1 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Mobile IP Multicasting with Host Mobility Locality Gihwan Cho Chonbuk University

2 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Outline  Internet host mobility support  Multicasting  Problems identified  Existing works  Host movement locality approach Reference 1. A. Acharya, A. Bakre and B. R. Badrinath, “IP Multicast Extensions for Mobile Internetworking,” IEEE INFOCOM’96, 1996, pp V. Chikarmane et al. “Multicast Support for Mobile Hosts Using Mobile IP: Design Issues and Proposed Architecture,” ACM/Baltzer Mobile Networking and Applications, 3(4), pp , Jan S. Deering, “Host Extensions for IP Multicasting,” RFC 1112, Aug C. Perkins, “IP Mobility Support,” RFC 2002, Oct. 1996

3 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Internet Host Mobility Support  Prerequisite sender may (need) not know the destination is moving datagrams are routed based on IP address  Mobile IP aims to allow transparent routing of datagrams to mobile hosts in the Internet  Three protocol steps agent discovery location registration datagram tunneling

4 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Triangle Routing Internet MA k MA pMA s {MH k, -} MA a {MH a, *} MH a MH k {MH k, *} MH k Registration {MH k, MA s} MH k Discovery Tunneling {MH k, MA s} MH k {MH k, MA s} MH k

5 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Multicasting  Transmitting the same information to a selective set of destination aims to resource saving by arranging for network links to be shared  Two building blocks membership management : IGMP multicast routing protocol : DVMRP, CBT, PIM  DVMRP composes a multicast tree of the reverse shortest paths from each destination to the source

6 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 IGMP & DVMRP MR prune Membership query and reply Membership query and reply graft

7 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Tunnel Convergence Problem  When multicasting meets Internet host mobility support MR MA_a MH_a MH_s1 MH_s2 MA_k MA_s

8 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 In Addition,  With mobility, delay and disconnection MA n MA k MA i MH i1 MA p MH k3 MH k2 MH k1 received twice partially received not received partially received disconnection orphan packet

9 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Arup’s Approach  Deliver datagrams to all subnets do not need to rebuild the multicast tree for host moves MR MA_a MH_a MH_s1 MH_s2 MA_k MA_s

10 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Vineet’s Approach  Designated multicast service server tried to resolve the tunnel convergence problem MR MA_a MH_a MH_s1 MH_s2 MA_k MA_s Designated Tunneling server Designated Tunneling server

11 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Host Mobility Locality  Boring professor model Computing Science (4 days) Computing Center (1/2 day) Company (1 day)

12 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Basic Idea  Find just the places where it is highly likely to be effectively utilized for packet routing  Local region for each mobile host a set of subnets which the mobile host moves often as a technical definition, a set of subnets that are visited by the host during the most recent time,  t then, our approach is to keep multicast paths for each of these subnets during  t as a result, the multicast routes may remain unchanged upon the host’s move, as long as the host moves around within the local region

13 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Local Region MR HA_a MH_a MH_s1 MH_s2 MA_k HA_s Local Region for MH_a

14 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Protocol Overview  Each MA maintains a group view table  Each MH maintains a group view list  Each subnet within a local region maintains the corresponding group view table until the life_time expires  When a host moves out its local region, the previous MA forwards in-flight datagrams to current MA until the forwarding_time expires

15 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Handoff Procedure Current MA HA Previous MA MH Refreshes forwarding_time Registration Req. Registration Rep. Forwarding Rep. Forwarding Req. Starts Join operation Compares {MH’s gourp list, MA’s group view} Creates MH’s group view Finish Join operation Expire forwarding_time Forwarding period from the previous MA Multicast tree join period

16 Chonbuk University, DCLAB, ghcho APCC : Wireless Internet Nov. 2, 2000 Summary  Internet multicast supporting host mobility brings new challenges as: tunnel convergence triangle routing delivery semantics: not, duplicated, partial orphan packet