idnits 2.17.1 draft-rabadan-bess-evpn-optimized-ir-01.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 : ---------------------------------------------------------------------------- ** The document seems to lack an Introduction section. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: o AR-LEAF nodes SHALL send service-level BM control plane packets following regular IR procedures. An example would be IGMP, MLD or PIM multicast packets. The AR-REPLICATORs MUST not replicate these control plane packets to other overlay tunnels since they will use the regular IR-IP Address. -- The document date (July 6, 2015) is 3210 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) == Missing Reference: 'EVPN' is mentioned on line 984, but not defined == Missing Reference: 'RFC6514' is mentioned on line 252, but not defined == Missing Reference: 'RFC2119' is mentioned on line 936, but not defined == Outdated reference: A later version (-12) exists of draft-ietf-bess-evpn-overlay-01 == Outdated reference: A later version (-03) exists of draft-ietf-bess-pta-flags-00 Summary: 1 error (**), 0 flaws (~~), 7 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 BESS Workgroup J. Rabadan, Ed. 3 Internet Draft S. Sathappan 4 Intended status: Standards Track W. Henderickx 5 Alcatel-Lucent 6 R. Shekhar 7 N. Sheth A. Sajassi 8 W. Lin Cisco 9 M. Katiyar 10 Juniper A. Isaac 11 Bloomberg 12 M. Tufail 13 Citibank 15 Expires: January 7, 2016 July 6, 2015 17 Optimized Ingress Replication solution for EVPN 18 draft-rabadan-bess-evpn-optimized-ir-01 20 Abstract 22 Network Virtualization Overlay (NVO) networks using EVPN as control 23 plane may use ingress replication (IR) or PIM-based trees to convey 24 the overlay multicast traffic. PIM provides an efficient solution to 25 avoid sending multiple copies of the same packet over the same 26 physical link, however it may not always be deployed in the NVO core 27 network. IR avoids the dependency on PIM in the NVO network core. 28 While IR provides a simple multicast transport, some NVO networks 29 with demanding multicast applications require a more efficient 30 solution without PIM in the core. This document describes a solution 31 to optimize the efficiency of IR in NVO networks. 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), its areas, and its working groups. Note that 40 other groups may also distribute working documents as Internet- 41 Drafts. 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 The list of current Internet-Drafts can be accessed at 49 http://www.ietf.org/ietf/1id-abstracts.txt 51 The list of Internet-Draft Shadow Directories can be accessed at 52 http://www.ietf.org/shadow.html 54 This Internet-Draft will expire on January 7, 2015. 56 Copyright Notice 58 Copyright (c) 2015 IETF Trust and the persons identified as the 59 document authors. All rights reserved. 61 This document is subject to BCP 78 and the IETF Trust's Legal 62 Provisions Relating to IETF Documents 63 (http://trustee.ietf.org/license-info) in effect on the date of 64 publication of this document. Please review these documents 65 carefully, as they describe your rights and restrictions with respect 66 to this document. Code Components extracted from this document must 67 include Simplified BSD License text as described in Section 4.e of 68 the Trust Legal Provisions and are provided without warranty as 69 described in the Simplified BSD License. 71 Table of Contents 73 1. Problem Statement . . . . . . . . . . . . . . . . . . . . . . . 3 74 2. Solution requirements . . . . . . . . . . . . . . . . . . . . . 4 75 3. EVPN BGP Attributes for optimized-IR . . . . . . . . . . . . . 5 76 4. Non-selective Assisted-Replication (AR) Solution Description . 7 77 4.1. Non-selective AR-REPLICATOR procedures . . . . . . . . . . 8 78 4.2. Non-selective AR-LEAF procedures . . . . . . . . . . . . . 9 79 4.3. RNVE procedures . . . . . . . . . . . . . . . . . . . . . . 10 80 4.4. Forwarding behavior in non-selective AR EVIs . . . . . . . 10 81 4.4.1. Broadcast and Multicast forwarding behavior . . . . . . 11 82 4.4.1.1. Non-selective AR-REPLICATOR BM forwarding . . . . . 11 83 4.4.1.2. Non-selective AR-LEAF BM forwarding . . . . . . . . 11 84 4.4.1.3. RNVE BM forwarding . . . . . . . . . . . . . . . . 12 85 4.4.2. Unknown unicast forwarding behavior . . . . . . . . . . 12 86 4.4.2.1. Non-selective AR-REPLICATOR/LEAF Unknown unicast 87 forwarding . . . . . . . . . . . . . . . . . . . . 12 88 4.4.2.2. RNVE Unknown unicast forwarding . . . . . . . . . . 13 89 5. Selective Assisted-Replication (AR) Solution Description . . . 13 90 5.1. Selective AR-REPLICATOR procedures . . . . . . . . . . . . 13 91 5.2. Selective AR-LEAF procedures . . . . . . . . . . . . . . . 15 92 5.3. Forwarding behavior in selective AR EVIs . . . . . . . . . 16 93 5.3.1. Selective AR-REPLICATOR BM forwarding . . . . . . . . . 16 94 5.3.2. Selective AR-LEAF BM forwarding . . . . . . . . . . . . 17 95 6. Pruned-Flood-Lists (PFL) . . . . . . . . . . . . . . . . . . . 17 96 6.1. A PFL example . . . . . . . . . . . . . . . . . . . . . . . 18 97 7. AR Procedures for single-IP AR-REPLICATORS . . . . . . . . . . 19 98 8. AR Procedures and EVPN Multi-homing Split-Horizon . . . . . . . 19 99 9. Out-of-band distribution of Broadcast/Multicast traffic . . . . 20 100 10. Benefits of the optimized-IR solution . . . . . . . . . . . . 20 101 11. Conventions used in this document . . . . . . . . . . . . . . 20 102 12. Security Considerations . . . . . . . . . . . . . . . . . . . 21 103 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 104 14. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 21 105 15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22 106 15.1 Normative References . . . . . . . . . . . . . . . . . . . 22 107 15.2 Informative References . . . . . . . . . . . . . . . . . . 22 108 16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 109 17. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 22 111 1. Problem Statement 113 EVPN may be used as the control plane for a Network Virtualization 114 Overlay (NVO) network. Network Virtualization Edge (NVE) devices and 115 PEs that are part of the same EVI use Ingress Replication (IR) or 116 PIM-based trees to transport the tenant's multicast traffic. In NVO 117 networks where PIM-based trees cannot be used, IR is the only 118 alternative. Examples of these situations are NVO networks where the 119 core nodes don't support PIM or the network operator does not want to 120 run PIM in the core. 122 In some use-cases, the amount of replication for BUM (Broadcast, 123 Unknown unicast and Multicast traffic) is kept under control on the 124 NVEs due to the following fairly common assumptions: 126 a) Broadcast is greatly reduced due to the proxy-ARP and proxy-ND 127 capabilities supported by EVPN on the NVEs. Some NVEs can even 128 provide DHCP-server functions for the attached Tenant Systems (TS) 129 reducing the broadcast even further. 131 b) Unknown unicast traffic is greatly reduced in virtualized NVO 132 networks where all the MAC and IP addresses are learnt in the 133 control plane. 135 c) Multicast applications are not used. 137 If the above assumptions are true for a given NVO network, then IR 138 provides a simple solution for multi-destination traffic. However, 139 the statement c) above is not always true and multicast applications 140 are required in many use-cases. 142 When the multicast sources are attached to NVEs residing in 143 hypervisors or low-performance-replication TORs, the ingress 144 replication of a large amount of multicast traffic to a significant 145 number of remote NVEs/PEs can seriously degrade the performance of 146 the NVE and impact the application. 148 This document describes a solution that makes use of two IR 149 optimizations: 151 i) Assisted-Replication (AR) 152 ii) Pruned-Flood-Lists (PFL) 154 Both optimizations may be used together or independently so that the 155 performance and efficiency of the network to transport multicast can 156 be improved. Both solutions require some extensions to [EVPN] that 157 are described in section 3. 159 Section 2 lists the requirements of the combined optimized-IR 160 solution, whereas sections 4 and 5 describe the Assisted-Replication 161 (AR) solution, and section 6 the Pruned-Flood-Lists (PFL) solution. 163 2. Solution requirements 165 The IR optimization solution (optimized-IR hereafter) MUST meet the 166 following requirements: 168 a) The solution MUST provide an IR optimization for BM (Broadcast and 169 Multicast) traffic, while preserving the packet order for unicast 170 applications, i.e. known and unknown unicast traffic SHALL follow 171 the same path. 173 b) The solution MUST be compatible with [EVPN] and [EVPN-OVERLAY] and 174 not have any impact on the EVPN procedures for BM traffic. In 175 particular, the solution MUST support the following EVPN 176 functions: 178 o All-active multi-homing, including the split-horizon and 179 Designated Forwarder (DF) functions. 181 o Single-active multi-homing, including the DF function. 183 o Handling of multi-destination traffic and processing of 184 broadcast and multicast as per [EVPN]. 186 c) The solution MUST be backwards compatible with existing NVEs using 187 a non-optimized version of IR. A given EVI can have NVEs/PEs 188 supporting regular-IR and optimized-IR. 190 d) The solution MUST be independent of the NVO specific data plane 191 encapsulation and the virtual identifiers being used, e.g.: VXLAN 192 VNIs, NVGRE VSIDs or MPLS labels. 194 3. EVPN BGP Attributes for optimized-IR 196 This solution proposes some changes to the [EVPN] Inclusive Multicast 197 Ethernet Tag routes and attributes so that an NVE/PE can signal its 198 optimized-IR capabilities. 200 The Inclusive Multicast Ethernet Tag route (RT-3) and its PMSI Tunnel 201 Attribute's (PTA) general format used in [EVPN] are shown below: 203 +---------------------------------+ 204 | RD (8 octets) | 205 +---------------------------------+ 206 | Ethernet Tag ID (4 octets) | 207 +---------------------------------+ 208 | IP Address Length (1 octet) | 209 +---------------------------------+ 210 | Originating Router's IP Addr | 211 | (4 or 16 octets) | 212 +---------------------------------+ 214 +---------------------------------+ 215 | Flags (1 octet) | 216 +---------------------------------+ 217 | Tunnel Type (1 octets) | 218 +---------------------------------+ 219 | MPLS Label (3 octets) | 220 +---------------------------------+ 221 | Tunnel Identifier (variable) | 222 +---------------------------------+ 224 The Flags field is defined as follows: 226 0 1 2 3 4 5 6 7 227 +-+-+-+-+-+--+-+-+ 228 |rsved| T |BM|U|L| 229 +-+-+-+-+-+--+-+-+ 231 Where a new type field (for AR) and two new flags (for PFL signaling) 232 are defined: 234 - T is the AR Type field (2 bits) that defines the AR role of the 235 advertising router: 237 + 00 (decimal 0) = RNVE (non-AR support) 239 + 01 (decimal 1) = AR-REPLICATOR 241 + 10 (decimal 2) = AR-LEAF 243 - The PFL (Pruned-Flood-Lists) flags defined the desired behavior of 244 the advertising router for the different types of traffic: 246 + BM= Broadcast and Multicast (BM) flag. BM=1 means "prune-me" from 247 the BM flooding list. BM=0 means regular behavior. 249 + U= Unknown flag. U=1 means "prune-me" from the Unknown flooding 250 list. U=0 means regular behavior. 252 - Flag L is an existing flag defined in [RFC6514] (L=Leaf Information 253 Required) and it will be used only in the Selective AR Solution. 255 Please refer to section 10 for the IANA considerations related to the 256 PTA flags. 258 In this document, the above RT-3 and PTA can be used in three 259 different modes for the same EVI/Ethernet Tag: 261 o Regular-IR route: in this route, Originating Router's IP Address, 262 Tunnel Type (0x06), MPLS Label, Tunnel Identifier and Flags MUST be 263 used as described in [EVPN]. The Originating Router's IP Address 264 and Tunnel Identifier are set to an IP address that we denominate 265 IR-IP in this document. 267 o Replicator-AR route: this route is used by the AR-REPLICATOR to 268 advertise its AR capabilities, with the fields set as follows. 270 + Originating Router's IP Address as well as the Tunnel Identifier 271 are set to the same routable IP address that we denominate AR-IP 272 and SHOULD be different than the IR-IP for a given PE/NVE. 274 + Tunnel Type = Assisted-Replication (AR). Section 11 provides the 275 allocated type value. 277 + T (AR role type) = 01 (AR-REPLICATOR). 279 + L (Leaf Information Required) = 0 (for non-selective AR) or 1 280 (for selective AR). 282 o Leaf-AR route: this route MAY be used by the AR-LEAF to advertise 283 its desire to receive the multicast traffic from a specific AR- 284 REPLICATOR. It is only used for selective AR and its fields are set 285 as follows: 287 + Originating Router's IP Address is set to the advertising IR-IP 288 (same IP used by the AR-LEAF in regular-IR routes). 290 + Tunnel Identifier is set to the AR-IP of the AR-REPLICATOR from 291 which the multicast traffic is requested. 293 + Tunnel Type = Assisted-Replication (AR). Section 11 provides the 294 allocated type value. 296 + T (AR role type) = 02 (AR-LEAF). 298 Each AR-enabled node MUST understand and process the AR type field in 299 the PTA (Flags field) of replicator-AR and leaf-AR routes, and MUST 300 signal the corresponding type (1 or 2) according to its 301 administrative choice for replicator-AR and leaf-AR routes. 303 Each node, part of the EVI, MAY understand and process the BM/U 304 flags. Note that these BM/U flags may be used to optimize the 305 delivery of multi-destination traffic and its use SHOULD be an 306 administrative choice, and independent of the AR role. 308 Non-optimized-IR nodes will be unaware of the new PMSI attribute flag 309 definition as well as the new Tunnel Type (AR), i.e. they will ignore 310 the information contained in the flags field for any RT-3 and will 311 ignore the RT-3 routes with an unknown Tunnel Type (type AR in this 312 case). 314 4. Non-selective Assisted-Replication (AR) Solution Description 316 The following figure illustrates an example NVO network where the 317 non-selective AR function is enabled. Three different roles are 318 defined for a given EVI: AR-REPLICATOR, AR-LEAF and RNVE (Regular 319 NVE). The solution is called "non-selective" because the chosen AR- 320 REPLICATOR for a given flow MUST replicate the multicast traffic to 321 'all' the NVE/PEs in the EVI except for the source NVE/PE. 323 ( ) 324 (_ WAN _) 325 +---(_ _)----+ 326 | (_ _) | 327 PE1 | PE2 | 328 +------+----+ +----+------+ 329 TS1--+ (EVI-1) | | (EVI-1) +--TS2 330 |REPLICATOR | |REPLICATOR | 331 +--------+--+ +--+--------+ 332 | | 333 +--+----------------+--+ 334 | | 335 | | 336 +----+ VXLAN/nvGRE/MPLSoGRE +----+ 337 | | IP Fabric | | 338 | | | | 339 NVE1 | +-----------+----------+ | NVE3 340 Hypervisor| TOR | NVE2 |Hypervisor 341 +---------+-+ +-----+-----+ +-+---------+ 342 | (EVI-1) | | (EVI-1) | | (EVI-1) | 343 | LEAF | | RNVE | | LEAF | 344 +--+-----+--+ +--+-----+--+ +--+-----+--+ 345 | | | | | | 346 VM11 VM12 TS3 TS4 VM31 VM32 348 Figure 1 Optimized-IR scenario 350 4.1. Non-selective AR-REPLICATOR procedures 352 An AR-REPLICATOR is defined as an NVE/PE capable of replicating 353 ingress BM (Broadcast and Multicast) traffic received on an overlay 354 tunnel to other overlay tunnels and local Attachment Circuits (ACs). 355 The AR-REPLICATOR signals its role in the control plane and 356 understands where the other roles (AR-LEAF nodes, RNVEs and other AR- 357 REPLICATORs) are located. A given AR-enabled EVI service may have 358 zero, one or more AR-REPLICATORs. In our example in figure 1, PE1 and 359 PE2 are defined as AR-REPLICATORs. The following considerations apply 360 to the AR-REPLICATOR role: 362 a) The AR-REPLICATOR role SHOULD be an administrative choice in any 363 NVE/PE that is part of an AR-enabled EVI. This administrative 364 option to enable AR-REPLICATOR capabilities MAY be implemented as 365 a system level option as opposed to as a per-EVI option. 367 b) An AR-REPLICATOR MUST advertise a Replicator-AR route and MAY 368 advertise a Regular-IR route. The AR-REPLICATOR MUST NOT generate 369 a Regular-IR route if it does not have local attachment circuits 370 (AC). 372 c) The Replicator-AR and Regular-IR routes will be generated 373 according to section 3. The AR-IP and IR-IP used by the 374 Replicator-AR will be different routable IP addresses. 376 d) When a node defined as AR-REPLICATOR receives a packet on an 377 overlay tunnel, it will do a tunnel destination IP lookup and 378 apply the following procedures: 380 o If the destination IP is the AR-REPLICATOR IR-IP Address the 381 node will process the packet normally as in [EVPN]. 383 o If the destination IP is the AR-REPLICATOR AR-IP Address the 384 node MUST replicate the packet to local ACs and overlay 385 tunnels (excluding the overlay tunnel to the source of the 386 packet). When replicating to remote AR-REPLICATORs the tunnel 387 destination IP will be an IR-IP. That will be an indication 388 for the remote AR-REPLICATOR that it MUST NOT replicate to 389 overlay tunnels. The tunnel source IP will be the AR-IP of the 390 AR-REPLICATOR. 392 4.2. Non-selective AR-LEAF procedures 394 AR-LEAF is defined as an NVE/PE that - given its poor replication 395 performance - sends all the BM traffic to an AR-REPLICATOR that can 396 replicate the traffic further on its behalf. It MAY signal its AR- 397 LEAF capability in the control plane and understands where the other 398 roles are located (AR-REPLICATOR and RNVEs). A given service can have 399 zero, one or more AR-LEAF nodes. Figure 1 shows NVE1 and NVE2 (both 400 residing in hypervisors) acting as AR-LEAF. The following 401 considerations apply to the AR-LEAF role: 403 a) The AR-LEAF role SHOULD be an administrative choice in any NVE/PE 404 that is part of an AR-enabled EVI. This administrative option to 405 enable AR-LEAF capabilities MAY be implemented as a system level 406 option as opposed to as per-EVI option. 408 b) In this non-selective AR solution, the AR-LEAF MUST advertise a 409 single Regular-IR inclusive multicast route as in [EVPN]. 411 c) In a service where there are no AR-REPLICATORs, the AR-LEAF MUST 412 use regular ingress replication. This will happen when a new 413 update from the last former AR-REPLICATOR is received and contains 414 a non-REPLICATOR AR type, or when the AR-LEAF detects that the 415 last AR-REPLICATOR is down (next-hop tracking in the IGP or any 416 other detection mechanism). Ingress replication MUST use the 417 forwarding information given by the remote Regular-IR Inclusive 418 Multicast Routes as described in [EVPN]. 420 d) In a service where there is one or more AR-REPLICATORs (based on 421 the received Replicator-AR routes for the EVI), the AR-LEAF can 422 locally select which AR-REPLICATOR it sends the BM traffic to: 424 o A single AR-REPLICATOR MAY be selected for all the BM packets 425 received on the AR-LEAF attachment circuits (ACs) for a given 426 EVI. This selection is a local decision and it does not have 427 to match other AR-LEAF's selection within the same EVI. 429 o An AR-LEAF MAY select more than one AR-REPLICATOR and do 430 either per-flow or per-EVI load balancing. 432 o In case of a failure on the selected AR-REPLICATOR, another 433 AR-REPLICATOR will be selected. 435 o When an AR-REPLICATOR is selected, the AR-LEAF MUST send all 436 the BM packets to that AR-REPLICATOR using the forwarding 437 information given by the Replicator-AR route for the chosen 438 AR-REPLICATOR, with tunnel type = TBD (AR tunnel). The 439 underlay destination IP address MUST be the AR-IP advertised 440 by the AR-REPLICATOR in the Replicator-AR route. 442 o AR-LEAF nodes SHALL send service-level BM control plane 443 packets following regular IR procedures. An example would be 444 IGMP, MLD or PIM multicast packets. The AR-REPLICATORs MUST 445 not replicate these control plane packets to other overlay 446 tunnels since they will use the regular IR-IP Address. 448 4.3. RNVE procedures 450 RNVE (Regular Network Virtualization Edge node) is defined as an 451 NVE/PE without AR-REPLICATOR or AR-LEAF capabilities that does IR as 452 described in [EVPN]. The RNVE does not signal any AR role and is 453 unaware of the AR-REPLICATOR/LEAF roles in the EVI. The RNVE will 454 ignore the Flags in the Regular-IR routes and will ignore the 455 Replicator-AR and Leaf-AR routes entirely (due to an unknown tunnel 456 type in the PTA). 458 This role provides EVPN with the backwards compatibility required in 459 optimized-IR EVIs. Figure 1 shows NVE2 as RNVE. 461 4.4. Forwarding behavior in non-selective AR EVIs 463 In AR EVIs, BM (Broadcast and Multicast) traffic between two NVEs may 464 follow a different path than unicast traffic. This solution proposes 465 the replication of BM through the AR-REPLICATOR node, whereas 466 unknown/known unicast will be delivered directly from the source node 467 to the destination node without being replicated by any intermediate 468 node. Unknown unicast SHALL follow the same path as known unicast 469 traffic in order to avoid packet reordering for unicast applications 470 and simplify the control and data plane procedures. Section 4.4.1. 471 describes the expected forwarding behavior for BM traffic in nodes 472 acting as AR-REPLICATOR, AR-LEAF and RNVE. Section 4.4.2. describes 473 the forwarding behavior for unknown unicast traffic. 475 Note that known unicast forwarding is not impacted by this solution. 477 4.4.1. Broadcast and Multicast forwarding behavior 479 The expected behavior per role is described in this section. 481 4.4.1.1. Non-selective AR-REPLICATOR BM forwarding 483 The AR-REPLICATORs will build a flooding list composed of ACs and 484 overlay tunnels to remote nodes in the EVI. Some of those overlay 485 tunnels MAY be flagged as non-BM receivers based on the BM flag 486 received from the remote nodes in the EVI. 488 o When an AR-REPLICATOR receives a BM packet on an AC, it will 489 forward the BM packet to its flooding list (including local ACs and 490 remote NVE/PEs), skipping the non-BM overlay tunnels. 492 o When an AR-REPLICATOR receives a BM packet on an overlay tunnel, it 493 will check the destination IP of the underlay IP header and: 495 - If the destination IP matches its AR-IP, the AR-REPLICATOR will 496 forward the BM packet to its flooding list (ACs and overlay 497 tunnels) excluding the non-BM overlay tunnels. The AR-REPLICATOR 498 will do source squelching to ensure the traffic is not sent back 499 to the originating AR-LEAF. If the overlay encapsulation is MPLS 500 and the EVI label is not the bottom of the stack, the AR- 501 REPLICATOR MUST copy the rest of the labels and forward them to 502 the egress overlay tunnels. 504 - If the destination IP matches its IR-IP, the AR-REPLICATOR will 505 skip all the overlay tunnels from the flooding list, i.e. it 506 will only replicate to local ACs. This is the regular IR 507 behavior described in [EVPN]. 509 4.4.1.2. Non-selective AR-LEAF BM forwarding 510 The AR-LEAF nodes will build two flood-lists: 512 1) Flood-list #1 - composed of ACs and an AR-REPLICATOR-set of 513 overlay tunnels. The AR-REPLICATOR-set is defined as one or more 514 overlay tunnels to the AR-IP Addresses of the remote AR- 515 REPLICATOR(s) in the EVI. The selection of more than one AR- 516 REPLICATOR is described in section 4.2. and it is a local AR- 517 LEAF decision. 519 2) Flood-list #2 - composed of ACs and overlay tunnels to the 520 remote IR-IP Addresses. 522 When an AR-LEAF receives a BM packet on an AC, it will check the 523 AR-REPLICATOR-set: 525 o If the AR-REPLICATOR-set is empty, the AR-LEAF will send the packet 526 to flood-list #2. 528 o If the AR-REPLICATOR-set is NOT empty, the AR-LEAF will send the 529 packet to flood-list #1, where only one of the overlay tunnels of 530 the AR-REPLICATOR-set is used. 532 When an AR-LEAF receives a BM packet on an overlay tunnel, will 533 forward the BM packet to its local ACs and never to an overlay 534 tunnel. This is the regular IR behavior described in [EVPN]. 536 4.4.1.3. RNVE BM forwarding 538 The RNVE is completely unaware of the AR-REPLICATORs, AR-LEAF nodes 539 and BM/U flags (that information is ignored). Its forwarding behavior 540 is the regular IR behavior described in [EVPN]. Any regular non-AR 541 node is fully compatible with the RNVE role described in this 542 document. 544 4.4.2. Unknown unicast forwarding behavior 546 The expected behavior is described in this section. 548 4.4.2.1. Non-selective AR-REPLICATOR/LEAF Unknown unicast forwarding 550 While the forwarding behavior in AR-REPLICATORs and AR-LEAF nodes is 551 different for BM traffic, as far as Unknown unicast traffic 552 forwarding is concerned, AR-LEAF nodes behave exactly in the same way 553 as AR-REPLICATORs do. 555 The AR-REPLICATOR/LEAF nodes will build a flood-list composed of ACs 556 and overlay tunnels to the IR-IP Addresses of the remote nodes in the 557 EVI. Some of those overlay tunnels MAY be flagged as non-U (Unknown 558 unicast) receivers based on the U flag received from the remote nodes 559 in the EVI. 561 o When an AR-REPLICATOR/LEAF receives an unknown packet on an AC, it 562 will forward the unknown packet to its flood-list, skipping the 563 non-U overlay tunnels. 565 o When an AR-REPLICATOR/LEAF receives an unknown packet on an overlay 566 tunnel will forward the unknown packet to its local ACs and never 567 to an overlay tunnel. This is the regular IR behavior described in 568 [EVPN]. 570 4.4.2.2. RNVE Unknown unicast forwarding 572 As described for BM traffic, the RNVE is completely unaware of the 573 REPLICATORs, LEAF nodes and BM/U flags (that information is ignored). 574 Its forwarding behavior is the regular IR behavior described in 575 [EVPN], also for Unknown unicast traffic. Any regular non-AR node is 576 fully compatible with the RNVE role described in this document. 578 5. Selective Assisted-Replication (AR) Solution Description 580 Figure 1 is also used to describe the selective AR solution, however 581 in this section we consider NVE2 as one more AR-LEAF for EVI-1. The 582 solution is called "selective" because a given AR-REPLICATOR MUST 583 replicate the BM traffic to only the AR-LEAF that requested the 584 replication (as opposed to all the AR-LEAF nodes) and MAY replicate 585 the BM traffic to the RNVEs. The same AR roles defined in section 4 586 are used here, however the procedures are slightly different. 588 The following sub-sections describe the differences in the procedures 589 of AR-REPLICATOR/LEAFs compared to the non-selective AR solution. 590 There is no change on the RNVEs. 592 5.1. Selective AR-REPLICATOR procedures 594 In our example in figure 1, PE1 and PE2 are defined as Selective AR- 595 REPLICATORs. The following considerations apply to the Selective AR- 596 REPLICATOR role: 598 a) The Selective AR-REPLICATOR capability SHOULD be an administrative 599 choice in any NVE/PE that is part of an AR-enabled EVI, as the AR 600 role itself. This administrative option MAY be implemented as a 601 system level option as opposed to as a per-EVI option. 603 b) Each AR-REPLICATOR will build a list of AR-REPLICATOR, AR-LEAF and 604 RNVE nodes (AR-LEAF nodes that sent only a regular-IR route are 605 accounted as RNVEs by the AR-REPLICATOR). In spite of the 606 'Selective' administrative option, an AR-REPLICATOR MUST NOT 607 behave as a Selective AR-REPLICATOR if at least one of the AR- 608 REPLICATORs has the L flag NOT set. If at least one AR-REPLICATOR 609 sends a Replicator-AR route with L=0 (in the EVI context), the 610 rest of the AR-REPLICATORs will fall back to non-selective AR 611 mode. 613 b) The Selective AR-REPLICATOR MUST follow the procedures described 614 in section 4.1, except for the following differences: 616 o The Replicator-AR route MUST include L=1 (Leaf Information 617 Required) in the Replicator-AR route. This flag is used by the 618 AR-REPLICATORs to advertise their 'selective' AR-REPLICATOR 619 capabilities. 621 o The AR-REPLICATOR will build a 'selective' AR-LEAF-set with 622 the list of nodes that requested replication to its own AR-IP. 623 For instance, assuming NVE1 and NVE2 advertise a Leaf-AR route 624 with PE1's AR-IP (as Tunnel Identifier) and NVE3 advertises a 625 Leaf-AR route with PE2's AR-IP, PE1 MUST only add NVE1/NVE2 in 626 its selective AR-LEAF-set for EVI-1, and exclude NVE3. 628 o When a node defined and operating as Selective AR-REPLICATOR 629 receives a packet on an overlay tunnel, it will do a tunnel 630 destination IP lookup and if the destination IP is the AR- 631 REPLICATOR AR-IP Address, the node MUST replicate the packet 632 to: 634 + local ACs 635 + overlay tunnels in the Selective AR-LEAF-set (excluding the 636 overlay tunnel to the source AR-LEAF). 637 + overlay tunnels to the RNVEs if the tunnel source IP is the 638 IR-IP of an AR-LEAF (in any other case, the AR-REPLICATOR 639 MUST NOT replicate the BM traffic to remote RNVEs). In other 640 words, the first-hop selective AR-REPLICATOR will replicate 641 to all the RNVEs. 642 + overlay tunnels to the remote Selective AR-REPLICATORs if 643 the tunnel source IP is the IR-IP of its own AR-LEAF-set (in 644 any other case, the AR-REPLICATOR MUST NOT replicate the BM 645 traffic to remote AR-REPLICATORs), where the tunnel 646 destination IP is the AR-IP of the remote Selective AR- 647 REPLICATOR. The tunnel destination IP AR-IP will be an 648 indication for the remote Selective AR-REPLICATOR that the 649 packet needs further replication to its AR-LEAFs. 651 5.2. Selective AR-LEAF procedures 653 A Selective AR-LEAF chooses a single Selective AR-REPLICATOR per EVI 654 and: 656 o Sends all the EVI BM traffic to that AR-REPLICATOR and 657 o Expects to receive the BM traffic for a given EVI from the same AR- 658 REPLICATOR. 660 In the example of Figure 1, we consider that NVE1/NVE2/NVE3 as 661 Selective AR-LEAFs. NVE1 selects PE1 as its Selective AR-REPLICATOR. 662 If that is so, NVE1 will send all its BM traffic for EVI-1 to PE1. If 663 other AR-LEAF/REPLICATORs send BM traffic, NVE1 will receive that 664 traffic from PE1. These are the differences in the behavior of a 665 Selective AR-LEAF compared to a non-selective AR-LEAF: 667 a) The AR-LEAF role selective capability SHOULD be an administrative 668 choice in any NVE/PE that is part of an AR-enabled EVI. This 669 administrative option to enable AR-LEAF capabilities MAY be 670 implemented as a system level option as opposed to as per-EVI 671 option. 673 b) The AR-LEAF MAY advertise a Regular-IR route if there are RNVEs or 674 non-selective AR-LEAFs in the EVI. The Selective AR-LEAF MUST 675 advertise a Leaf-AR route after receiving a Replicator-AR route 676 with L=1. It is recommended that the Selective AR-LEAF waits for a 677 timer t before sending the Leaf-AR route, so that the AR-LEAF 678 receives all the Replicator-AR routes for the EVI. 680 c) In a service where there is more than one Selective AR-REPLICATORs 681 the Selective AR-LEAF MUST locally select a single Selective AR- 682 REPLICATOR for the EVI. Once selected: 684 o The Selective AR-LEAF will send a Leaf-AR route including the 685 AR-IP of the selected AR-REPLICATOR. 687 o The Selective AR-LEAF will send all the BM packets received on 688 the attachment circuits (ACs) for a given EVI to that AR- 689 REPLICATOR. 691 o In case of a failure on the selected AR-REPLICATOR, another 692 AR-REPLICATOR will be selected and a new Leaf-AR update will 693 be issued, including the new AR-IP. This new route will update 694 the selective list in the new Selective AR-REPLICATOR. In case 695 of failure on the active Selective AR-REPLICATOR, it is 696 recommended for the Selective AR-LEAF to revert to IR behavior 697 for a timer t to speed up the convergence. When the timer 698 expires, the Selective AR-LEAF will resume its AR mode with 699 the new Selective AR-REPLICATOR. 701 5.3. Forwarding behavior in selective AR EVIs 703 This section describes the differences of the selective AR forwarding 704 mode compared to the non-selective mode. Compared to section 4.4, 705 there are no changes for the forwarding behavior in RNVEs or for 706 unknown unicast traffic. 708 5.3.1. Selective AR-REPLICATOR BM forwarding 710 The Selective AR-REPLICATORs will build two flood-lists: 712 1) Flood-list #1 - composed of ACs and overlay tunnels to the 713 remote nodes in the EVI, always using the IR-IPs in the tunnel 714 destination IP addresses. Some of those overlay tunnels MAY be 715 flagged as non-BM receivers based on the BM flag received from 716 the remote nodes in the EVI. 718 2) Flood-list #2 - composed of ACs, a Selective AR-LEAF-set and a 719 Selective AR-REPLICATOR-set, where: 721 o The Selective AR-LEAF-set is composed of the overlay tunnels 722 to the AR-LEAFs that advertise a Leaf-AR route with the AR-IP 723 of the local AR-REPLICATOR. This set is updated with every 724 Leaf-AR route received with a change in the AR-IP included in 725 the PTA's Tunnel Identifier. 727 o The Selective AR-REPLICATOR-set is composed of the overlay 728 tunnels to all the AR-REPLICATORs that send a Replicator-AR 729 route with L=1. The AR-IP addresses are used as tunnel 730 destination IP. 732 When a Selective AR-REPLICATOR receives a BM packet on an AC, it will 733 forward the BM packet to its flood-list #1, skipping the non-BM 734 overlay tunnels. 736 When a Selective AR-REPLICATOR receives a BM packet on an overlay 737 tunnel, it will check the destination and source IPs of the underlay 738 IP header and: 740 - If the destination IP matches its AR-IP and the source IP 741 matches an IP of its own Selective AR-LEAF-set, the AR- 742 REPLICATOR will forward the BM packet to its flood-list #2, as 743 long as the list of AR-REPLICATORs for the EVI matches the 744 Selective AR-REPLICATOR-set. If the Selective AR-REPLICATOR-set 745 does not match the list of AR-REPLICATORs, the node reverts back 746 to non-selective mode and flood-list #1 is used. 748 - If the destination IP matches its AR-IP and the source IP does 749 not match any IP of its Selective AR-LEAF-set, the AR-REPLICATOR 750 will forward the BM packet to flood-list #2 but skipping the AR- 751 REPLICATOR-set. 753 - If the destination IP matches its IR-IP, the AR-REPLICATOR will 754 use flood-list #1 but MUST skip all the overlay tunnels from the 755 flooding list, i.e. it will only replicate to local ACs. This is 756 the regular-IR behavior described in [EVPN]. 758 In any case, non-BM overlay tunnels are excluded from flood-lists and 759 also source squelching is always done in order to ensure the traffic 760 is not sent back to the originating source. If the overlay 761 encapsulation is MPLS and the EVI label is not the bottom of the 762 stack, the AR-REPLICATOR MUST copy the rest of the labels when 763 forwarding them to the egress overlay tunnels. 765 5.3.2. Selective AR-LEAF BM forwarding 767 The Selective AR-LEAF nodes will build two flood-lists: 769 1) Flood-list #1 - composed of ACs and the overlay tunnel to the 770 selected AR-REPLICATOR (using the AR-IP as the tunnel 771 destination IP). 773 2) Flood-list #2 - composed of ACs and overlay tunnels to the 774 remote IR-IP Addresses. 776 When an AR-LEAF receives a BM packet on an AC, it will check if there 777 is any selected AR-REPLICATOR. If there is, flood-list #1 will be 778 used. Otherwise, flood-list #2 will. 780 When an AR-LEAF receives a BM packet on an overlay tunnel, will 781 forward the BM packet to its local ACs and never to an overlay 782 tunnel. This is the regular IR behavior described in [EVPN]. 784 6. Pruned-Flood-Lists (PFL) 786 In addition to AR, the second optimization supported by this solution 787 is the ability for the all the EVI nodes to signal Pruned-Flood-Lists 788 (PFL). As described in section 3, an EVPN node can signal a given 789 value for the BM and U PFL flags in the IR Inclusive Multicast 790 Routes, where: 792 + BM= Broadcast and Multicast (BM) flag. BM=1 means "prune-me" from 793 the BM flood-list. BM=0 means regular behavior. 795 + U= Unknown flag. U=1 means "prune-me" from the Unknown flood-list. 796 U=0 means regular behavior. 798 The ability to signal these PFL flags is an administrative choice. 799 Upon receiving a non-zero PFL flag, a node MAY decide to honor the 800 PFL flag and remove the sender from the corresponding flood-list. A 801 given EVI node receiving BUM traffic on an overlay tunnel MUST 802 replicate the traffic normally, regardless of the signaled PFL 803 flags. 805 This optimization MAY be used along with the AR solution. 807 6.1. A PFL example 809 In order to illustrate the use of the solution described in this 810 document, we will assume that EVI-1 in figure 1 is optimized-IR 811 enabled and: 813 o PE1 and PE2 are administratively configured as AR-REPLICATORs, due 814 to their high-performance replication capabilities. PE1 and PE2 815 will send a Replicator-AR route with BM/U flags = 00. 817 o NVE1 and NVE3 are administratively configured as AR-LEAF nodes, due 818 to their low-performance software-based replication capabilities. 819 They will advertise a Leaf-AR route. Assuming both NVEs advertise 820 all the attached VMs in EVPN as soon as they come up and don't have 821 any VMs interested in multicast applications, they will be 822 configured to signal BM/U flags = 11 for EVI-1. 824 o NVE2 is optimized-IR unaware; therefore it takes on the RNVE role 825 in EVI-1. 827 Based on the above assumptions the following forwarding behavior will 828 take place: 830 (1) Any BM packets sent from VM11 will be sent to VM12 and PE1. PE1 831 will forward further the BM packets to TS1, WAN link, PE2 and 832 NVE2, but not to NVE3. PE2 and NVE2 will replicate the BM packets 833 to their local ACs but we will avoid NVE3 having to replicate 834 unnecessarily those BM packets to VM31 and VM32. 836 (2) Any BM packets received on PE2 from the WAN will be sent to PE1 837 and NVE2, but not to NVE1 and NVE3, sparing the two hypervisors 838 from replicating unnecessarily to their local VMs. PE1 and NVE2 839 will replicate to their local ACs only. 841 (3) Any Unknown unicast packet sent from VM31 will be forwarded by 842 NVE3 to NVE2, PE1 and PE2 but not NVE1. The solution avoids the 843 unnecessary replication to NVE1, since the destination of the 844 unknown traffic cannot be at NVE1. 846 (4) Any Unknown unicast packet sent from TS1 will be forwarded by PE1 847 to the WAN link, PE2 and NVE2 but not to NVE1 and NVE3, since the 848 target of the unknown traffic cannot be at those NVEs. 850 7. AR Procedures for single-IP AR-REPLICATORS 852 The procedures explained in sections 4 (Non-selective AR) and 5 853 (Selective AR) assume that the AR-REPLICATOR can use two local 854 routable IP addresses to terminate and initiate NVO tunnels, i.e. IR- 855 IP and AR-IP addresses. This is usually the case for PE-based AR- 856 REPLICATOR nodes. 858 In some cases, the AR-REPLICATOR node does not support more than one 859 IP address to terminate and initiate NVO tunnels, i.e. the IR-IP and 860 AR-IP are the same IP addresses. This may be the case in some 861 software-based or low-end AR-REPLICATOR nodes. If this is the case, 862 the procedures in sections 4 and 5 must be modified in the following 863 way: 865 o The Replicator-AR routes generated by the AR-REPLICATOR use an AR- 866 IP that will match its IR-IP. In order to differentiate the data 867 plane packets that need to use IR from the packets that must use AR 868 forwarding mode, the Replicator-AR route must advertise a different 869 VNI/VSID than the one used by the Regular-IR route. For instance, 870 the AR-REPLICATOR will advertise AR-VNI along with the Replicator- 871 AR route and IR-VNI along with the Regular-IR route. Since both 872 routes have the same key, different RDs are needed for both routes. 874 o An AR-REPLICATOR will perform IR or AR forwarding mode for the 875 incoming Overlay packets based on an ingress VNI lookup, as opposed 876 to the tunnel IP DA lookup described in sections 4 and 5. Note 877 that, when replicating to remote AR-REPLICATOR nodes, the use of 878 the IR-VNI or AR-VNI advertised by the egress node will determine 879 the IR or AR forwarding mode at the subsequent AR-REPLICATOR. 881 The rest of the procedures will follow what is described in sections 882 4 and 5. 884 8. AR Procedures and EVPN Multi-homing Split-Horizon 886 When EVPN is used for MPLS over GRE, all the multi-homing procedures 887 are compatible with sections 4 and 5 of this document. 889 If VXLAN or NVGRE are used, and if the Split-horizon is based on the 890 tunnel IP SA and "Local-Bias" as described in [EVPN-OVERLAY], the 891 Split-horizon check will not work if there is an Ethernet-Segment 892 shared between two AR-LEAF nodes, and the AR-REPLICATOR changes the 893 tunnel IP SA of the packets with its own AR-IP. 895 In order to be compatible with the IP SA split-horizon check, the AR- 896 REPLICATOR MAY keep the original received tunnel IP SA when 897 replicating packets to a remote AR-LEAF or AR-REPLICATOR. This will 898 allow DF (Designated Forwarder) AR-LEAF nodes to apply Split-horizon 899 check procedures for BM packets, before sending them to the local 900 Ethernet-Segment. 902 Note that if the AR-REPLICATOR implementation keeps the received 903 tunnel IP SA, the use of uRPF in the IP fabric based on the tunnel IP 904 SA MUST be disabled. 906 9. Out-of-band distribution of Broadcast/Multicast traffic 908 The use of out-of-band mechanisms to distribute BM traffic between 909 AR-REPLICATORS MAY be used. Details will be provided in future 910 versions of this document. 912 10. Benefits of the optimized-IR solution 914 A solution for the optimization of Ingress Replication in EVPN is 915 described in this document (optimized-IR). The solution brings the 916 following benefits: 918 o Optimizes the multicast forwarding in low-performance NVEs, by 919 relaying the replication to high-performance NVEs (AR-REPLICATORs) 920 and while preserving the packet ordering for unicast applications. 922 o Reduces the flooded traffic in NVO networks where some NVEs do not 923 need broadcast/multicast and/or unknown unicast traffic. 925 o It is fully compatible with existing EVPN implementations and EVPN 926 functions for NVO overlay tunnels. Optimized-IR NVEs and regular 927 NVEs can be even part of the same EVI. 929 o It does not require any PIM-based tree in the NVO core of the 930 network. 932 11. Conventions used in this document 933 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 934 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 935 document are to be interpreted as described in RFC-2119 [RFC2119]. 937 In this document, these words will appear with that interpretation 938 only when in ALL CAPS. Lower case uses of these words are not to be 939 interpreted as carrying RFC-2119 significance. 941 In this document, the characters ">>" preceding an indented line(s) 942 indicates a compliance requirement statement using the key words 943 listed above. This convention aids reviewers in quickly identifying 944 or finding the explicit compliance requirements of this RFC. 946 12. Security Considerations 948 This section will be added in future versions. 950 13. IANA Considerations 952 A new Tunnel-Type (AR) must be requested and allocated by IANA for 953 the PTA (PMSI Tunnel Attribute) used in this document. 955 In addition to the new Tunnel-Type, this document requests the 956 allocation of the PTA flags as in section 3. A registry is created as 957 per [PTA-FLAGS]. 959 14. Terminology 961 Regular-IR: Refers to Regular Ingress Replication, where the source 962 NVE/PE sends a copy to each remote NVE/PE part of the EVI. 964 AR-IP: IP address owned by the AR-REPLICATOR and used to 965 differentiate the ingress traffic that must follow the AR 966 procedures. 968 IR-IP: IP address used for Ingress Replication as in [EVPN]. 970 AR-VNI: VNI advertised by the AR-REPLICATOR along with the 971 Replicator-AR route. It is used to identify the ingress 972 packets that must follow AR procedures ONLY in the Single-IP 973 AR-REPLICATOR case. 975 IR-VNI: VNI advertised along with the RT-3 for IR. 977 AR forwarding mode: for an AR-LEF, it means sending an AC BM packet 978 to a single AR-REPLICATOR with tunnel destination IP AR-IP. 979 For an AR-REPLICATOR, it means sending a BM packet to a 980 selective number or all the overlay tunnels when the packet 981 was previously received from an overlay tunnel. 983 IR forwarding mode: it refers to the Ingress Replication behavior 984 explained in [EVPN]. It means sending an AC BM packet copy to 985 each remote PE/NVE in the EVI and sending an overlay BM packet 986 only to the ACs and not other overlay tunnels. 988 PTA: PMSI Tunnel Attribute 990 RT-3: EVPN Route Type 3, Inclusive Multicast Ethernet Tag route 992 15. References 994 15.1 Normative References 996 [RFC6514]Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP 997 Encodings and Procedures for Multicast in MPLS/BGP IP VPNs", 998 RFC 6514, DOI 10.17487/RFC6514, February 2012, . 1001 [RFC7432]Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A., 1002 Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet 1003 VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015, . 1006 15.2 Informative References 1008 [EVPN-OVERLAY] Sajassi-Drake et al., "A Network Virtualization 1009 Overlay Solution using EVPN", draft-ietf-bess-evpn-overlay-01.txt, 1010 work in progress, February 2015 1012 [PTA-FLAGS] Rosen, E., "IANA Registry for P-Multicast Service 1013 Interface Tunnel Attribute Flags", draft-ietf-bess-pta-flags-00.txt, 1014 work in progress, February 2015 1016 16. Acknowledgments 1018 The authors would like to thank Neil Hart, David Motz, Thomas Morin 1019 and Jeffrey Zhang for their valuable feedback and contributions. 1021 17. Authors' Addresses 1022 Jorge Rabadan (Editor) 1023 Alcatel-Lucent 1024 777 E. Middlefield Road 1025 Mountain View, CA 94043 USA 1026 Email: jorge.rabadan@alcatel-lucent.com 1028 Senthil Sathappan 1029 Alcatel-Lucent 1030 Email: senthil.sathappan@alcatel-lucent.com 1032 Mukul Katiyar 1033 Juniper 1034 Email: mkatiyar@juniper.net 1036 Wim Henderickx 1037 Alcatel-Lucent 1038 Email: wim.henderickx@alcatel-lucent.com 1040 Ravi Shekhar 1041 Juniper Networks 1042 Email: rshekhar@juniper.net 1044 Nischal Sheth 1045 Juniper Networks 1046 Email: nsheth@juniper.net 1048 Wen Lin 1049 Juniper Networks 1050 Email: wlin@juniper.net 1052 Ali Sajassi 1053 Cisco 1054 Email: sajassi@cisco.com 1056 Aldrin Isaac 1057 Bloomberg 1058 Email: aisaac71@bloomberg.net 1060 Mudassir Tufail 1061 Citibank 1062 mudassir.tufail@citi.com