Treemap – The Fast Routing Convergence Method for Application Layer Multicast

1. Treemap – The Fast Routing Convergence Method for Application Layer Multicast Khoa T.Phan†, Nam Thoai†, Eiichi MuramotoΩ Ettikan K.K¥, Lim Boon Ping¥, P.Y. TanΔ †Ho Chi Minh city University of Technology (HCMUT) ΩImmersive Communication Task Force, Panasonic Corporation ¥Panasonic R&D Center Malaysia, ΔNetwork Team, PSL, Singapore IEEE CCNC 2010, Las Vegas, Nevada USA

2. Outline • Application Layer Multicast • Xcast6 – Explicit Multi-unicast (RFC 5058) • Xcast6 Treemap • Conclusions and Future work

3. Application Layer Multicast (ALM) Multicast functionality is implemented at end-hosts: • No special addresses needed. • No infrastructure upgrade required → easy in deployment. • No state per multicast group at routers → enhance scalability with number of groups. • However: • There is a performance penalty. • ALM does not leverage native multicast where it exists.

4. C B D R3 X2 X1 A X4 E F Xcast6 – Explicit Multi-unicast (1) • Xcast6 – RFC 5058 (November 2007). • An explicit list of unicast destination addresses is stored in IPv6 packet header. • No state per multicast group at routers → enhance scalability with number of groups. • Incremental deployment → Xcast6 packet can be tunneled through non-Xcast-aware routers. Datagram packet B C D E F B C D E F BC D E F B C D E F BCD E F B C D E F B C D E F • - X is Xcast-aware router • R is normal router B C D E F

5. C B D R3 R1 R2 A R4 E F Xcast6 – Explicit Multi-unicast (2) Issue:daisy-chain connection in the absence of Xcast-aware router → long latency and unreliable quality for applications. B CD E F BC D E F B C DE F B C D E F B C DEF • - X is Xcast-aware router • R is normal router

6. Xcast6 Treemap (1) Xcast6 Treemap is an extension of Xcast6. Our goals are: • Supporting ALM tree forwarding → solving the daisy-chain problem. • Running on the real Internet. • Supporting fast route adaptation when hosts dynamically join/leave • → better quality of service. • Leveraging network layer multicast where Xcast-aware routers exist.

7. A E F A B C D 1 0 0 2 0 2 B C D F E Xcast6 Treemap (2) Treemap – the technique to encode overlay multicast tree: List of destinations List of children • List of destinations: a list of nodes in breadth first order. • List of children: a list of number of children for each node in breadth first order.

8. Xcast6 Treemap (3) Integrating the Treemap into Xcast6 header: • In Xcast6, “list of destinations” is in the routing header. • We add “list of children” to the destination option header. • With 32 bytes, “list of children” represents a maximum of 64 nodes.

9. B C D E F 2 0 2 0 0 B C D E F 2 0 2 0 0 BC D E F 2 0 2 0 0 B C D E F 2 0 2 0 0 C E B C D E F 2 0 2 0 0 F A B D Treemap representation The overlay tree Xcast6 Treemap (4) How Xcast6 Treemap work? B C D R3 R2 R1 A R4 E F

10. Xcast6 Treemap (5) Our goals: • Supporting ALM tree forwarding → solving daisy-chain problem. • Can run on the Internet (on IPv6). • Supporting fast route adaptation when hosts dynamically join/leave. • Leveraging network layer multicast where Xcast-aware routers exist.

11. - E leaves and the overlay route • changes to: • End-hosts do not update routing • table concurrently. • - E joins and the overlay route • changes to: • End-hosts do not update • routing table concurrently. E B A B E D C C D A B C D Xcast6 Treemap (6) Fast routing convergence A’s routing table A → B A B’s routing table B → C B → D B updates routing table B → C B → E B updates routing table B → C E updates routing table E → D D can’t receive data C updates routing table C → D Packet loss in ALMCast (*) ALMCast* (*) B.P. Lim, Ettikan K.K, et al. “Bandwidth Fair Application Layer Multicast for Multi-party Video Conference Application”, 6th Annual IEEE Consumer Communication and Networking Conferene (CCNC), 2009.

12. E joins and the overlay route changes to: A E B A B E E leaves and the overlay route changes to: D C C D A B C D Xcast6 Treemap (7) Fast routing convergence Treemap B C D2 0 0 Treemap B C E D2 0 1 0 Treemap B C D1 1 0 D can’t receive data Xcast6 Treemap

13. A F B C E D Xcast6 Treemap (8) Leveraging network layer multicast ALM B C D E F 2 0 2 0 0 B C D R3 X2 X1 R1 R2 A • Note: • X is Xcast-aware router • R is normal router R4 X4 E F Overlay tree

14. Daisy-chain form Xcast6 Treemap (9) Forwarding time Branched form *PC of Pentium IV 1.8GHz with 512MB RAM

15. Conclusions • No state per multicast group at routers → scalable with large number of groups. • Can run on the Internet (on IPv6). • Supporting ALM tree forwarding in the absence of Xcast-aware router. • Supporting fast route adaptation in application layer routing when hosts dynamically join/leave → better quality of service. • Leveraging network layer multicast where Xcast-aware routers exist. No Xcast router Network Xcast6 Treemap packet sends data as overlay tree User Have Xcast router Only care about the overlay network sends data in network layer multicast Black box

16. Future work • Large scale multicast group • Extend Xcast6 Treemap to support large multicast group. • Fast routing convergence algorithm for large multicast group. • Cross site testbed • SINET3 – the backbone network of universities in Japan. • SAM testbed with hosts located in Europe, US, Japan and Asia.

17. THANK YOU!

18. Sub-group Root node Sub-group Xcast6 Treemap with large group Not enough? N branches Maximum of 64 nodes per group Maximum of (64 * N) nodes Maximum of 64 nodes per sub-group

19. Outer IP Inner IP Routing header Destination option header Xcast6 Treemap packet Structure of an Xcast6 Treemap packet from A is sent to a group (B, C, D, E, F) Inner IP: src = A, dest = ALL_XCAST_NODES Outer IP: src = A, dest = B Routing header: list of dest = B C D E F bitmap = 1 1 1 1 1 Destination options header: Treemap = 2 0 2 0 0

20. B C D E F 2 0 2 0 0 Xcast6 Treemap How Xcast6 Treemap work? Outer IP = D Outer IP = C B C D E F B C D E F Outer IP = B B C D R3 X2 R1 A • - X is Xcast-aware router • R is normal router R4 E F