idnits 2.17.1 draft-ietf-mpls-mldp-hsmp-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (Sep 20, 2012) is 4235 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'RFC4762' is defined on line 491, but no explicit reference was found in the text == Unused Reference: 'RFC6374' is defined on line 495, but no explicit reference was found in the text == Outdated reference: A later version (-05) exists of draft-ietf-l2vpn-vpms-frmwk-requirements-04 == Outdated reference: A later version (-07) exists of draft-ietf-tictoc-1588overmpls-02 Summary: 0 errors (**), 0 flaws (~~), 5 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group L. Jin 3 Internet-Draft ZTE Corporation 4 Intended status: Standards Track F. Jounay 5 Expires: March 24, 2013 France Telecom 6 I. Wijnands 7 Cisco Systems, Inc 8 N. Leymann 9 Deutsche Telekom AG 10 Sep 20, 2012 12 LDP Extensions for Hub & Spoke Multipoint Label Switched Path 13 draft-ietf-mpls-mldp-hsmp-00.txt 15 Abstract 17 This draft introduces a hub & spoke multipoint LSP (short for HSMP 18 LSP), which allows traffic both from root to leaf through P2MP LSP 19 and also leaf to root along the co-routed reverse path. That means 20 traffic entering the HSMP LSP from application/customer at the root 21 node travels downstream, exactly as if it was traveling downstream 22 along a P2MP LSP to each leaf node, and traffic entering the HSMP LSP 23 at any leaf node travels upstream along the tree to the root as if it 24 is unicast to the root, except that it follows the path of the tree 25 rather than ordinary unicast to the root. 27 Requirements Language 29 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 30 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 31 document are to be interpreted as described in RFC2119 [RFC2119]. 33 Status of this Memo 35 This Internet-Draft is submitted in full conformance with the 36 provisions of BCP 78 and BCP 79. 38 Internet-Drafts are working documents of the Internet Engineering 39 Task Force (IETF). Note that other groups may also distribute 40 working documents as Internet-Drafts. The list of current Internet- 41 Drafts is at http://datatracker.ietf.org/drafts/current/. 43 Internet-Drafts are draft documents valid for a maximum of six months 44 and may be updated, replaced, or obsoleted by other documents at any 45 time. It is inappropriate to use Internet-Drafts as reference 46 material or to cite them other than as "work in progress." 48 This Internet-Draft will expire on March 24, 2013. 50 Copyright Notice 52 Copyright (c) 2012 IETF Trust and the persons identified as the 53 document authors. All rights reserved. 55 This document is subject to BCP 78 and the IETF Trust's Legal 56 Provisions Relating to IETF Documents 57 (http://trustee.ietf.org/license-info) in effect on the date of 58 publication of this document. Please review these documents 59 carefully, as they describe your rights and restrictions with respect 60 to this document. Code Components extracted from this document must 61 include Simplified BSD License text as described in Section 4.e of 62 the Trust Legal Provisions and are provided without warranty as 63 described in the Simplified BSD License. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 68 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 69 3. Applications . . . . . . . . . . . . . . . . . . . . . . . . . 3 70 3.1. Time synchronization scenario . . . . . . . . . . . . . . 4 71 3.2. VPMS scenario . . . . . . . . . . . . . . . . . . . . . . 4 72 3.3. IPTV scenario . . . . . . . . . . . . . . . . . . . . . . 4 73 4. Setting up HSMP LSP with LDP . . . . . . . . . . . . . . . . . 5 74 4.1. Support for HSMP LSP setup with LDP . . . . . . . . . . . 5 75 4.2. HSMP FEC Elements . . . . . . . . . . . . . . . . . . . . 6 76 4.3. Using the HSMP FEC Elements . . . . . . . . . . . . . . . 6 77 4.3.1. HSMP LSP Label Map . . . . . . . . . . . . . . . . . . 6 78 4.3.2. HSMP LSP Label Withdraw . . . . . . . . . . . . . . . 8 79 4.3.3. HSMP LSP upstream LSR change . . . . . . . . . . . . . 9 80 5. HSMP LSP on a LAN . . . . . . . . . . . . . . . . . . . . . . 9 81 6. Redundancy considerations . . . . . . . . . . . . . . . . . . 9 82 7. Co-routed path exceptions . . . . . . . . . . . . . . . . . . 9 83 8. Security Considerations . . . . . . . . . . . . . . . . . . . 10 84 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 85 10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 10 86 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 87 11.1. Normative references . . . . . . . . . . . . . . . . . . . 10 88 11.2. Informative References . . . . . . . . . . . . . . . . . . 11 89 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 91 1. Introduction 93 The point-to-multipoint LSP defined in [RFC6388] allows traffic to 94 transmit from root to several leaf nodes, and multipoint-to- 95 multipoint LSP allows traffic from every node to transmit to every 96 other node. This draft introduces a hub & spoke multipoint LSP 97 (short for HSMP LSP), which allows traffic both from root to leaf 98 through P2MP LSP and also leaf to root along the co-routed reverse 99 path. That means traffic entering the HSMP LSP at the root node 100 travels downstream, exactly as if it was traveling downstream along a 101 P2MP LSP, and traffic entering the HSMP LSP at any other node travels 102 upstream along the tree to the root. A packet traveling upstream 103 should be thought of as being unicast to the root, except that it 104 follows the path of the tree rather than ordinary unicast to the 105 root. 107 2. Terminology 109 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 110 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 111 document are to be interpreted as described in [RFC2119]. 113 This document uses some terms and acronyms as follows: 115 mLDP: Multipoint extensions for LDP 117 P2MP LSP: An LSP that has one Ingress LSR and one or more Egress 118 LSRs. 120 MP2MP LSP: An LSP that connects a set of nodes, such that traffic 121 sent by any node in the LSP is delivered to all others. 123 HSMP LSP: hub & spoke multipoint LSP. An LSP allows traffic both 124 from root to leaf through P2MP LSP and also leaf to root along the 125 co-routed reverse path. 127 PTP: The timing and synchronization protocol used by IEEE1588 129 3. Applications 131 In some cases, the P2MP LSP may not have a reply path for the OAM 132 message (e.g, LSP Ping). If P2MP LSP is provided by HSMP LSP, then 133 the upstream path could be exactly used as the OAM message reply 134 path. This is especially useful in the case of P2MP LSP fault 135 detection, performance measurement, root node redundancy and etc. 136 There are several other applications that could take advantage of 137 such kind of LDP based HSMP LSP as described below. 139 3.1. Time synchronization scenario 141 [IEEE1588] over MPLS is defined in [I-D.ietf-tictoc-1588overmpls]. 142 It is required that the LSP used to transport PTP event message 143 between a Master Clock and a Slave Clock, and the LSP between the 144 same Slave Clock and Master Clock must be co-routed. By using point- 145 to-multipoint technology to transmit PTP event messages from Master 146 Clock at root side to Slave Clock at leaf side will greatly improve 147 the bandwidth usage. Unfortunately current point-to-multipoint LSP 148 only provides unidirectional path from root to leaf, which cannot 149 provide a co-routed reverse path for the PTP event messages. LDP 150 based HSMP LSP described in this draft provides unidirectional point- 151 to-multipoint LSP from root to leaf and co-routed reverse path from 152 leaf to root. 154 3.2. VPMS scenario 156 Point to multipoint PW described in [I-D.ietf-pwe3-p2mp-pw] requires 157 to setup reverse path from leaf node (referred as egress PE) to root 158 node (referred as ingress PE), if HSMP LSP is used to multiplex P2MP 159 PW, the reverse path can also be multiplexed to HSMP upstream path to 160 avoid setup independent reverse path. In that case, the operational 161 cost will be reduced for maintaining only one HSMP LSP, instead of 162 P2MP LSP and n (number of leaf nodes) P2P reverse LSPs. 164 The VPMS defined in [I-D.ietf-l2vpn-vpms-frmwk-requirements] requires 165 reverse path from leaf to root node. The P2MP PW multiplexed to HSMP 166 LSP can provide VPMS with reverse path, without introducing 167 independent reverse path from each leaf to root. 169 3.3. IPTV scenario 171 The mLDP based HSMP LSP can also be applied in a typical IPTV 172 scenario. There is usually only one location with senders but there 173 are many receiver locations. If IGMP is used for signaling between 174 senders as IGMP querier and receivers, the IGMP messages from the 175 receivers are travelling only from the leaves to the root (and from 176 root towards leaves) but not from leaf to leaf. In addition traffic 177 from the root is only replicated towards the leaves. Then leaf node 178 receiving IGMP message (for SSM case) will join HSMP LSP, and then 179 send IGMP message upstream to root along HSMP LSP. Note that in 180 above case, there is no node redundancy for IGMP querier. And the 181 node redundancy for IGMP querier could be provided by two independent 182 VPMS instances with HSMP applied. 184 4. Setting up HSMP LSP with LDP 186 HSMP LSP is similar with MP2MP LSP described in [RFC6388], with the 187 difference that the leaf LSRs can only send traffic to root node 188 along the same path of traffic from root node to leaf node. 190 HSMP LSP consists of a downstream path and upstream path. The 191 downstream path is same as MP2MP LSP, while the upstream path is only 192 from leaf to root node, without communication between leaf and leaf 193 nodes. The transmission of packets from the root node of a HSMP LSP 194 to the receivers is identical to that of a P2MP LSP. Traffic from a 195 leaf node follows the upstream path toward the root node, along the 196 identical path of downstream path. 198 For setting up the upstream path of a HSMP LSP, ordered mode MUST be 199 used which is same as MP2MP. Ordered mode can guarantee a leaf to 200 start sending packets to root immediately after the upstream path is 201 installed, without being dropped due to an incomplete LSP. 203 Due to much of same behavior between HSMP LSP and MP2MP LSP, the 204 following sections only describe the difference between the two 205 entities. 207 4.1. Support for HSMP LSP setup with LDP 209 HSMP LSP also needs the LDP capabilities [RFC5561] to indicate the 210 supporting for the setup of HSMP LSPs. An implementation supporting 211 the HSMP LSP procedures specified in this document MUST implement the 212 procedures for Capability Parameters in Initialization Messages. 213 Advertisement of the HSMP LSP Capability indicates support of the 214 procedures for HSMP LSP setup. 216 A new Capability Parameter TLV is defined, the HSMP LSP Capability. 217 Following is the format of the HSMP LSP Capability Parameter. 219 0 1 2 3 220 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 1 221 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 222 |1|0| HSMP LSP Cap(TBD IANA) | Length (= 1) | 223 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 224 |1| Reserved | 225 +-+-+-+-+-+-+-+-+ 226 Figure 1. HSMP LSP Capability Parameter encoding 228 The HSMP LSP capability type is to be assigned by IANA. 230 4.2. HSMP FEC Elements 232 Similar as MP2MP LSP, we define two new protocol entities, the HSMP 233 downstream FEC and upstream FEC Element. If a FEC TLV contains an 234 HSMP FEC Element, the HSMP FEC Element MUST be the only FEC Element 235 in the FEC TLV. The structure, encoding and error handling for the 236 HSMP downstream and upstream FEC Elements are the same as for the 237 MP2MP FEC Element described in [RFC6388] Section 4.2. The difference 238 is that two additional new FEC types are used: HSMP downstream type 239 (TBD, IANA) and HSMP upstream type (TBD, IANA). 241 4.3. Using the HSMP FEC Elements 243 In order to describe the message processing clearly, following 244 defines the processing of the HSMP FEC Elements, which is inherited 245 from [RFC6388] section 4.3. 247 1. HSMP downstream LSP (or simply downstream ): a HSMP 248 LSP downstream path with root node address X and opaque value Y. 250 2. HSMP upstream LSP (or simply upstream ): a HSMP LSP 251 upstream path for root node address X and opaque value Y which will 252 be used by any of downstream node to send traffic upstream to root 253 node. 255 3. HSMP downstream FEC Element : a FEC Element with root node 256 address X and opaque value Y used for a downstream HSMP LSP. 258 4. HSMP upstream FEC Element : a FEC Element with root node 259 address X and opaque value Y used for an upstream HSMP LSP. 261 5. HSMP-D Label Map : A Label Map message with a single 262 HSMP downstream FEC Element and label TLV with label L. Label 263 L MUST be allocated from the per-platform label space of the LSR 264 sending the Label Map Message. 266 6. HSMP-U Label Map : A Label Map message with a single 267 HSMP upstream FEC Element and label TLV with label Lu. Label 268 Lu MUST be allocated from the per-platform label space of the LSR 269 sending the Label Map Message. 271 4.3.1. HSMP LSP Label Map 273 This section specifies the procedures for originating HSMP Label Map 274 messages and processing received HSMP label map messages for a 275 particular HSMP LSP. The procedure of downstream HSMP LSP is same as 276 that of downstream MP2MP LSP described in [RFC6388]. Under the 277 operation of ordered mode, the upstream LSP will be setup by sending 278 HSMP LSP mapping message with label which is allocated by upstream 279 LSR to its downstream LSR one by one from root to leaf node, 280 installing the upstream forwarding table by every node along the LSP. 281 Detail procedure of upstream HSMP LSP is different with that of 282 upstream MP2MP LSP, and is specified in below section. 284 All labels discussed here are downstream-assigned [RFC5332] except 285 those which are assigned using the procedures described in section 5. 287 Determining the upstream LSR for a HSMP LSP follows the 288 procedure for a MP2MP LSP described in [RFC6388] Section 4.3.1.1. 290 Determining one's downstream HSMP LSR procedure is much same as 291 defined in [RFC6388] section 4.3.1.2. A LDP peer U which receives a 292 HSMP-D Label Map from a LDP peer D will treat D as downstream HSMP 293 LSR. 295 Determining the forwarding interface to an LSR has same procedure as 296 defined in [RFC6388] section 2.4.1.2. 298 4.3.1.1. HSMP LSP leaf node operation 300 The leaf node operation is same as the operation of MP2MP LSP defined 301 in [RFC6388] section 4.3.1.4, only with different FEC element 302 processing and specified below. 304 A leaf node Z will send a HSMP-D Label Map to U, instead of 305 MP2MP-D Label Map . and expects a HSMP-U Label Map from node U and checks whether it already has forwarding state 307 for upstream . The created forwarding state on leaf node Z is 308 same as the leaf node of MP2MP LSP. Z will push label Lu onto the 309 traffic that Z wants to forward over the HSMP LSP. 311 4.3.1.2. HSMP LSP transit node operation 313 Suppose node Z receives a HSMP-D Label Map from LSR D, the 314 procedure is same as processing MP2MP-D Label Mapping message defined 315 in [RFC6388] section 4.3.1.5, and the processing protocol entity is 316 HSMP-D label mapping message. The different procedure is specified 317 below. 319 Node Z checks if upstream LSR U already assigned a label Lu to 320 upstream . If not, transit node Z waits until it receives a 321 HSMP-U Label Map from LSR U. Once the HSMP-U Label Map is 322 received from LSR U, node Z checks whether it already has forwarding 323 state upstream with incoming label Lu' and outgoing label Lu. 324 If it does, Z sends a HSMP-U Label Map to downstream 325 node. If it does not, it allocates a label Lu' and creates a new 326 label swap for Lu' with Label Lu over interface Iu. Interface Iu is 327 determined via the procedures in Section 4.3.1. Node Z determines 328 the downstream HSMP LSR as per Section 4.3.1, and sends a HSMP-U 329 Label Map to node D. 331 Since a packet from any downstream node is forwarded only to the 332 upstream node, the same label (representing the upstream path) can be 333 distributed to all downstream nodes. This differs from the 334 procedures for MPMP LSPs [RFC6388], where a distinct label must be 335 distributed to each downstream node. The forwarding state upstream 336 on node Z will be like this {, }. Iu means the 337 upstream interface over which Z receives HSMP-U Label Map 338 from LSR U. Packets from any downstream interface over which Z send 339 HSMP-U Label Map with label Lu' will be forwarded to Iu 340 with label Lu' swap to Lu. 342 4.3.1.3. HSMP LSP root node operation 344 Suppose root node Z receives a HSMP-D Label Map from node 345 D, the procedure is much same as processing MP2MP-D Label Mapping 346 message defined in [RFC6388] section 4.3.1.6, and the processing 347 protocol entity is HSMP-D label mapping message. The different 348 procedure is specified below. 350 Node Z checks if it has forwarding state for upstream . If 351 not, Z creates a forwarding state for incoming label Lu' that 352 indicates that Z is the LSP egress. E.g., the forwarding state might 353 specify that the label stack is popped and the packet passed to some 354 specific application. Node Z determines the downstream HSMP LSR as 355 per section 4.3.1, and sends a HSMP-U Label Map to node 356 D. 358 Since Z is the root of the tree, Z will not send a HSMP-D Label Map 359 and will not receive a HSMP-U Label Map. 361 4.3.2. HSMP LSP Label Withdraw 363 The HSMP Label Withdraw procedure is much same as MP2MP leaf 364 operation defined in [RFC6388] section 4.3.2, and the processing 365 protocol entities are HSMP FECs. The only difference is process of 366 HSMP-U label release message, which is specified below. 368 When a transit node Z receives a HSMP-U label release message from 369 downstream node D, Z should check if there are any incoming interface 370 in forwarding state upstream . If all downstream nodes are 371 released and there is no incoming interface, Z should delete the 372 forwarding state upstream and send HSMP-U label release 373 message to its upstream node. 375 4.3.3. HSMP LSP upstream LSR change 377 The procedure for changing the upstream LSR is the same as defined in 378 [RFC6388] section 4.3.3, except it is applied to HSMP FECs. 380 5. HSMP LSP on a LAN 382 The procedure to process P2MP LSP on a LAN has been described in 383 [RFC6388]. When the LSR forwards a packet downstream on one of those 384 LSPs, the packet's top label must be the "upstream LSR label", and 385 the packet's second label is "LSP label". 387 When establishing the downstream path of a HSMP LSP, as defined in 388 [RFC6389], a label request for a LSP label is send to the upstream 389 LSR. The upstream LSR should send label mapping that contains the 390 LSP label for the downstream HSMP FEC and the upstream LSR context 391 label. At the same time, it must also send label mapping for 392 upstream HSMP FEC to downstream node. Packets sent by the upstream 393 router can be forwarded downstream using this forwarding state based 394 on a two label lookup. Packets traveling upstream need to be 395 forwarded in the direction of the root by using the label allocated 396 by upstream LSR. 398 6. Redundancy considerations 400 In some scenario, it is necessary to provide two root nodes for 401 redundancy purpose. One way to implement this is to use two 402 independent HSMP LSPs acting as active/standby. At one time, only 403 one HSMP LSP will be active, and the other will be standby. After 404 detecting the failure of active HSMP LSP, the root and leaf nodes 405 will switch the traffic to the new active HSMP LSP which is switched 406 from former standby LSP. The detail of redundancy mechanism will be 407 for future study. 409 7. Co-routed path exceptions 411 There are some exceptional cases that mLDP based HSMP LSP could not 412 achieve co-routed path. One possible case is using static routing 413 between LDP neighbors; another possible case is IGP cost asymmetric 414 generated by physical link cost asymmetric, or TE-Tunnels used 415 between LDP neighbors. The LSR/LER in HSMP LSP could detect if the 416 path is co-routed or not, if not co-routed, an indication could be 417 generated to the management system. 419 8. Security Considerations 421 The same security considerations apply as for the MP2MP LSP described 422 in [RFC6388]. 424 9. IANA Considerations 426 This document requires allocation of two new LDP FEC Element types 427 from the "Label Distribution Protocol (LDP) Parameters registry" the 428 "Forwarding Equivalence Class (FEC) Type Name Space": 430 1. the HSMP-upstream FEC type - requested value TBD 432 2. the HSMP-downstream FEC type - requested value TBD 434 This document requires allocation of one new code points for the HSMP 435 LSP capability TLV from "Label Distribution Protocol (LDP) Parameters 436 registry" the "TLV Type Name Space": 438 HSMP LSP Capability Parameter - requested value TBD 440 10. Acknowledgement 442 The author would like to thank Eric Rosen, Sebastien Jobert, Fei Su, 443 Edward, Mach Chen, Thomas Morin for their valuable comments. 445 11. References 447 11.1. Normative references 449 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 450 Requirement Levels", BCP 14, RFC 2119, March 1997. 452 [RFC5332] Eckert, T., Rosen, E., Aggarwal, R., and Y. Rekhter, "MPLS 453 Multicast Encapsulations", RFC 5332, August 2008. 455 [RFC5561] Thomas, B., Raza, K., Aggarwal, S., Aggarwal, R., and JL. 456 Le Roux, "LDP Capabilities", RFC 5561, July 2009. 458 [RFC6388] Wijnands, IJ., Minei, I., Kompella, K., and B. Thomas, 459 "Label Distribution Protocol Extensions for Point-to- 460 Multipoint and Multipoint-to-Multipoint Label Switched 461 Paths", RFC 6388, November 2011. 463 [RFC6389] Aggarwal, R. and JL. Le Roux, "MPLS Upstream Label 464 Assignment for LDP", RFC 6389, November 2011. 466 11.2. Informative References 468 [I-D.ietf-l2vpn-vpms-frmwk-requirements] 469 Kamite, Y., JOUNAY, F., Niven-Jenkins, B., Brungard, D., 470 and L. Jin, "Framework and Requirements for Virtual 471 Private Multicast Service (VPMS)", 472 draft-ietf-l2vpn-vpms-frmwk-requirements-04 (work in 473 progress), July 2011. 475 [I-D.ietf-pwe3-p2mp-pw] 476 Sivabalan, S., Boutros, S., and L. Martini, "Signaling 477 Root-Initiated Point-to-Multipoint Pseudowire using LDP", 478 draft-ietf-pwe3-p2mp-pw-04 (work in progress), March 2012. 480 [I-D.ietf-tictoc-1588overmpls] 481 Davari, S., Oren, A., Bhatia, M., Roberts, P., and L. 482 Montini, "Transporting PTP messages (1588) over MPLS 483 Networks", draft-ietf-tictoc-1588overmpls-02 (work in 484 progress), October 2011. 486 [IEEE1588] 487 "IEEE standard for a precision clock synchronization 488 protocol for networked measurement and control systems", 489 IEEE1588v2 , March 2008. 491 [RFC4762] Lasserre, M. and V. Kompella, "Virtual Private LAN Service 492 (VPLS) Using Label Distribution Protocol (LDP) Signaling", 493 RFC 4762, January 2007. 495 [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay 496 Measurement for MPLS Networks", RFC 6374, September 2011. 498 Authors' Addresses 500 Lizhong Jin 501 ZTE Corporation 502 889, Bibo Road 503 Shanghai, 201203, China 505 Email: lizhong.jin@zte.com.cn 506 Frederic Jounay 507 France Telecom 508 2, avenue Pierre-Marzin 509 22307 Lannion Cedex, FRANCE 511 Email: frederic.jounay@orange.ch 513 IJsbrand Wijnands 514 Cisco Systems, Inc 515 De kleetlaan 6a 516 Diegem 1831, Belgium 518 Email: ice@cisco.com 520 Nicolai Leymann 521 Deutsche Telekom AG 522 Winterfeldtstrasse 21 523 Berlin 10781 525 Email: N.Leymann@telekom.de