Morphing distribution trees—On the evolution of multicast states under mobility and an adaptive routing scheme for mobile SSM sources

Abstract

Source Specific Multicast (SSM) promises a wider dissemination of group distribution services than Any Source Multicast, as it relies on simpler routing strategies with reduced demands on the infrastructure. However, SSM is designed forá priori known and changeless addresses of multicast sources and thus withstands any easy extension to mobility. Up until now only few approaches arose from the Internet research community, leaving SSM source mobility as a major open problem. The purpose of this paper is twofold. At first we analyze characteristic properties of multicast shortest path trees evolving under source mobility. Analytically and by stochastic simulations we derive measures on the complexity of SSM routing under source mobility. At second we introduce a straightforward extension to multicast routing for transforming (morphing) source specific delivery trees into optimal trees rooted at a relocated source. All packet forwarding is done free of tunneling. Multicast service disruption and signaling overhead for the algorithms remain close to minimal. Further on we evaluate the proposed scheme using both, analytical estimates and stochastic simulations based on a variety of real-world Internet topology data. Detailed comparisons are drawn to bi-directional tunneling, as well as to proposals on concurrent distribution trees.

Multicast Mobility in Mobile IP Version 6 (MIPv6): Problem Statement and Brief Survey

“…By the self-similar nature, the persistent sub-trees (of previous and next distribution tree), rooted at any such intersection point, exhibit again the scaling law behavior, are tall-shaped with nodes of mainly low degree and thus likely to coincide. Tree alterations under mobility have been studied in [26], both analytically and by simulations. It was found that even in large networks and for moderate receiver numbers more than 80% of the multicast router states remain invariant under a source handover.…”

A Light-Weight Implementation Scheme of the Tree Morphing Protocol for Mobile Multicast Sources

“…In the first case a router will extract the group address from the type 7 routing header, implement an (nCoA, HoA, G) state in accordance with source route forwarding and transmit the packet towards pDR. In the second case a router will operate the STATE INJECTION and the EXTENDED FORWARDING Algorithms as described in our previous publication [21].…”

“…[21] for a thorough evaluation of its algorithmic performance. The quality of the proposed realization can be judged from overheads introduced by signaling load, operational processing and implementation complexity, as well as from its robustness against perturbed network conditions or security threads.…”

“…Only limited work has been dedicated to multicast source mobility, which poses the more delicate problem [18,22]. The Tree Morphing protocol [20,21], one of the few approaches to SSM source mobility management, enables immediate, unencapsulated multicast data transmission subsequent to Mobile IPv6 handovers.…”

P2P Mobile Multimedia Group Conferencing: Combining SIP, SSM and Scalable Adaptive Coding for Heterogeneous Networks

“…Conferencing parties request seamless real-time performance of a mobility aware group communication service, thereby attaining the simultaneous roles of mobile multicast listener and source. Up until now only limited work has been dedicated to multicast source mobility, which poses the more delicate problem [5,6].…”