Proposal for AMT Multicast Interdomain Multicast SourceAMT Connectivity

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

Problem § § Anycast Addressing Issue 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. End-User’s Network Source Network Multicast-enabled Internet AMT Relay AMT Gateway Multicast Source § 2 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.

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

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 S 1 of (S 1, G 1) = 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 S 1 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. 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). * Instead of using the global AMT anycast address 4

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

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

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) Local DNS 7 Author. DNS 5 Network 7 AMT DNS 5 AMT Relay 5 Network 5 Federation A Multicast Source 1 Network 1 Author. DNS 1 Federation B AMT Relay 1 AMT DNS 4 Network 4 AMT DNS 1 Author. DNS 4 Author. DNS 3 AMT DNS 3 Author. DNS 2 AMT Relay 4 AMT DNS 6 AMT Relay 3 Network 6 Network 3 AMT Relay 2 3 “a. b. c. d” Anycast Network 2 Local DNS 8 AMT Gateway 7 AMT Relay 6 Network 8 Author. DNS 6

Local DNS 7 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 Author. DNS 5 in Federation A Network 7 AMT DNS 5 AMT Relay 5 Network 5 Federation A Multicast Source 1 Network 1 Author. DNS 1 Federation B AMT Relay 1 AMT DNS 4 Network 4 AMT DNS 1 Author. DNS 4 Author. DNS 3 AMT DNS 3 Author. DNS 2 AMT Relay 4 AMT DNS 6 AMT Relay 3 Network 6 Network 3 Author. DNS 6 AMT Relay 2 Network 2 4 Send query for “z. y. x. 1. in-addr. arpa” to DNS server at “a. b. c. d” Anycast IP Local DNS 8 AMT Gateway 8 AMT Relay 6 Network 8

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

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

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

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

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

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

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) Local DNS 7 Author. DNS 5 Network 7 AMT Relay 5 AMT DNS 5 Network 5 Federation A Multicast Source 1 Network 1 Author. DNS 1 Federation B AMT Relay 1 Network 4 Author. DNS 3 AMT DNS 2 AMT Relay 4 AMT DNS 1 Author. DNS 2 AMT DNS 6 AMT Relay 3 AMT Relay 6 Network 3 Author. DNS 6 AMT Relay 2 3 Network 2 “e. f. g. h” Anycast Local DNS 8 AMT Gateway 15 Multicast Source 5 Network 8

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 Local DNS 7 Author. DNS 5 Network 7 AMT DNS 5 AMT Relay 5 Network 5 Federation A Multicast Source 1 Network 1 Author. DNS 1 Federation B AMT Relay 1 AMT DNS 4 Network 4 AMT DNS 1 Author. DNS 4 Author. DNS 3 AMT DNS 3 Author. DNS 2 AMT Relay 4 AMT DNS 6 AMT Relay 3 Network 6 Network 3 Author. DNS 6 AMT Relay 2 Network 2 4 Send query for “z. y. x. 5. in-addr. arpa” to DNS server at “e. f. g. h” Anycast IP Local DNS 8 AMT Gateway 16 AMT Relay 6 Network 8

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

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

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