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The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (September 28, 2017) is 2401 days in the past. Is this intentional? Checking references for intended status: Best Current Practice ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Downref: Normative reference to an Informational RFC: RFC 4609 -- Possible downref: Non-RFC (?) normative reference: ref. 'BCP38' -- Possible downref: Non-RFC (?) normative reference: ref. 'BCP41' == Outdated reference: A later version (-05) exists of draft-ietf-mboned-mdh-04 Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 MBONED Working Group Percy S. Tarapore 2 Internet Draft Robert Sayko 3 Intended status: BCP AT&T 4 Expires: March 28, 2018 Greg Shepherd 5 Cisco 6 Toerless Eckert 7 Futurewei Technologies 8 Ram Krishnan 9 SupportVectors 10 September 28, 2017 12 Use of Multicast Across Inter-Domain Peering Points 13 draft-ietf-mboned-interdomain-peering-bcp-11.txt 15 Status of this Memo 17 This Internet-Draft is submitted in full conformance with the 18 provisions of BCP 78 and BCP 79. 20 Internet-Drafts are working documents of the Internet Engineering 21 Task Force (IETF). Note that other groups may also distribute 22 working documents as Internet-Drafts. The list of current Internet- 23 Drafts is at http://datatracker.ietf.org/drafts/current/. 25 Internet-Drafts are draft documents valid for a maximum of six 26 months and may be updated, replaced, or obsoleted by other documents 27 at any time. It is inappropriate to use Internet-Drafts as 28 reference material or to cite them other than as "work in progress." 30 This Internet-Draft will expire on March 28, 2018. 32 Copyright Notice 34 Copyright (c) 2017 IETF Trust and the persons identified as the 35 document authors. All rights reserved. 37 This document is subject to BCP 78 and the IETF Trust's Legal 38 Provisions Relating to IETF Documents 39 (http://trustee.ietf.org/license-info) in effect on the date of 40 publication of this document. Please review these documents 41 carefully, as they describe your rights and restrictions with 42 respect to this document. Code Components extracted from this 43 document must include Simplified BSD License text as described in 44 Section 4.e of the Trust Legal Provisions and are provided without 45 warranty as described in the Simplified BSD License. 47 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 49 This document may contain material from IETF Documents or IETF 50 Contributions published or made publicly available before November 51 10, 2008. The person(s) controlling the copyright in some of this 52 material may not have granted the IETF Trust the right to allow 53 modifications of such material outside the IETF Standards Process. 54 Without obtaining an adequate license from the person(s) controlling 55 the copyright in such materials, this document may not be modified 56 outside the IETF Standards Process, and derivative works of it may 57 not be created outside the IETF Standards Process, except to format 58 it for publication as an RFC or to translate it into languages other 59 than English. 61 Abstract 63 This document examines the use of Source Specific Multicast (SSM) 64 across inter-domain peering points for a specified set of deployment 65 scenarios. The objective is to describe the setup process for 66 multicast-based delivery across administrative domains for these 67 scenarios and document supporting functionality to enable this 68 process. 70 Table of Contents 72 1. Introduction .................................................. 3 73 2. Overview of Inter-domain Multicast Application Transport ...... 5 74 3. Inter-domain Peering Point Requirements for Multicast ......... 6 75 3.1. Native Multicast ......................................... 6 76 3.2. Peering Point Enabled with GRE Tunnel .................... 8 77 3.3. Peering Point Enabled with an AMT - Both Domains Multicast 78 Enabled ....................................................... 9 79 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast 80 Enabled ...................................................... 11 81 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through 82 AD-2 ......................................................... 13 83 4. Functional Guidelines ........................................ 15 84 4.1. Network Interconnection Transport and Security Guidelines15 85 4.2. Routing Aspects and Related Guidelines .................. 16 86 4.2.1 Native Multicast Routing Aspects ................. 16 87 4.2.2 GRE Tunnel over Interconnecting Peering Point .... 17 88 4.2.3 Routing Aspects with AMT Tunnels ................. 17 89 4.3. Back Office Functions - Provisioning and Logging Guidelines 90 ............................................................. 20 91 4.3.1 Provisioning Guidelines .......................... 20 92 4.3.2 Application Accounting Guidelines ................ 22 93 4.3.3 Log Management Guidelines ........................ 22 94 4.4. Operations - Service Performance and Monitoring Guidelines23 96 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 98 4.5. Client Reliability Models/Service Assurance Guidelines .. 25 99 5. Troubleshooting and Diagnostics .............................. 25 100 6. Security Considerations ...................................... 26 101 7. IANA Considerations .......................................... 27 102 8. Conclusions .................................................. 27 103 9. References ................................................... 28 104 9.1. Normative References .................................... 28 105 9.2. Informative References .................................. 29 106 10. Acknowledgments ............................................. 29 108 1. Introduction 110 Content and data from several types of applications (e.g., live 111 video streaming, software downloads) are well suited for delivery 112 via multicast means. The use of multicast for delivering such 113 content/data offers significant savings of utilization of resources 114 in any given administrative domain. End user demand for such 115 content/data is growing. Often, this requires transporting the 116 content/data across administrative domains via inter-domain peering 117 points. 119 The objective of this Best Current Practices document is twofold: 120 o Describe the technical process and establish guidelines for 121 setting up multicast-based delivery of application content/data 122 across inter-domain peering points via a set of use cases. 123 o Catalog all required information exchange between the 124 administrative domains to support multicast-based delivery. 125 This enables operators to initiate necessary processes to 126 support inter-domain peering with multicast. 128 The scope and assumptions for this document are stated as follows: 130 o For the purpose of this document, the term "peering point" 131 refers to an interface between two networks/administrative 132 domains over which traffic is exchanged between them. A 133 Network-Network Interface (NNI) is an example of a peering 134 point. 135 o Administrative Domain 1 (AD-1) is enabled with native 136 multicast. A peering point exists between AD-1 and AD-2. 137 o It is understood that several protocols are available for this 138 purpose including PIM-SM and Protocol Independent Multicast - 139 Source Specific Multicast (PIM-SSM) [RFC7761], Internet Group 140 Management Protocol (IGMP) [RFC3376], and Multicast Listener 141 Discovery (MLD) [RFC3810]. 143 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 145 o As described in Section 2, the source IP address of the 146 multicast stream in the originating AD (AD-1) is known. Under 147 this condition, PIM-SSM use is beneficial as it allows the 148 receiver's upstream router to directly send a JOIN message to 149 the source without the need of invoking an intermediate 150 Rendezvous Point (RP). Use of SSM also presents an improved 151 threat mitigation profile against attack, as described in 152 [RFC4609]. Hence, in the case of inter-domain peering, it is 153 recommended to use only SSM protocols; the setup of inter- 154 domain peering for ASM (Any-Source Multicast) is not in scope 155 for this document. 156 o AD-1 and AD-2 are assumed to adopt compatible protocols. The 157 use of different protocols is beyond the scope of this 158 document. 159 o An Automatic Multicast Tunnel (AMT) [RFC7450] is setup at the 160 peering point if either the peering point or AD-2 is not 161 multicast enabled. It is assumed that an AMT Relay will be 162 available to a client for multicast delivery. The selection of 163 an optimal AMT relay by a client is out of scope for this 164 document. Note that AMT use is necessary only when native 165 multicast is unavailable in the peering point (Use Case 3.3) or 166 in the downstream administrative domain (Use Cases 3.4, and 167 3.5). 168 o The collection of billing data is assumed to be done at the 169 application level and is not considered to be a networking 170 issue. The settlements process for end user billing and/or 171 inter-provider billing is out of scope for this document. 172 o Inter-domain network connectivity troubleshooting is only 173 considered within the context of a cooperative process between 174 the two domains. 175 Thus, the primary purpose of this document is to describe a scenario 176 where two AD's interconnect via a a peering point with each other. 177 Security and operational aspects for exchanging traffic on a public 178 Internet Exchange Point (IXP) with a large shared broadcast domain 179 between many operators, is not in scope for this document. 181 It may be possible to have a configuration whereby a transit domain 182 (AD-3) interconnects AD-1 and AD-2. Such a configuration adds 183 complexity and may require manual provisioning if, for example, AD-3 184 is not multicast enabled. This configuration is out of cope for this 185 document; it is for further study. 187 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 189 This document also attempts to identify ways by which the peering 190 process can be improved. Development of new methods for improvement 191 is beyond the scope of this document. 193 2. Overview of Inter-domain Multicast Application Transport 195 A multicast-based application delivery scenario is as follows: 196 o Two independent administrative domains are interconnected via a 197 peering point. 198 o The peering point is either multicast enabled (end-to-end 199 native multicast across the two domains) or it is connected by 200 one of two possible tunnel types: 201 o A Generic Routing Encapsulation (GRE) Tunnel [RFC2784] 202 allowing multicast tunneling across the peering point, or 203 o An Automatic Multicast Tunnel (AMT) [RFC7450]. 204 o A service provider controls one or more application sources in 205 AD-1 which will send multicast IP packets for one or more 206 (S,G)s. It is assumed that the service being provided is 207 suitable for delivery via multicast (e.g. live video streaming 208 of popular events, software downloads to many devices, etc.), 209 and that the packet streams will be part of a suitable 210 multicast transport protocol. 211 o An End User (EU) controls a device connected to AD-2, which 212 runs an application client compatible with the service 213 provider's application source. 214 o The application client joins appropriate (S,G)s in order to 215 receive the data necessary to provide the service to the EU. 216 The mechanisms by which the application client learns the 217 appropriate (S,G)s are an implementation detail of the 218 application, and are out of scope for this document. 220 The assumption here is that AD-1 has ultimate responsibility for 221 delivering the multicast based service on behalf of the content 222 source(s). All relevant interactions between the two domains 223 described in this document are based on this assumption. 225 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 227 Note that domain 2 may be an independent network domain (e.g., Tier 228 1 network operator domain). Alternately, domain 2 could also be an 229 Enterprise network domain operated by a single customer. The peering 230 point architecture and requirements may have some unique aspects 231 associated with the Enterprise case. 233 The Use Cases describing various architectural configurations for 234 the multicast distribution along with associated requirements is 235 described in section 3. Unique aspects related to the Enterprise 236 network possibility will be described in this section. Section 4 237 contains a comprehensive list of pertinent information that needs to 238 be exchanged between the two domains in order to support functions 239 to enable the application transport. 241 3. Inter-domain Peering Point Requirements for Multicast 243 The transport of applications using multicast requires that the 244 inter-domain peering point is enabled to support such a process. 245 There are five Use Cases for consideration in this document. 247 3.1. Native Multicast 249 This Use Case involves end-to-end Native Multicast between the two 250 administrative domains and the peering point is also native 251 multicast enabled - Figure 1. 253 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 255 ------------------- ------------------- 256 / AD-1 \ / AD-2 \ 257 / (Multicast Enabled) \ / (Multicast Enabled) \ 258 / \ / \ 259 | +----+ | | | 260 | | | +------+ | | +------+ | +----+ 261 | | AS |------>| BR |-|---------|->| BR |-------------|-->| EU | 262 | | | +------+ | I1 | +------+ |I2 +----+ 263 \ +----+ / \ / 264 \ / \ / 265 \ / \ / 266 ------------------- ------------------- 268 AD = Administrative Domain (Independent Autonomous System) 269 AS = Application (e.g., Content) Multicast Source 270 BR = Border Router 271 I1 = AD-1 and AD-2 Multicast Interconnection (e.g., MBGP) 272 I2 = AD-2 and EU Multicast Connection 274 Figure 1 - Content Distribution via End to End Native Multicast 276 Advantages of this configuration are: 278 o Most efficient use of bandwidth in both domains. 280 o Fewer devices in the path traversed by the multicast stream when 281 compared to an AMT enabled peering point. 283 From the perspective of AD-1, the one disadvantage associated with 284 native multicast into AD-2 instead of individual unicast to every EU 285 in AD-2 is that it does not have the ability to count the number of 286 End Users as well as the transmitted bytes delivered to them. This 287 information is relevant from the perspective of customer billing and 288 operational logs. It is assumed that such data will be collected by 289 the application layer. The application layer mechanisms for 290 generating this information need to be robust enough such that all 291 pertinent requirements for the source provider and the AD operator 292 are satisfactorily met. The specifics of these methods are beyond 293 the scope of this document. 295 Architectural guidelines for this configuration are as follows: 297 a. Dual homing for peering points between domains is recommended 298 as a way to ensure reliability with full BGP table visibility. 300 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 302 b. If the peering point between AD-1 and AD-2 is a controlled 303 network environment, then bandwidth can be allocated 304 accordingly by the two domains to permit the transit of non- 305 rate adaptive multicast traffic. If this is not the case, then 306 it is recommended that the multicast traffic should support 307 rate-adaption. 309 c. The sending and receiving of multicast traffic between two 310 domains is typically determined by local policies associated 311 with each domain. For example, if AD-1 is a service provider 312 and AD-2 is an enterprise, then AD-1 may support local policies 313 for traffic delivery to, but not traffic reception from, AD-2. 314 Another example is the use of a policy by which AD-1 delivers 315 specified content to AD-2 only if such delivery has been 316 accepted by contract. 318 d. Relevant information on multicast streams delivered to End 319 Users in AD-2 is assumed to be collected by available 320 capabilities in the application layer. The precise nature and 321 formats of the collected information will be determined by 322 directives from the source owner and the domain operators. 324 e. The interconnection of AD-1 and AD-2 should, at a minimum, 325 follow guidelines for traffic filtering between autonomous 326 systems [BCP38]. Filtering guidelines specific to the multicast 327 control-plane and data-plane are described in section 6. 329 3.2. Peering Point Enabled with GRE Tunnel 331 The peering point is not native multicast enabled in this Use Case. 332 There is a Generic Routing Encapsulation Tunnel provisioned over the 333 peering point. In this case, the interconnection I1 between AD-1 and 334 AD-2 in Figure 1 is multicast enabled via a Generic Routing 335 Encapsulation Tunnel (GRE) [RFC2784] and encapsulating the multicast 336 protocols across the interface. The routing configuration is 337 basically unchanged: Instead of BGP (SAFI2) across the native IP 338 multicast link between AD-1 and AD-2, BGP (SAFI2) is now run across 339 the GRE tunnel. 341 Advantages of this configuration: 343 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 345 o Highly efficient use of bandwidth in both domains, although not 346 as efficient as the fully native multicast Use Case. 348 o Fewer devices in the path traversed by the multicast stream 349 when compared to an AMT enabled peering point. 351 o Ability to support only partial IP multicast deployments in AD- 352 1 and/or AD-2 (the two Border Routers in Figure 1 do not need 353 to be the two "unicast" domain border routers; instead they can 354 be anywhere in AD-1 and AD-2). 356 o GRE is an existing technology and is relatively simple to 357 implement. 359 Disadvantages of this configuration: 361 o Per Use Case 3.1, current router technology cannot count the 362 number of end users or the number bytes transmitted. 364 o GRE tunnel requires manual configuration. 366 o The GRE must be established prior to stream starting. 368 o The GRE tunnel is often left pinned up. 370 Architectural guidelines for this configuration include the 371 following: 373 Guidelines (a) through (d) are the same as those described in Use 374 Case 3.1. Two additional guidelines are as follows: 376 e. GRE tunnels are typically configured manually between peering 377 points to support multicast delivery between domains. 379 f. It is recommended that the GRE tunnel (tunnel server) 380 configuration in the source network is such that it only 381 advertises the routes to the application sources and not to the 382 entire network. This practice will prevent unauthorized delivery 383 of applications through the tunnel (e.g., if application - e.g., 384 content - is not part of an agreed inter-domain partnership). 386 3.3. Peering Point Enabled with an AMT - Both Domains Multicast 387 Enabled 389 Both administrative domains in this Use Case are assumed to be 390 native multicast enabled here; however, the peering point is not. 392 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 394 The peering point is enabled with an Automatic Multicast Tunnel. The 395 basic configuration is depicted in Figure 2. 397 ------------------- ------------------- 398 / AD-1 \ / AD-2 \ 399 / (Multicast Enabled) \ / (Multicast Enabled) \ 400 / \ / \ 401 | +----+ | | | 402 | | | +------+ | | +------+ | +----+ 403 | | AS |------>| AR |-|---------|->| AG |-------------|-->| EU | 404 | | | +------+ | I1 | +------+ |I2 +----+ 405 \ +----+ / \ / 406 \ / \ / 407 \ / \ / 408 ------------------- ------------------- 410 AR = AMT Relay 411 AG = AMT Gateway 412 I1 = AMT Interconnection between AD-1 and AD-2 413 I2 = AD-2 and EU Multicast Connection 415 Figure 2 - AMT Interconnection between AD-1 and AD-2 417 Advantages of this configuration: 419 o Highly efficient use of bandwidth in AD-1. 421 o AMT is an existing technology and is relatively simple to 422 implement. Attractive properties of AMT include the following: 424 o Dynamic interconnection between Gateway-Relay pair across 425 the peering point. 427 o Ability to serve clients and servers with differing 428 policies. 430 Disadvantages of this configuration: 432 o Per Use Case 3.1 (AD-2 is native multicast), current router 433 technology cannot count the number of end users or the number 434 of bytes transmitted to all end users. 436 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 438 o Additional devices (AMT Gateway and Relay pairs) may be 439 introduced into the path if these services are not incorporated 440 in the existing routing nodes. 442 o Currently undefined mechanisms for the AG to automatically 443 select the optimal AR. 445 Architectural guidelines for this configuration are as follows: 447 Guidelines (a) through (d) are the same as those described in Use 448 Case 3.1. In addition, 450 e. It is recommended that AMT Relay and Gateway pairs be 451 configured at the peering points to support multicast delivery 452 between domains. AMT tunnels will then configure dynamically 453 across the peering points once the Gateway in AD-2 receives the 454 (S, G) information from the EU. 456 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast Enabled 458 In this AMT Use Case, the second administrative domain AD-2 is not 459 multicast enabled. Hence, the interconnection between AD-2 and the 460 End User is also not multicast enabled. This Use Case is depicted in 461 Figure 3. 463 ------------------- ------------------- 464 / AD-1 \ / AD-2 \ 465 / (Multicast Enabled) \ / (Non-Multicast \ 466 / \ / Enabled) \ 467 | +----+ | | | 468 | | | +------+ | | | +----+ 469 | | AS |------>| AR |-|---------|-----------------------|-->|EU/G| 470 | | | +------+ | | |I2 +----+ 471 \ +----+ / \ / 472 \ / \ / 473 \ / \ / 474 ------------------- ------------------- 476 AS = Application Multicast Source 477 AR = AMT Relay 478 EU/G = Gateway client embedded in EU device 479 I2 = AMT Tunnel Connecting EU/G to AR in AD-1 through Non-Multicast 480 Enabled AD-2. 482 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 484 Figure 3 - AMT Tunnel Connecting AD-1 AMT Relay and EU Gateway 486 This Use Case is equivalent to having unicast distribution of the 487 application through AD-2. The total number of AMT tunnels would be 488 equal to the total number of End Users requesting the application. 489 The peering point thus needs to accommodate the total number of AMT 490 tunnels between the two domains. Each AMT tunnel can provide the 491 data usage associated with each End User. 493 Advantages of this configuration: 495 o Highly efficient use of bandwidth in AD-1. 497 o AMT is an existing technology and is relatively simple to 498 implement. Attractive properties of AMT include the following: 500 o Dynamic interconnection between Gateway-Relay pair across 501 the peering point. 503 o Ability to serve clients and servers with differing 504 policies. 506 o Each AMT tunnel serves as a count for each End User and is also 507 able to track data usage (bytes) delivered to the EU. 509 Disadvantages of this configuration: 511 o Additional devices (AMT Gateway and Relay pairs) are introduced 512 into the transport path. 514 o Assuming multiple peering points between the domains, the EU 515 Gateway needs to be able to find the "correct" AMT Relay in AD- 516 1. 518 Architectural guidelines for this configuration are as follows: 520 Guidelines (a) through (c) are the same as those described in Use 521 Case 3.1. 523 d. It is recommended that proper procedures are implemented such 524 that the AMT Gateway at the End User device is able to find the 525 correct AMT Relay in AD-1 across the peering points. The 526 application client in the EU device is expected to supply the (S, 527 G) information to the Gateway for this purpose. 529 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 531 e. The AMT tunnel capabilities are expected to be sufficient for 532 the purpose of collecting relevant information on the multicast 533 streams delivered to End Users in AD-2. 535 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through AD-2 537 This is a variation of Use Case 3.4 as follows: 539 ------------------- ------------------- 540 / AD-1 \ / AD-2 \ 541 / (Multicast Enabled) \ / (Non-Multicast \ 542 / \ / Enabled) \ 543 | +----+ | |+--+ +--+ | 544 | | | +------+ | ||AG| |AG| | +----+ 545 | | AS |------>| AR |-|-------->||AR|------------->|AR|-|-->|EU/G| 546 | | | +------+ | I1 ||1 | I2 |2 | |I3 +----+ 547 \ +----+ / \+--+ +--+ / 548 \ / \ / 549 \ / \ / 550 ------------------- ------------------- 552 AS = Application Source 553 AR = AMT Relay in AD-1 554 AGAR1 = AMT Gateway/Relay node in AD-2 across Peering Point 555 I1 = AMT Tunnel Connecting AR in AD-1 to GW in AGAR1 in AD-2 556 AGAR2 = AMT Gateway/Relay node at AD-2 Network Edge 557 I2 = AMT Tunnel Connecting Relay in AGAR1 to GW in AGAR2 558 EU/G = Gateway client embedded in EU device 559 I3 = AMT Tunnel Connecting EU/G to AR in AGAR2 561 Figure 4 - AMT Tunnel Connecting AD-1 AMT Relay and EU Gateway 563 Use Case 3.4 results in several long AMT tunnels crossing the entire 564 network of AD-2 linking the EU device and the AMT Relay in AD-1 565 through the peering point. Depending on the number of End Users, 566 there is a likelihood of an unacceptably large number of AMT tunnels 567 - and unicast streams - through the peering point. This situation 568 can be alleviated as follows: 570 o Provisioning of strategically located AMT nodes at the edges of 571 AD-2. An AMT node comprises co-location of an AMT Gateway and 573 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 575 an AMT Relay. One such node is at the AD-2 side of the peering 576 point (node AGAR1 in Figure 4). 578 o Single AMT tunnel established across peering point linking AMT 579 Relay in AD-1 to the AMT Gateway in the AMT node AGAR1 in AD-2. 581 o AMT tunnels linking AMT node AGAR1 at peering point in AD-2 to 582 other AMT nodes located at the edges of AD-2: e.g., AMT tunnel 583 I2 linking AMT Relay in AGAR1 to AMT Gateway in AMT node AGAR2 584 in Figure 4. 586 o AMT tunnels linking EU device (via Gateway client embedded in 587 device) and AMT Relay in appropriate AMT node at edge of AD-2: 588 e.g., I3 linking EU Gateway in device to AMT Relay in AMT node 589 AGAR2. 591 The advantage for such a chained set of AMT tunnels is that the 592 total number of unicast streams across AD-2 is significantly 593 reduced, thus freeing up bandwidth. Additionally, there will be a 594 single unicast stream across the peering point instead of possibly, 595 an unacceptably large number of such streams per Use Case 3.4. 596 However, this implies that several AMT tunnels will need to be 597 dynamically configured by the various AMT Gateways based solely on 598 the (S,G) information received from the application client at the EU 599 device. A suitable mechanism for such dynamic configurations is 600 therefore critical. 602 Architectural guidelines for this configuration are as follows: 604 Guidelines (a) through (c) are the same as those described in Use 605 Case 3.1. 607 d. It is recommended that proper procedures are implemented such 608 that the various AMT Gateways (at the End User devices and the AMT 609 nodes in AD-2) are able to find the correct AMT Relay in other AMT 610 nodes as appropriate. The application client in the EU device is 611 expected to supply the (S, G) information to the Gateway for this 612 purpose. 614 e. The AMT tunnel capabilities are expected to be sufficient for 615 the purpose of collecting relevant information on the multicast 616 streams delivered to End Users in AD-2. 618 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 620 4. Functional Guidelines 622 Supporting functions and related interfaces over the peering point 623 that enable the multicast transport of the application are listed in 624 this section. Critical information parameters that need to be 625 exchanged in support of these functions are enumerated, along with 626 guidelines as appropriate. Specific interface functions for 627 consideration are as follows. 629 4.1. Network Interconnection Transport and Security Guidelines 631 The term "Network Interconnection Transport" refers to the 632 interconnection points between the two Administrative Domains. The 633 following is a representative set of attributes that will need to be 634 agreed to between the two administrative domains to support 635 multicast delivery. 637 o Number of Peering Points. 639 o Peering Point Addresses and Locations. 641 o Connection Type - Dedicated for Multicast delivery or shared 642 with other services. 644 o Connection Mode - Direct connectivity between the two AD's or 645 via another ISP. 647 o Peering Point Protocol Support - Multicast protocols that will 648 be used for multicast delivery will need to be supported at 649 these points. Examples of protocols include eBGP [RFC4760] and 650 MBGP [RFC4760]. 652 o Bandwidth Allocation - If shared with other services, then 653 there needs to be a determination of the share of bandwidth 654 reserved for multicast delivery. When determining the 655 appropriate bandwidth allocation, parties should consider use 656 of a multicast protocol suitable for live video streaming that 657 is consistent with Congestion Control Principles [BCP41]. 659 o QoS Requirements - Delay/latency specifications that need to be 660 specified in an SLA. 662 o AD Roles and Responsibilities - the role played by each AD for 663 provisioning and maintaining the set of peering points to 664 support multicast delivery. 666 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 668 4.2. Routing Aspects and Related Guidelines 670 The main objective for multicast delivery routing is to ensure that 671 the End User receives the multicast stream from the "most optimal" 672 source [INF_ATIS_10] which typically: 674 o Maximizes the multicast portion of the transport and minimizes 675 any unicast portion of the delivery, and 677 o Minimizes the overall combined network(s) route distance. 679 This routing objective applies to both Native and AMT; the actual 680 methodology of the solution will be different for each. Regardless, 681 the routing solution is expected: 683 o To be scalable, 685 o To avoid/minimize new protocol development or modifications, 686 and 688 o To be robust enough to achieve high reliability and 689 automatically adjust to changes/problems in the multicast 690 infrastructure. 692 For both Native and AMT environments, having a source as close as 693 possible to the EU network is most desirable; therefore, in some 694 cases, an AD may prefer to have multiple sources near different 695 peering points. However, that is entirely an implementation issue. 697 4.2.1 Native Multicast Routing Aspects 699 Native multicast simply requires that the Administrative Domains 700 coordinate and advertise the correct source address(es) at their 701 network interconnection peering points(i.e., border routers). An 702 example of multicast delivery via a Native Multicast process across 703 two Administrative Domains is as follows assuming that the 704 interconnecting peering points are also multicast enabled: 706 o Appropriate information is obtained by the EU client who is a 707 subscriber to AD-2 (see Use Case 3.1). This information is in 708 the form of metadata and it contains instructions directing the 709 EU client to launch an appropriate application if necessary, as 710 well as additional information for the application about the 711 source location and the group (or stream) id in the form of the 712 "S,G" data. The "S" portion provides the name or IP address of 713 the source of the multicast stream. The metadata may also 715 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 717 contain alternate delivery information such as specifying the 718 unicast address of the stream. 720 o The client uses the join message with S,G to join the multicast 721 stream [RFC4604]. 723 To facilitate this process, the two AD's need to do the following: 725 o Advertise the source id(s) over the Peering Points. 727 o Exchange relevant Peering Point information such as Capacity 728 and Utilization. 730 o Implement compatible multicast protocols to ensure proper 731 multicast delivery across the peering points. 733 4.2.2 GRE Tunnel over Interconnecting Peering Point 735 If the interconnecting peering point is not multicast enabled and 736 both AD's are multicast enabled, then a simple solution is to 737 provision a GRE tunnel between the two AD's - see Use Case 3.2.2. 738 The termination points of the tunnel will usually be a network 739 engineering decision, but generally will be between the border 740 routers or even between the AD 2 border router and the AD 1 source 741 (or source access router). The GRE tunnel would allow end-to-end 742 native multicast or AMT multicast to traverse the interface. 743 Coordination and advertisement of the source IP is still required. 745 The two AD's need to follow the same process as described in 4.2.1 746 to facilitate multicast delivery across the Peering Points. 748 4.2.3 Routing Aspects with AMT Tunnels 750 Unlike Native Multicast (with or without GRE), an AMT Multicast 751 environment is more complex. It presents a dual layered problem 752 because there are two criteria that should be simultaneously met: 754 o Find the closest AMT relay to the end-user that also has 755 multicast connectivity to the content source, and 757 o Minimize the AMT unicast tunnel distance. 759 There are essentially two components to the AMT specification: 761 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 763 o AMT Relays: These serve the purpose of tunneling UDP multicast 764 traffic to the receivers (i.e., End-Points). The AMT Relay will 765 receive the traffic natively from the multicast media source and 766 will replicate the stream on behalf of the downstream AMT 767 Gateways, encapsulating the multicast packets into unicast 768 packets and sending them over the tunnel toward the AMT Gateway. 769 In addition, the AMT Relay may perform various usage and 770 activity statistics collection. This results in moving the 771 replication point closer to the end user, and cuts down on 772 traffic across the network. Thus, the linear costs of adding 773 unicast subscribers can be avoided. However, unicast replication 774 is still required for each requesting End-Point within the 775 unicast-only network. 777 o AMT Gateway (GW): The Gateway will reside on an End-Point - this 778 may be a Personal Computer (PC) or a Set Top Box (STB). The AMT 779 Gateway receives join and leave requests from the Application 780 via an Application Programming Interface (API). In this manner, 781 the Gateway allows the End-Point to conduct itself as a true 782 Multicast End-Point. The AMT Gateway will encapsulate AMT 783 messages into UDP packets and send them through a tunnel (across 784 the unicast-only infrastructure) to the AMT Relay. 786 The simplest AMT Use Case (section 3.3) involves peering points that 787 are not multicast enabled between two multicast enabled AD's. An AMT 788 tunnel is deployed between an AMT Relay on the AD 1 side of the 789 peering point and an AMT Gateway on the AD 2 side of the peering 790 point. One advantage to this arrangement is that the tunnel is 791 established on an as needed basis and need not be a provisioned 792 element. The two AD's can coordinate and advertise special AMT Relay 793 Anycast addresses with each other. Alternately, they may decide to 794 simply provision Relay addresses, though this would not be an 795 optimal solution in terms of scalability. 797 Use Cases 3.4 and 3.5 describe more complicated AMT situations as 798 AD-2 is not multicast enabled. For these cases, the End User device 799 needs to be able to setup an AMT tunnel in the most optimal manner. 800 There are many methods by which relay selection can be done 801 including the use of DNS based queries and static lookup tables 802 [RFC7450]. The choice of the method is implementation dependent and 803 is up to the network operators. Comparison of various methods is out 804 of scope for this document; it is for further study. 806 An illustrative example of a relay selection based on DNS queries 807 and Anycast IP addresses process for Use Cases 3.4 and 3.5 is 808 described here. Using an Anycast IP address for AMT Relays allows 809 for all AMT Gateways to find the "closest" AMT Relay - the nearest 811 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 813 edge of the multicast topology of the source. Note that this is 814 strictly illustrative; the choice of the method is up to the network 815 operators. The basic process is as follows: 817 o Appropriate metadata is obtained by the EU client application. The 818 metadata contains instructions directing the EU client to an 819 ordered list of particular destinations to seek the requested 820 stream and, for multicast, specifies the source location and the 821 group (or stream) ID in the form of the "S,G" data. The "S" 822 portion provides the URI (name or IP address) of the source of the 823 multicast stream and the "G" identifies the particular stream 824 originated by that source. The metadata may also contain alternate 825 delivery information such as the address of the unicast form of 826 the content to be used, for example, if the multicast stream 827 becomes unavailable. 829 o Using the information from the metadata, and possibly information 830 provisioned directly in the EU client, a DNS query is initiated in 831 order to connect the EU client/AMT Gateway to an AMT Relay. 833 o Query results are obtained, and may return an Anycast address or a 834 specific unicast address of a relay. Multiple relays will 835 typically exist. The Anycast address is a routable "pseudo- 836 address" shared among the relays that can gain multicast access to 837 the source. 839 o If a specific IP address unique to a relay was not obtained, the 840 AMT Gateway then sends a message (e.g., the discovery message) to 841 the Anycast address such that the network is making the routing 842 choice of particular relay - e.g., closest relay to the EU. (Note 843 that in IPv6 there is a specific Anycast format and Anycast is 844 inherent in IPv6 routing, whereas in IPv4 Anycast is handled via 845 provisioning in the network. Details are out of scope for this 846 document.) 848 o The contacted AMT Relay then returns its specific unicast IP 849 address (after which the Anycast address is no longer required). 850 Variations may exist as well. 852 o The AMT Gateway uses that unicast IP address to initiate a three- 853 way handshake with the AMT Relay. 855 o AMT Gateway provides "S,G" to the AMT Relay (embedded in AMT 856 protocol messages). 858 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 860 o AMT Relay receives the "S,G" information and uses the S,G to join 861 the appropriate multicast stream, if it has not already subscribed 862 to that stream. 864 o AMT Relay encapsulates the multicast stream into the tunnel 865 between the Relay and the Gateway, providing the requested content 866 to the EU. 868 4.3. Back Office Functions - Provisioning and Logging Guidelines 870 Back Office refers to the following: 872 o Servers and Content Management systems that support the delivery 873 of applications via multicast and interactions between AD's. 874 o Functionality associated with logging, reporting, ordering, 875 provisioning, maintenance, service assurance, settlement, etc. 877 4.3.1 Provisioning Guidelines 879 Resources for basic connectivity between AD's Providers need to be 880 provisioned as follows: 882 o Sufficient capacity must be provisioned to support multicast-based 883 delivery across AD's. 884 o Sufficient capacity must be provisioned for connectivity between 885 all supporting back-offices of the AD's as appropriate. This 886 includes activating proper security treatment for these back- 887 office connections (gateways, firewalls, etc) as appropriate. 888 o Routing protocols as needed, e.g. configuring routers to support 889 these. 891 Provisioning aspects related to Multicast-Based inter-domain 892 delivery are as follows. 894 The ability to receive requested application via multicast is 895 triggered via receipt of the necessary metadata. Hence, this 896 metadata must be provided to the EU regarding multicast URL - and 897 unicast fallback if applicable. AD-2 must enable the delivery of 898 this metadata to the EU and provision appropriate resources for this 899 purpose. 901 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 903 Native multicast functionality is assumed to be available across 904 many ISP backbones, peering and access networks. If, however, native 905 multicast is not an option (Use Cases 3.4 and 3.5), then: 907 o EU must have multicast client to use AMT multicast obtained either 908 from Application Source (per agreement with AD-1) or from AD-1 or 909 AD-2 (if delegated by the Application Source). 910 o If provided by AD-1/AD-2, then the EU could be redirected to a 911 client download site (note: this could be an Application Source 912 site). If provided by the Application Source, then this Source 913 would have to coordinate with AD-1 to ensure the proper client is 914 provided (assuming multiple possible clients). 915 o Where AMT Gateways support different application sets, all AD-2 916 AMT Relays need to be provisioned with all source & group 917 addresses for streams it is allowed to join. 918 o DNS across each AD must be provisioned to enable a client GW to 919 locate the optimal AMT Relay (i.e. longest multicast path and 920 shortest unicast tunnel) with connectivity to the content's 921 multicast source. 923 Provisioning Aspects Related to Operations and Customer Care are 924 stated as follows. 926 Each AD provider is assumed to provision operations and customer 927 care access to their own systems. 929 AD-1's operations and customer care functions must have visibility 930 to what is happening in AD-2's network or to the service provided by 931 AD-2, sufficient to verify their mutual goals and operations, e.g. 932 to know how the EU's are being served. This can be done in two ways: 934 o Automated interfaces are built between AD-1 and AD-2 such that 935 operations and customer care continue using their own systems. 936 This requires coordination between the two AD's with appropriate 937 provisioning of necessary resources. 938 o AD-1's operations and customer care personnel are provided access 939 directly to AD-2's system. In this scenario, additional 940 provisioning in these systems will be needed to provide necessary 941 access. Additional provisioning must be agreed to by the two AD's 942 to support this option. 944 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 946 4.3.2 Application Accounting Guidelines 948 All interactions between pairs of AD's can be discovered and/or be 949 associated with the account(s) utilized for delivered applications. 950 Supporting guidelines are as follows: 952 o A unique identifier is recommended to designate each master 953 account. 954 o AD-2 is expected to set up "accounts" (logical facility generally 955 protected by login/password/credentials) for use by AD-1. Multiple 956 accounts and multiple types/partitions of accounts can apply, e.g. 957 customer accounts, security accounts, etc. 959 4.3.3 Log Management Guidelines 961 Successful delivery of applications via multicast between pairs of 962 interconnecting AD's requires that appropriate logs will be 963 exchanged between them in support. Associated guidelines are as 964 follows. 966 AD-2 needs to supply logs to AD-1 per existing contract(s). Examples 967 of log types include the following: 969 o Usage information logs at aggregate level. 970 o Usage failure instances at an aggregate level. 971 o Grouped or sequenced application access. 972 performance/behavior/failure at an aggregate level to support 973 potential Application Provider-driven strategies. Examples of 974 aggregate levels include grouped video clips, web pages, and sets 975 of software download. 976 o Security logs, aggregated or summarized according to agreement 977 (with additional detail potentially provided during security 978 events, by agreement). 979 o Access logs (EU), when needed for troubleshooting. 980 o Application logs (what is the application doing), when needed for 981 shared troubleshooting. 982 o Syslogs (network management), when needed for shared 983 troubleshooting. 985 The two AD's may supply additional security logs to each other as 986 agreed to by contract(s). Examples include the following: 988 o Information related to general security-relevant activity which 989 may be of use from a protective or response perspective, such as 991 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 993 types and counts of attacks detected, related source information, 994 related target information, etc. 995 o Aggregated or summarized logs according to agreement (with 996 additional detail potentially provided during security events, by 997 agreement). 999 4.4. Operations - Service Performance and Monitoring Guidelines 1001 Service Performance refers to monitoring metrics related to 1002 multicast delivery via probes. The focus is on the service provided 1003 by AD-2 to AD-1 on behalf of all multicast application sources 1004 (metrics may be specified for SLA use or otherwise). Associated 1005 guidelines are as follows: 1007 o Both AD's are expected to monitor, collect, and analyze service 1008 performance metrics for multicast applications. AD-2 provides 1009 relevant performance information to AD-1; this enables AD-1 to 1010 create an end-to-end performance view on behalf of the 1011 multicast application source. 1013 o Both AD's are expected to agree on the type of probes to be 1014 used to monitor multicast delivery performance. For example, 1015 AD-2 may permit AD-1's probes to be utilized in the AD-2 1016 multicast service footprint. Alternately, AD-2 may deploy its 1017 own probes and relay performance information back to AD-1. 1019 o In the event of performance degradation (SLA violation), AD-1 1020 may have to compensate the multicast application source per SLA 1021 agreement. As appropriate, AD-1 may seek compensation from AD-2 1022 if the cause of the degradation is in AD-2's network. 1024 Service Monitoring generally refers to a service (as a whole) 1025 provided on behalf of a particular multicast application source 1026 provider. It thus involves complaints from End Users when service 1027 problems occur. EUs direct their complaints to the source provider; 1028 in turn the source provider submits these complaints to AD-1. The 1029 responsibility for service delivery lies with AD-1; as such AD-1 1030 will need to determine where the service problem is occurring - its 1031 own network or in AD-2. It is expected that each AD will have tools 1032 to monitor multicast service status in its own network. 1034 o Both AD's will determine how best to deploy multicast service 1035 monitoring tools. Typically, each AD will deploy its own set of 1037 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1039 monitoring tools; in which case, both AD's are expected to 1040 inform each other when multicast delivery problems are 1041 detected. 1043 o AD-2 may experience some problems in its network. For example, 1044 for the AMT Use Cases, one or more AMT Relays may be 1045 experiencing difficulties. AD-2 may be able to fix the problem 1046 by rerouting the multicast streams via alternate AMT Relays. If 1047 the fix is not successful and multicast service delivery 1048 degrades, then AD-2 needs to report the issue to AD-1. 1050 o When problem notification is received from a multicast 1051 application source, AD-1 determines whether the cause of the 1052 problem is within its own network or within the AD-2 domain. If 1053 the cause is within the AD-2 domain, then AD-1 supplies all 1054 necessary information to AD-2. Examples of supporting 1055 information include the following: 1057 o Kind of problem(s). 1059 o Starting point & duration of problem(s). 1061 o Conditions in which problem(s) occur. 1063 o IP address blocks of affected users. 1065 o ISPs of affected users. 1067 o Type of access e.g., mobile versus desktop. 1069 o Locations of affected EUs. 1071 o Both AD's conduct some form of root cause analysis for 1072 multicast service delivery problems. Examples of various 1073 factors for consideration include: 1075 o Verification that the service configuration matches the 1076 product features. 1078 o Correlation and consolidation of the various customer 1079 problems and resource troubles into a single root service 1080 problem. 1082 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1084 o Prioritization of currently open service problems, giving 1085 consideration to problem impact, service level agreement, 1086 etc. 1088 o Conduction of service tests, including one time tests or a 1089 series of tests over a period of time. 1091 o Analysis of test results. 1093 o Analysis of relevant network fault or performance data. 1095 o Analysis of the problem information provided by the customer 1096 (CP). 1098 o Once the cause of the problem has been determined and the 1099 problem has been fixed, both AD's need to work jointly to 1100 verify and validate the success of the fix. 1102 o Faults in service could lead to SLA violation for which the 1103 multicast application source provider may have to be 1104 compensated by AD-1. Subsequently, AD-1 may have to be 1105 compensated by AD-2 based on the contract. 1107 4.5. Client Reliability Models/Service Assurance Guidelines 1109 There are multiple options for instituting reliability 1110 architectures, most are at the application level. Both AD's should 1111 work those out with their contract/agreement and with the multicast 1112 application source providers. 1114 Network reliability can also be enhanced by the two AD's by 1115 provisioning alternate delivery mechanisms via unicast means. 1117 5. Troubleshooting and Diagnostics 1119 Any service provider supporting multicast delivery of content should 1120 have the capability to collect diagnostics as part of multicast 1121 troubleshooting practices and resolve network issues accordingly. 1122 Issues may become apparent or identified either through network 1123 monitoring functions or by customer reported problems as described 1124 in section 4.4. 1126 It is expected that multicast diagnostics will be collected 1127 according to currently established practices [MDH-04]. However, 1128 given that inter-domain multicast creates a significant 1129 interdependence of proper networking functionality between providers 1131 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1133 there does exist a need for providers to be able to signal/alert 1134 each other if there are any issues noted by either one. 1136 Service providers may also wish to allow limited read-only 1137 administrative access to their routers via a looking-glass style 1138 router proxy to facilitate the debugging of multicast control state 1139 and peering status. Software implementations for this purpose is 1140 readily available [Traceroute], [draft-MTraceroute] and can be 1141 easily extended to provide access to commonly-used multicast 1142 troubleshooting commands in a secure manner. 1144 The specifics of the notification and alerts are beyond the scope of 1145 this document, but general guidelines are similar to those described 1146 in section 4.4 (Service Performance and Monitoring). Some general 1147 communications issues are stated as follows. 1149 o Appropriate communications channels will be established between 1150 the customer service and operations groups from both AD's to 1151 facilitate information sharing related to diagnostic 1152 troubleshooting. 1154 o A default resolution period may be considered to resolve open 1155 issues. Alternately, mutually acceptable resolution periods 1156 could be established depending on the severity of the 1157 identified trouble. 1159 6. Security Considerations 1161 From a security perspective, normal security procedures are expected 1162 to be followed by each AD to facilitate multicast delivery to 1163 registered and authenticated end users. Additionally: 1165 o Encryption - Peering point links may be encrypted per agreement 1166 for multicast delivery. 1168 o Security Breach Mitigation Plan - In the event of a security 1169 breach, the two AD's are expected to have a mitigation plan for 1170 shutting down the peering point and directing multicast traffic 1171 over alternative peering points. It is also expected that 1172 appropriate information will be shared for the purpose of 1173 securing the identified breach. 1175 DRM and Application Accounting, Authorization and Authentication 1176 should be the responsibility of the multicast application source 1178 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1180 provider and/or AD-1. AD-1 needs to work out the appropriate 1181 agreements with the source provider. 1183 Network has no DRM responsibilities, but might have authentication 1184 and authorization obligations. These though are consistent with 1185 normal operations of a CDN to insure end user reliability, security 1186 and network security. 1188 AD-1 and AD-2 should have mechanisms in place to ensure proper 1189 accounting for the volume of bytes delivered through the peering 1190 point and separately the number of bytes delivered to EUs. For 1191 example, [BCP38] style filtering could be deployed by both AD's to 1192 ensure that only legitimately sourced multicast content is exchanged 1193 between them. 1195 Authentication and authorization of EU to receive multicast content 1196 is done at the application layer between the client application and 1197 the source. This may involve some kind of token authentication and 1198 is done at the application layer independently of the two AD's. If 1199 there are problems related to failure of token authentication when 1200 end-users are supported by AD-2, then some means of validating 1201 proper working of the token authentication process (e.g., back-end 1202 servers querying the multicast application source provider's token 1203 authentication server are communicating properly) should be 1204 considered. Implementation details are beyond the scope of this 1205 document. 1207 7. IANA Considerations 1209 No considerations identified in this document 1211 8. Conclusions 1213 This Best Current Practice document provides detailed Use Case 1214 scenarios for the transmission of applications via multicast across 1215 peering points between two Administrative Domains. A detailed set of 1216 guidelines supporting the delivery is provided for all Use Cases. 1218 For Use Cases involving AMT tunnels (cases 3.4 and 3.5), it is 1219 recommended that proper procedures are implemented such that the 1220 various AMT Gateways (at the End User devices and the AMT nodes in 1221 AD-2) are able to find the correct AMT Relay in other AMT nodes as 1222 appropriate. Section 4.2 provides an overview of one method that 1223 finds the optimal Relay-Gateway combination via the use of an 1224 Anycast IP address for AMT Relays. 1226 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1228 9. References 1230 9.1. Normative References 1232 [RFC2784] D. Farinacci, T. Li, S. Hanks, D. Meyer, P. Traina, 1233 "Generic Routing Encapsulation (GRE)", RFC 2784, March 2000 1235 [RFC3376] B. Cain, et al, "Internet Group Management Protocol, 1236 Version 3", RFC 3376, October 2002 1238 [RFC3810] R. Vida and L. Costa, "Multicast Listener Discovery 1239 Version 2 (MLDv2) for IPv6", RFC 3810, June 2004 1241 [RFC4760] T. Bates, et al, "Multiprotocol Extensions for BGP-4", RFC 1242 4760, January 2007 1244 [RFC4604] H. Holbrook, et al, "Using Internet Group Management 1245 Protocol Version 3 (IGMPv3) and Multicast Listener Discovery 1246 Protocol Version 2 (MLDv2) for Source Specific Multicast", RFC 4604, 1247 August 2006 1249 [RFC4609] P. Savola, et al, "Protocol Independent Multicast - Sparse 1250 Mode (PIM-SM) Multicast Routing Security Issues and Enhancements", 1251 RFC 4609, August 2006 1253 [RFC7450] G. Bumgardner, "Automatic Multicast Tunneling", RFC 7450, 1254 February 2015 1256 [RFC7761] B. Fenner, et al, "Protocol Independent Multicast - Sparse 1257 Mode (PIM-SM): Protocol Specification (Revised), RFC 7761, March 1258 2016 1260 [BCP38] P. Ferguson, et al, "Network Ingress Filtering: Defeating 1261 Denial of Service Attacks which employ IP Source Address Spoofing", 1262 BCP: 38, May 2000 1264 [BCP41] S. Floyd, "Congestion Control Principles", BCP 41, September 1265 2000 1267 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1269 9.2. Informative References 1271 [INF_ATIS_10] "CDN Interconnection Use Cases and Requirements in a 1272 Multi-Party Federation Environment", ATIS Standard A-0200010, 1273 December 2012 1275 [MDH-04] D. Thaler, et al, "Multicast Debugging Handbook", IETF I-D 1276 draft-ietf-mboned-mdh-04.txt, May 2000 1278 [Traceroute] http://traceroute.org/#source%20code 1280 [draft-MTraceroute] H. Asaeda, K, Meyer, and W. Lee, "Mtrace Version 1281 2: Traceroute Facility for IP Multicast", draft-ietf-mboned-mtrace- 1282 v2-16, October 2016, work in progress 1284 10. Acknowledgments 1286 The authors would like to thank the following individuals for their 1287 suggestions, comments, and corrections: 1289 Mikael Abrahamsson 1291 Hitoshi Asaeda 1293 Dale Carder 1295 Tim Chown 1297 Leonard Giuliano 1299 Jake Holland 1301 Joel Jaeggli 1303 Albert Manfredi 1305 Stig Venaas 1307 IETF I-D Multicast Across Inter-Domain Peering Points September 2017 1309 Authors' Addresses 1311 Percy S. Tarapore 1312 AT&T 1313 Phone: 1-732-420-4172 1314 Email: tarapore@att.com 1316 Robert Sayko 1317 AT&T 1318 Phone: 1-732-420-3292 1319 Email: rs1983@att.com 1321 Greg Shepherd 1322 Cisco 1323 Phone: 1324 Email: shep@cisco.com 1326 Toerless Eckert 1327 Futurewei Technologies Inc. 1328 Phone: 1329 Email: tte@cs.fau.de 1331 Ram Krishnan 1332 SupportVectors 1333 Phone: 1334 Email: ramkri123@gmail.com