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Checking references for intended status: Experimental ---------------------------------------------------------------------------- No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group K. Vairavakkalai 3 Internet-Draft M. Jeyananth 4 Intended status: Experimental Juniper Networks, Inc. 5 Expires: December 13, 2021 June 11, 2021 7 BGP signalled MPLS-namespaces 8 draft-kaliraj-bess-bgp-sig-private-mpls-labels-02 10 Abstract 12 The MPLS-forwarding-layer in a core network is a shared resource. 13 The MPLS FIB at nodes in this layer contains labels that are 14 dynamically allocated and locally significant at that node. 16 For some usecases like upstream-label-allocation, it is useful to be 17 able to create virtual private MPLS-forwarding-layers over this 18 shared MPLS-forwarding-layer. This allows installing deterministic 19 private label-values in the private-FIBs created at nodes 20 participating in this private MPLS forwarding-layer, while preserving 21 the "locally significant" nature of the underlying shared 'public' 22 MPLS-forwarding-layer. 24 This specification describes the procedures to create such virtual 25 private MPLS-forwarding layers (private MPLS-planes) using a new BGP 26 family. And gives a few example use-cases on how this private 27 forwarding-layers can be used. 29 Requirements Language 31 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 32 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 33 document are to be interpreted as described in RFC 2119 [RFC2119]. 35 Status of This Memo 37 This Internet-Draft is submitted in full conformance with the 38 provisions of BCP 78 and BCP 79. 40 Internet-Drafts are working documents of the Internet Engineering 41 Task Force (IETF). Note that other groups may also distribute 42 working documents as Internet-Drafts. The list of current Internet- 43 Drafts is at https://datatracker.ietf.org/drafts/current/. 45 Internet-Drafts are draft documents valid for a maximum of six months 46 and may be updated, replaced, or obsoleted by other documents at any 47 time. It is inappropriate to use Internet-Drafts as reference 48 material or to cite them other than as "work in progress." 49 This Internet-Draft will expire on December 13, 2021. 51 Copyright Notice 53 Copyright (c) 2021 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (https://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 69 2. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 3 70 3. Constructs and building blocks . . . . . . . . . . . . . . . 4 71 3.1. Context Protocol Nexthop Address . . . . . . . . . . . . 4 72 3.2. MPLS context FIB . . . . . . . . . . . . . . . . . . . . 4 73 3.3. Context Label . . . . . . . . . . . . . . . . . . . . . . 5 74 3.4. Roles of nodes in a MPLS-plane . . . . . . . . . . . . . 5 75 3.4.1. Edge-nodes (PLER) . . . . . . . . . . . . . . . . . . 5 76 3.4.2. Transit-nodes (PLSR) . . . . . . . . . . . . . . . . 5 77 3.5. Sending traffic into the MPLS plane . . . . . . . . . . . 5 78 4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 79 5. BGP families, routes and encoding . . . . . . . . . . . . . . 7 80 5.1. New address-families . . . . . . . . . . . . . . . . . . 7 81 5.1.1. AFI: MPLS, SAFI: 128 . . . . . . . . . . . . . . . . 7 82 5.1.2. AFI: MPLS, SAFI: 1 . . . . . . . . . . . . . . . . . 8 83 5.2. Routes and Operational procedures . . . . . . . . . . . . 8 84 5.2.1. "Context-Nexthop" discovery route . . . . . . . . . . 8 85 5.2.2. "Private Label" routes . . . . . . . . . . . . . . . 9 86 6. Example of Usecases . . . . . . . . . . . . . . . . . . . . . 11 87 6.1. Mezanine transport layer in a Seamless-MPLS network . . . 11 88 6.2. Service Forwarding Helper usecase . . . . . . . . . . . . 11 89 6.3. Standard BGP API to a MPLS network's forwarding-plane . . 12 90 6.4. Traffic engineering and Security advantages . . . . . . . 12 91 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 92 8. Security Considerations . . . . . . . . . . . . . . . . . . . 13 93 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 94 10. Normative References . . . . . . . . . . . . . . . . . . . . 13 95 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 97 1. Introduction 99 The MPLS-forwarding-layer in a core network is a shared resource. 100 The MPLS FIB at nodes in this layer contains labels that are 101 dynamically allocated and locally significant at that node. 103 For some usecases like upstream-label-allocation, it is useful to be 104 able to create virtual private MPLS-forwarding-layers over this 105 shared MPLS-forwarding-layer. This allows installing deterministic 106 private label-values in the private-FIBs in this private forwarding- 107 layer, while preserving the "locally significant" nature of the 108 underlying shared 'public' MPLS-forwarding-layer. 110 It can be noted that, mechanism described in this document is nothing 111 but a [RFC4364] style BGP VPN where the FEC is MPLS-Label, instead of 112 IP-prefix. This document defines new address-families (AFI: MPLS, 113 SAFI: VPN-Unicast, Unicast) and associated signaling mechanisms to 114 create and use MPLS forwarding-contexts in a network. The concepts 115 of MPLS-Context-tables and upstream allocation are described in 116 [RFC5331]. 118 BGP speakers participating in the private MPLS FIB layer create 119 instances of "MPLS forwarding-context" FIBs, which are identified 120 using a "Context-Protocol-Nexthop (CPNH)". A Context-label MAY be 121 advertised in conjunction with the Context Protocol Nexthop (CPNH) 122 using new BGP address-family to other speakers. 124 2. Motivation 126 A provider's core network consists of a global-domain (default 127 forwarding-tables in P and PE nodes) that is shared by all tenants in 128 the network and may also contain multiple private user-domains (e.g. 129 VRF route tables). 131 The global MPLS forwarding-layer can be viewed as the collection of 132 all default MPLS forwarding-tables. This global MPLS Fib layer 133 contains labels locally significant to each node. The "local- 134 significance of labels" gives the nodes freedom to participate in 135 MPLS-forwarding with whatever label-ranges they can support in 136 forwarding hardware. 138 In emerging usecases some applications using the MPLS-network may 139 benefit from a "static labels" view of the MPLS-network. In some 140 other usecases, a standard mechanism to do Upstream label-allocation 141 is beneficial. 143 It is desirable to leave the global MPLS FIB layer intact, and build 144 private MPLS FIB-layers on top of it to achieve these requirements. 146 The private-MPLS-FIBs can then be used by the applications as 147 desired. The private MPLS-FIBs need to be created only at the nodes 148 in the network where predictable label-values (external label 149 allocation) is desired. E.g. P-routers that need to act as a 150 "Detour-nodes" or "Service-Forwarding-Helpers" that need to mirror 151 service-labels. 153 In other words, provisioning of these private MPLS-FIBs can be 154 gradual and can co-exist with nodes not supporting the feature 155 described in this document. These private-MPLS-FIBs can be stitched 156 together using either the Context-labels over the existing shared 157 MPLS-network tunnels, or 'private' context-interfaces - to form the 158 "private MPLS-FIB layer". 160 An application can then install the routes with desired label-values 161 in the private forwarding-contexts with desired forwarding-semantics. 163 3. Constructs and building blocks 165 The building-blocks that construct a private MPLS plane are described 166 in this section. 168 3.1. Context Protocol Nexthop Address 170 A private MPLS plane (just "MPLS plane" here-after) is identified by 171 an IP-address called Context Protocol Nexthop (CPNH). This address 172 is unique in the core-network, like any other loopback address. 174 A loopback-address uniquely identifies a specific node in the 175 network, and we call it Global Protocol Nexthop (GPNH) in this 176 document. The CPNH address uniquely identifies a "MPLS-plane". 178 Each node that has forwarding-context for a MPLS-plane MUST be 179 configured with the same CPNH but a different RD, such that the 180 RD:CPNH will uniquely identify that node in the MPLS-plane. 182 3.2. MPLS context FIB 184 An instance of a MPLS forwarding-table at a node in the private MPLS- 185 plane. This Private MPLS FIB contains the private-label routes. 187 A node can have context-FIB for multiple MPLS-planes. The same 188 label-value can have a different forwarding-semantic in each MPLS- 189 plane. Thus the applications using that MPLS-plane get a 190 deterministic label-value independent of other applications using 191 other MPLS-planes. 193 The terms "private MPLS FIB-layer" and "private MPLS-plane" are used 194 interchangeably in this document. 196 3.3. Context Label 198 A context-label is a non-reserved dynamically allocated label, that 199 is installed in the global MPLS FIB, and points to a MPLS-Context- 200 FIB. The Context-Label have forwarding semantics as follows in the 201 global MPLS-FIB: 203 Context-Label -> Pop and Lookup in MPLS-Context-Fib 205 Advertising the "Context-Label in conjunction with the GPNH" tells 206 the network how to reach a "RD:CPNH". 208 3.4. Roles of nodes in a MPLS-plane 210 The node roles in a MPLS-plane can be classified into "edge nodes" 211 (call them PLER) or "transit-nodes" (call them PLSR). 213 3.4.1. Edge-nodes (PLER) 215 Private Label Edge-routers (PLER) have MPLS context-FIB that belong 216 to the MPLS-plane. They advertise the presence of this context-FIB, 217 and private-label routes from this FIB, using new BGP AFI/SAFI 218 described in this document. 220 3.4.2. Transit-nodes (PLSR) 222 Private Label Transit-nodes do label-swap forwarding for the Context- 223 Labels they see in the Context-Protocol-Nexthop advertisement routes 224 going thru them. They basically stitch/extend the label switched 225 path to a RD:CPNH when they re-advertise the CPNH routes with 226 nexthop-self. 228 PLSRs dont have context-FIBs. PLSRs dont have Context Protocol- 229 Nexthop. Because they dont have Private label routes to originate. 231 However a node in the network can play both roles, of PLER and PLSR. 233 3.5. Sending traffic into the MPLS plane 235 MPLS-traffic arriving with private-labels hits the correct private 236 MPLS-FIB by virtue of either arriving on a "private network- 237 interface" that is attached to the FIB, or arriving on a shared 238 network-interface with a "Context-label". 240 To send data traffic into this private MPLS FIB-layer, the 241 application MUST use as handle either a "Context-label" advertised by 242 a node or a "Private-interface" owned by the application at the node. 244 The Context-Label is the only label-value the application needs to 245 learn from the network (PLER node it is connected to), to be able to 246 use the private MPLS-plane. The application can decide the value of 247 the labels to be programmed in the private MPLS-FIBs. 249 Once the packet enters the private MPLS plane at an edge-node (PLER), 250 the node will forward the packet to the next node (PLSR or PLER), by 251 pushing the Context-label advertised by that next-node, and the 252 transport-label to reach that node's GPNH. This will repeat until 253 the packet reaches the private MPLS-FIB that originated that private 254 MPLS-label. 256 At each PLER in the MPLS-plane, the private-label value remains the 257 same, and points towards the same resource attached to the MPLS- 258 plane. This allows the applications using the MPLS-network a static- 259 labels view of the resourses attached to the private MPLS-plane. 261 At each PLSR in the MPLS-plane, the context-label value will change 262 (be swapped in forwarding), but is transparent to the application. 264 4. Terminology 266 P-router : A Provider core router, also called a LSR 268 LSR : Label Switch Router (pure transport node speaking LDP, RSVP 269 etc) 271 PLSR: a transit node in a private MPLS-plane. It has a forwarding- 272 context for private-labels. 274 PLER: an edge node in a private MPLS-plane. It has a forwarding- 275 context for private-labels. 277 Detour-router : A P-router that is used as a loose-hop in a traffic- 278 engineered path 280 PE-router : Provider Edge router, that hosts a service (Internet, 281 L3VPN etc) 283 SE-router : Service Edge router. Same as PE. 285 SFH-router : Service Forwarding Helper. A node helping an SE-router 286 with service-traffic forwarding, using Service-routes mirrored by the 287 SE. 289 MPLS FIB : MPLS Forwarding table 291 Global MPLS FIB : Global MPLS Forwarding table, to which shared- 292 interfaces are connected 294 Private MPLS FIB : Private MPLS Forwarding table, to which private- 295 interfaces are connected 297 Private MPLS FIB Layer : The group of Private MPLS FIBs in the 298 network, connected together via Context-Labels 300 Context-Label : Locally-significant Non-reserved label pointing to a 301 private MPLS FIB 303 Context nexthop IP-address (CPNH) : An IP-address that identifies the 304 "Private MPLS FIB Layer". RD:CPNH identifies a Private MPLS FIB at a 305 node. 307 Global nexthop IP-address (GPNH) : Global Protocol Nexthop address. 308 E.g. a loopback address used as transport tunnel end-point. 310 5. BGP families, routes and encoding 312 This section describes the new constructs defined by this document. 314 5.1. New address-families 316 This document defines a new AFI: "MPLS". And two new address- 317 families. 319 5.1.1. AFI: MPLS, SAFI: 128 321 This address-family is used to exchange private label-routes into 322 private MPLS-FIBs at routers that are connected using a common 323 network-interface. 325 Routes in this family contain Route-Target extended-community 326 identifying the private-FIB-Layer (VPN) the route belongs to. This 327 address-family also advertises the Context-Label that the receiving 328 router uses to access the private MPLS-FIB. The Context-Label is 329 required when the connecting-interface is a shared common interface 330 that terminates into the global MPLS FIB. The Context-Label 331 installed in the global MPLS-FIB points to the private MPLS-FIB. 333 Routes of this address-family can be sent with either IPv4 or IPv6 334 nexthop. The type of nexthop is inferred from the length of the 335 nexthop. 337 When the length of Next Hop Address field is 24 (or 48) the nexthop 338 address is of type VPN-IPv6 with 8-octet RD set to zero (potentially 339 followed by the link-local VPN-IPv6 address of the next hop with an 340 8-octet RD set to zero). 342 When the length of Next Hop Address field is 12 the nexthop address 343 is of type VPN-IPv4 with 8-octet RD set to zero. 345 5.1.2. AFI: MPLS, SAFI: 1 347 This address-family is used to exchange private label-routes in 348 private MPLS-FIBs to routers that are connected using a private 349 network-interface. 351 Because the interface is private, and terminates directly into the 352 private MPLS-FIB, a Context-Label is not required to access the 353 private MPLS-FIB. 355 Routes of this address-family can be sent with either IPv4 or IPv6 356 nexthop. The type of nexthop is inferred from the length of the 357 nexthop. 359 When the length of Next Hop Address field is 16 (or 32) the nexthop 360 address is of type IPv6 (potentially followed by the link-local IPv6 361 address of the next hop). 363 When the length of Next Hop Address field is 4 the nexthop address is 364 a 4 octet IPv4 address. 366 5.2. Routes and Operational procedures 368 5.2.1. "Context-Nexthop" discovery route 370 The Context-NH discovery route is a [BGP-CT] family route that 371 carries CPNH in the "Prefix" portion of the NLRI. And the Context- 372 Label is carried in the "Label" field in the [RFC8277] format NLRI. 374 This route is advertised with the following path-attributes: 376 o BGP Nexthop attribute (code 14, MP_REACH) carrying GPNH address. 378 o Route-Target extended community, identifying the private FIB-layer 380 The "Context-Nexthop discovery route" is originated by each speaker 381 who acts as a PLER. The "RD:Context-nexthop" uniquely identifies the 382 private-FIB at the speaker. The "Context-nexthop address" uniquely 383 identifies the private-FIB-layer. 385 A speaker readvertising a Context-Nexthop discovery-route MUST follow 386 the mechanisms described in [BGP-CT]. Specifically when re- 387 advertising with "next-hop self" MUST allocate a new Label with a 388 forwarding semantic of "Swap Received-Context-Label, Forward to 389 Received-GPNH". This extends reachability to the CPNH across tunnel 390 domains. 392 5.2.2. "Private Label" routes 394 The Private Label routes are carried in the new address-family "MPLS 395 VpnUnicast" defined in this document. 397 NLRI Label Prefix (Private Label route) 399 +--------------------------------------------+ 400 | Route Distinguisher (RD) (8 octets) | 401 +--------------------------------------------+ 402 | 3107 Private Label value | 403 +--------------------------------------------+ 405 Private-Label-Value: The (upstream assigned) label value 407 Attributes on this route: 409 o BGP Nexthop attribute (code 14, MP_REACH) carrying a GPNH address. 410 (OR) 412 o The Multi-nexthop attribute [MULTI-NH] with forwarding-semantic: 414 * "Forward to RD:CPNH" 416 o Route-Target extended-community, identifying the private FIB-layer 418 MultiNexthop BGP-attribute (Private Label route) 420 +--------------------------------------------+ 421 | MultiNH.Num-Nexthops = 1 | 422 +--------------------------------------------+ 423 | FwdSemanticsTLV.FwdAction = Forward | 424 +--------------------------------------------+ 425 | NHDescrTLV.NhopDescrType = RD:CPNH or GPNH| 426 +--------------------------------------------+ 428 A speaker MAY readvertise a private-label-route without changing the 429 Nexthop (RD:CPNH) carried in it, if the speaker is a pure PLSR. 431 If it does alter the nexthop to SelfRD:CPNH, it SHOULD act as a PLER, 432 and for e.g. originate a "Context-Nexthop discovery route" for prefix 433 "SelfRD:CPNH". 435 Even if the speaker sets nexthop-address to Self because of regular 436 BGP readvertisement-rules, Label Prefix MUST NOT be altered, and the 437 received NLRI "RD:Private-Label1" MUST be re-advertised as-is. Such 438 that value of label "Private-Label1" doesn't change while the packet 439 traverses multiple nodes in the private-MPLS-FIB-layer. 441 The Route-target attached to the route is the one identifying the 442 private MPLS FIB layer (VPN). The Private-label routes resolve over 443 the Context-nexthop route that belong to the same VPN. 445 A node receiving a "Private-Label route" RD:L1 MUST install the label 446 L1 in the private MPLS Forwarding-context idenfied by the Route- 447 Target attached to the route. 449 The label route MUST be installed with forwarding-semantic as 450 specified in the received Multi-nexthop attribute. As an example, a 451 Detour node MAY receive the private-label-route with a forwarding- 452 semantic of "Forward to RD:CPNH" operation. And an Egress node MAY 453 receive a private-label-route with a forwarding-semantic pointing to 454 a resource it houses. Note that such a Private-label BGP-route MAY 455 be received from external-application also. 457 5.2.2.1. Resolving received Private Label-routes 459 A node receiving a "Context-nexthop discovery route" MUST be capable 460 of using either the CPNH or the RD:CPNH carried in the NLRI, to 461 resolve other routes received with this CPNH address or RD:CPNH in 462 the "Nexthop-attributes". 464 The receiver of a private-label route MUST recursively resolve the 465 received nexthop (RD:CPNH) over the Context-Nexthop discovery-route 466 for prefix "RD:CPNH" to determine the label stack "Context-Label, 467 Transport-Label" to push, so that the MPLS packet with private-label 468 reaches the private MPLS FIB originating the route. 470 If a node receives multiple "Context-nexthop discovery route" for a 471 CPNH, it SHOULD run path-selection after stripping the RD, to find 472 the closest ingress to the private-MPLS-plane identified by the CPNH. 473 This best path SHOULD be used to resolve a received private-label- 474 route. 476 6. Example of Usecases 478 6.1. Mezanine transport layer in a Seamless-MPLS network 480 Typically service-routes in a MPLS network bind to the following 481 entities that identify point-of-presence of a service: 483 o Protocol Nexthop - PE loopback address (GPNH) 485 o Service Label - PE advertised locally signifcant label that 486 identifies the service 488 In this model, whenever a PE is taken out of service the GPNH 489 changes, and Service-Label changes - which causes maintenance a heavy 490 convergence event. Because the service-routes with massive-scale 491 need to be readvertised with new service-label or PE-address. 493 An alternate model could be: to advertise the Service-routes with a 494 protocol-nexthop of CPNH (without RD), with a forwarding-semantic of: 496 o "Push , and Forward to CPNH" 498 This model fully decouples the service-layer from the transport-layer 499 identifiers, by making the Service-routes refer to the CPNH and 500 Private-Labels. Thus the underlying transport-layer can change 501 (nodes representing a Private-label can be added or removed) without 502 any changes to the service-routes. Which present good scaling 503 properties for the network. 505 This model also allows anycast traffic forwarding to any resource in 506 the network. Multiple PEs can advertise the same Private-Label to 507 identify a specific service (e.g. peering with an AS) they are 508 offering. 510 Once the service-route traffic enters the private-FIB-layer, at the 511 closest entry-point determined by path-selection of CPNH auto- 512 discovery routes; then the Private-Labels (with pre-determined 513 values) pushed will determine the loose hop path taken by the traffic 514 and also the destination-resource. 516 6.2. Service Forwarding Helper usecase 518 In a virtualized environment a Service-PE node (that comprises of a 519 vCP and multiple vFPs) can mirror MPLS labels (GL1) in its global 520 MPLS-FIB to a private forwarding context at an upstream node (SFH) 521 with information on which vFPs are optimal exit-points for that 522 label. Such that the SFH can optimally forward traffic to GL1 to the 523 right vFPs, thus avoiding intra fabric traffic hops. 525 To do this, the service-PE advertises a private-label route with 526 RD:GL1 to the SFH node. The route is advertised with a Multi-nexthop 527 attribute with one or more legs that have a "Forward to SEPx" 528 semantics. Where SEPx is one of many exit-points at the Service-PE 529 node. 531 6.3. Standard BGP API to a MPLS network's forwarding-plane 533 This mechanism facilitates predictable (external-allocator 534 determined) label-values, using a standard BGP-family as the API. It 535 gives the external applications a separate MPLS-FIB to play with, 536 totally separate from other applications. 538 This also avoids vendor specific-API dependencies for external- 539 allocators (controller softwares), and vice-versa. 541 This mechanism also increases the overal MPLS label-space available 542 in the network, because it creates per-app label-forwarding-contexts 543 (namespaces), instead of reserving/splitting the global MPLS FIB 544 among various applications. 546 6.4. Traffic engineering and Security advantages 548 o Ability of ingress to steer mpls-traffic thru specific detour 549 loose-hop nodes using predictable-labels' stack. 551 o Provide label-spoofing protection at edge-nodes - by virtue of 552 using separate mpls-forwarding-contexts 554 o Allow private-MPLS label usage to spread across multiple-domains/ 555 AS and work seamlessly with existing technologies like Inter-AS 556 VPN option C. 558 7. IANA Considerations 560 This document makes following requests of IANA. 562 New BGP AFI code: 564 o for "MPLS" 566 Which will be used to create new BGP AFI-SAFI pairs: 568 o MPLS Uni(SAFI:1), 570 o MPLS VpnUni(SAFI:128) 572 . 574 New NLRI Route-types for these AFI SAFIs: 576 o Type 1: Context-Nexthop-Discovery-route. 578 o Type 2: Private-Label route 580 Note to RFC Editor: this section may be removed on publication as an 581 RFC. 583 8. Security Considerations 585 Using separate mpls-forwarding-contexts for separate applications and 586 stitching them into separate MPLS-planes increases the security 587 attributes of the MPLS network. 589 9. Acknowledgements 591 The authors thank Jeffrey (Zhaohui) Zhang, Ron Bonica, Jeff Haas and 592 John Scudder for the valuable discussions. 594 10. Normative References 596 [BGP-CT] Vairavakkalai, K., "BGP Classful Transport Planes", June 597 2021, . 600 [MULTI-NH] 601 Vairavakkalai, K., "BGP MultiNexthop attribute", June 602 2021, . 605 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 606 Requirement Levels", BCP 14, RFC 2119, 607 DOI 10.17487/RFC2119, March 1997, 608 . 610 [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private 611 Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 612 2006, . 614 [RFC5331] Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream 615 Label Assignment and Context-Specific Label Space", 616 RFC 5331, DOI 10.17487/RFC5331, August 2008, 617 . 619 [RFC8277] Rosen, E., "Using BGP to Bind MPLS Labels to Address 620 Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017, 621 . 623 Authors' Addresses 625 Kaliraj Vairavakkalai 626 Juniper Networks, Inc. 627 1133 Innovation Way, 628 Sunnyvale, CA 94089 629 US 631 Email: kaliraj@juniper.net 633 Minto Jeyananth 634 Juniper Networks, Inc. 635 1133 Innovation Way, 636 Sunnyvale, CA 94089 637 US 639 Email: minto@juniper.net