1. Inter-domain AMT Multicast Use Case Discussion Proposal for AMT Multicast Source-AMT Connectivity Model For Inter-connected Networks (AS’s) 1

2. Problem  With the existing model for AMT anycast addressing, when an end-user requests multicast content via AMT, the request will be routed to the nearest AMT Relay, which could be in the requestor’s local network or any other network.  For the connection to be successful, the end-user must reach an AMT Relay that has multicast connectivity to the Multicast Source that originates the content.  If the AMT Relay reached by the end-user does not have multicast connectivity to the source, the result will be a failure to obtain the content via multicast.  If the AMT Relay reached does have multicast connectivity with the source, but is located in a distant network, in many cases the following highly inefficient AMT tunnel will result. Anycast Addressing Issue AMT Relay Internet Multicast Source Multicast-enabled Source Network End-User’s Network AMT Gateway  A way is needed to route an anycast AMT request to the closest AMT Relay that has multicast connectivity to the requested Source. This could be a local (to the end-user) AMT Relay on another provider’s network, or an AMT Relay in the Multicast Source’s network, or an AMT Relay in an intermediate network. 2

3. 11/29/2010 Page 3 © 2011 AT&T Intellectual Property. All rights reserved. Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 Federation A Federation B Network Architecture and Connectivity AMT DNS 2 AMT DNS 1 AMT DNS 3 3 Multicast-enabled interconnection Unicast-only interconnection Federation AFederation B andnetworks are internally multicast-enabled Networks 7 and 8 are not multicast-enabled Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

4. Requirements for Solution Only three requirements: 1.In a network that hosts a Multicast Source, the Authoritative DNS server has an “in-addr.arpa” address entry for the Source IP. E.g., for S1 of (S1,G1) = 1.x.y.z, there is an entry in Authoritative DNS 1 for “z.y.x.1.in-addr.arpa” that maps to the anycast address described in #2 below. 2.All networks (members of the same “Federation”) that have multicast connectivity to S1 and wish to server content from that Source, must have “AMT DNS” servers reachable by the same anycast address, and the entries in those AMT DNS servers map to the AMT Relays in their own networks. E.g., AMT DNS 1, AMT DNS 2, and AMT DNS 3 in the diagrams are reachable by the same anycast address, and they have entries that map to the address of their own network’s AMT Relays. So, AMT DNS 1 maps queries to AMT Relay(s) 1, AMT DNS 2 maps to AMT Relay(s) 2, AMT DNS 3 maps to AMT Relay(s) 3. 3.AMT Gateways seek to find an AMT Relay by the deterministic construction of an “in-addr.arpa” DNS query* of the form “z.y.x.A.in-addr.arpa” Where “A” is (e.g.) the class A address allocated to the Source’s host network, and “A.x.y.z” is the IP address of the Source specified in the (S,G). 4 * Instead of using the global AMT anycast address

5. 11/29/2010 Page 5 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 1 “z.y.x.1.in-addr.arpa” End-user application on Network 8 wants content on S1 (1.x.y.z), the AMT Gateway determines it does not have native multicast access to S1, seeks to connect via AMT Relay, constructs DNS query for “z.y.x.1.in-addr.arpa” AMT DNS 2 AMT DNS 1 AMT DNS 3 5 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

6. 11/29/2010 Page 6 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 2 “z.y.x.1.in-addr.arpa” Network 8 Local DNS performs recursive queries, eventually finds Authoritative DNS 1 AMT DNS 2 AMT DNS 1 AMT DNS 3 6 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

7. 11/29/2010 Page 7 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 3 “a.b.c.d” Anycast Network 1 Authoritative DNS redirects query to “a.b.c.d”, the anycast address for all Federation A “AMT DNS” servers (AMT DNS 1, 2, & 3) AMT DNS 2 AMT DNS 1 AMT DNS 3 7 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

8. 11/29/2010 Page 8 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 4 Send query for “z.y.x.1.in-addr.arpa” to DNS server at “a.b.c.d” Anycast IP Network 8 Local DNS sends a query for “z.y.x.1.in-addr.arpa” to “a.b.c.d”, the anycast address for all Federation A “AMT DNS” servers, which is naturally routed to AMT DNS 3, the closest AMT DNS server in Federation A AMT DNS 2 AMT DNS 1 AMT DNS 3 8 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

9. 11/29/2010 Page 9 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 5 AMT Relay 3 IP Address Entries in Network 3 AMT DNS map to Network 3’s own AMT Relays because Network 3 has multicast connectivity to S1, thus AMT DNS 3 returns IP address of AMT Relay 3 AMT DNS 2 AMT DNS 1 AMT DNS 3 9 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

10. 11/29/2010 Page 10 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 6 AMT Relay 3 IP Address End-user receives IP address of optimal AMT Relay for S1 AMT DNS 2 AMT DNS 1 AMT DNS 3 10 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

11. 11/29/2010 Page 11 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway End-user GW establishes optimal tunnel for content at S1 Multicast AMT Tunnel AMT DNS 2 AMT DNS 1 AMT DNS 3 11 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

12. 11/29/2010 Page 12 Network 2 AMT Relay 2 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 Network 6 AMT Relay 6 Network 5 AMT Relay 5 AMT DNS 2 AMT DNS 1 AMT DNS 3 AMT DNS 5 AMT DNS 4 AMT DNS 6 Multicast Source 5 Network Architecture and Connectivity – End-user Wants Content at Multicast Source 5 12 Federation A Federation B Network 1 Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

13. 11/29/2010 Page 13 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 Network 6 AMT Relay 6 Network 5 AMT Relay 5 AMT Gateway 1 “z.y.x.5.in-addr.arpa” End-user Gateway determines no native multicast access to S5 (IP address = “5.x.y.z”), seeks to connect via AMT Relay, queries DNS to resolve “z.y.x.5.in-addr.arpa” Multicast Source 5 AMT DNS 5 AMT DNS 4 AMT DNS 6 AMT DNS 2 AMT DNS 1 AMT DNS 3 13 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

14. 11/29/2010 Page 14 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 Network 6 AMT Relay 6 Network 5 AMT Relay 5 AMT Gateway 2 “z.y.x.5.in-addr.arpa” Network 8 local DNS performs recursive queries, finds Authoritative DNS 5 Multicast Source 5 AMT DNS 5 AMT DNS 4 AMT DNS 6 AMT DNS 2 AMT DNS 1 AMT DNS 3 14 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

15. 11/29/2010 Page 15 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 Network 6 AMT Relay 6 Network 5 AMT Relay 5 AMT Gateway 3 “e.f.g.h” Anycast Authoritative DNS 5 redirects query to “e.f.g.h”, the Anycast address for all Federation B “AMT DNS” servers (AMT DNS 4, 5, & 6) Multicast Source 5 AMT DNS 5 AMT DNS 4 AMT DNS 6 AMT DNS 2 AMT DNS 1 AMT DNS 3 15 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

16. 11/29/2010 Page 16 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 4 Send query for “z.y.x.5.in-addr.arpa” to DNS server at “e.f.g.h” Anycast IP Network 8 Local DNS sends a query for “z.y.x.5.in-addr.arpa” to “e.f.g.h”, the anycast address for Federation B “AMT DNS” servers, which is naturally routed to AMT DNS 6, the closest AMT DNS server in Federation B AMT DNS 2 AMT DNS 1 AMT DNS 3 16 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

17. 11/29/2010 Page 17 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 5 AMT Relay 6 IP Address Entries in Network 6 AMT DNS map to Network 6’s own AMT Relays because Network 6 has multicast connectivity to S5, thus AMT DNS 6 returns IP address of AMT Relay 6 AMT DNS 2 AMT DNS 1 AMT DNS 3 17 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

18. 11/29/2010 Page 18 Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 AMT DNS 4 Network 6 AMT Relay 6 AMT DNS 6 Network 5 AMT Relay 5 AMT DNS 5 AMT Gateway 6 AMT Relay 6 IP Address End-user receives IP address of optimal AMT Relay for S5 AMT DNS 2 AMT DNS 1 AMT DNS 3 18 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6

19. 11/29/2010 Page 19 © 2011 AT&T Intellectual Property. All rights reserved. Network 2 AMT Relay 2 Network 1 AMT Relay 1 Multicast Source 1 Network 7 Local DNS 7 Network 8 Local DNS 8 Network 3 AMT Relay 3 Network 4 AMT Relay 4 Network 6 AMT Relay 6 Network 5 AMT Relay 5 AMT Gateway End-user GW establishes optimal tunnel for content at S5 Multicast AMT Tunnel AMT DNS 2 AMT DNS 1 AMT DNS 3 Multicast Source 5 AMT DNS 5 AMT DNS 4 AMT DNS 6 19 Federation A Federation B Author. DNS 1 Author. DNS 2 Author. DNS 3 Author. DNS 4 Author. DNS 5 Author. DNS 6