEC 10038, ANSI/IEEE Std 802.1D- 1094 1993 "MAC Bridges". 1096 [802.1D-REV] 802.1D - "Information technology - Telecommunications 1097 and information exchange between systems - Local and metropolitan 1098 area networks - Common specifications - Part 3: Media Access Control 1099 (MAC) Bridges: Revision. This is a revision of ISO/IEC 10038: 1993, 1100 802.1j-1992 and 802.6k-1992. It incorporates P802.11c, P802.1p and 1101 P802.12e." ISO/IEC 15802-3: 1998. 1103 [802.1Q] 802.1Q - ANSI/IEEE Draft Standard P802.1Q/D11, "IEEE 1104 Standards for Local and Metropolitan Area Networks: Virtual Bridged 1105 Local Area Networks", July 1998. 1107 [BGP-VPN] Rosen and Rekhter, "BGP/MPLS VPNs". draft-ietf-ppvpn- 1108 rfc2547bis-03.txt, Work in Progress, October 2002. 1110 [RFC3036] "LDP Specification", L. Andersson, et al. RFC 3036. 1111 January 2001. 1113 [DNS-DISC] "Using DNS for VPN Discovery", J. Luciani et al, draft- 1114 luciani-ppvpn-vpn-discovery-03.txt, Work in Progress, October 2002. 1116 [BGP-DISC] "Using BGP as an Auto-Discovery Mechanism for Network- 1117 based VPNs", Ould-Brahim, et. al., draft-ietf-ppvpn-bgpvpn-auto- 1118 03.txt, Work in Progress, August 2002. 1120 [LDP-DISC] "Discovering Nodes and Services in a VPLS Network", O. 1121 Stokes et al, draft-stokes-ppvpn-vpls-discover-00.txt, Work in 1122 Progress, June 2002. 1124 [VPLS-BRIDGING] "Bridging and VPLS", draft-finn-ppvpn-bridging-vpls- 1125 00.txt, Work in Progress, June 2002. 1127 [L2VPN-SIG] "LDP-based Signaling for L2VPNs", draft-rosen-ppvpn-l2- 1128 signaling-02.txt, Work in Progress, September 2002. 1130 [L2FRAME] "L2VPN Framework", draft-ietf-ppvpn-l2-framework-03, Work 1131 in Progress, February 2003. 1133 [L2VPN-REQ] "Service Requirements for Layer 2 Provider Provisioned 1134 Virtual Private Networks", draft-augustyn-ppvpn-l2vpn-requirements- 1135 02.txt, Work in Progress, February 2003. 1137 [802.1ad] "IEEE standard for Provider Bridges", Work in Progress, 1138 December 2002. 1140 18. Authors' Addresses 1142 Marc Lasserre 1143 Riverstone Networks 1144 5200 Great America Pkwy 1145 Santa Clara, CA 95054 1146 Email: marc@riverstonenet.com 1148 Vach Kompella 1149 TiMetra Networks 1150 274 Ferguson Dr. 1151 Mountain View, CA 94043 1152 Email: vkompella@timetra.com 1154 Sunil Khandekar 1155 TiMetra Networks 1156 274 Ferguson Dr. 1157 Mountain View, CA 94043 1158 Email: sunil@timetra.com 1160 Nick Tingle 1161 TiMetra Networks 1162 274 Ferguson Dr. 1163 Mountain View, CA 94043 1164 Email: nick@timetra.com 1166 Ali Sajassi 1167 Cisco Systems, Inc. 1168 170 West Tasman Drive 1169 San Jose, CA 95134 1170 Email: sajassi@cisco.com 1171 Loa Andersson 1172 Email: loa@pi.se 1174 Pascal Menezes 1175 Email: pascalm1@yahoo.com 1176 Andrew Smith 1177 Consultant 1178 Email: ah_smith@pacbell.net 1180 Giles Heron 1181 PacketExchange Ltd. 1182 The Truman Brewery 1183 91 Brick Lane 1184 LONDON E1 6QL 1185 United Kingdom 1186 Email: giles@packetexchange.net 1188 Juha Heinanen 1189 Song Networks, Inc. 1190 Email: jh@lohi.eng.song.fi 1192 Tom S. C. Soon 1193 SBC Technology Resources Inc. 1194 4698 Willow Road 1195 Pleasanton, CA 94588 1196 Email: sxsoon@tri.sbc.com 1198 Yetik Serbest 1199 SBC Communications 1200 9505 Arboretum Blvd. 1201 Austin TX 78759 1202 serbest@tri.sbc.com 1204 Eric Puetz 1205 SBC Communications 1206 9505 Arboretum Blvd. 1207 Austin TX 78759 1208 puetz@tri.sbc.com 1210 Ron Haberman 1211 Masergy Inc. 1212 2901 Telestar Ct. 1213 Falls Church, VA 22042 1214 Email: ronh@masergy.com 1216 Luca Martini 1217 Level 3 Communications, LLC. 1218 1025 Eldorado Blvd. 1219 Broomfield, CO, 80021 1220 Email: luca@level3.net 1221 Rob Nath 1222 Riverstone Networks 1223 5200 Great America Pkwy 1224 Santa Clara, CA 95054 1225 Email: rnath@riverstonenet.com 1227 Vasile Radaoca 1228 Nortel Networks 1229 600 Technology Park 1230 Billerica MA 01821 1231 Email: vasile@nortelnetworks.com