An Evaluation of Opportunistic Native Multicast

Hybrid multicast opportunistically combines Application Layer Multicast and native multicast protocols. This paper presents an evaluation of Opportunistic Native Multicast which uses the AMT multicast tunnelling protocol. We describe our opportunistic multicasting approach that tries to solve the islands phenomenon by building unicast tunnels to connect these islands while attempting to utilise the native multicast capability of the islands. It is expected that this hybrid approach will improve both efficiency and availability of multicast. We compare our approach to the ALM protocol SCRIBE. The comparison here was done using five metrics: Stress, Stretch, intra-island traffic, interisland traffic and Delivery rate. In all of them, our proposed model has shown improved results over ALM. Moreover, we investigated what effect the number of islands that the receivers are distributed into, has on performance

A simulation model for hybrid multicast

In order to achieve one-to-many data delivery on the internet, native multicast is used and implemented in some parts of the Internet. On the other hand, application layer multicast (ALM), which uses P2P overlays (overlay multicast, OM), can be used to create multicast trees and deliver the data at the application layer. Despite Native Multicast being more efficient than Application Layer Multicast, it is not deployed widely. A hybrid multicast protocol has been proposed that opportunistically combines overlay multicast protocols and native multicast protocols to create and maintain hybrid multicast trees. The design for hybrid multicast trees leverages the AMT multicast tunneling protocol. It is expected that this hybrid approach will improve both efficiency and availability of multicast. This paper presents a simulation model for the Oversim/Omnet++ simulation framework to evaluate the performance of the hybrid multicast approach. Our model combines both a scalable overlay and a detailed network layer model that includes routers with native multicast support

Opportunistic native multicast under churn

In this paper we investigate the behaviour of Opportunistic Native Multicast under node churn. Previously, we have introduced an Opportunistic Native Multicast approach that facilitates native multicast where possible and which reverts to using overlay multicast when needed. Here, we are evaluating Overlay Native Multicast in a more realistic environment considering the effect of network churn and propose election algorithms to offer resilience and adaptivity required in the real world. We have developed a mechanism where the network can autonomously and deterministically elect a primary node for each multicast island. We have further investigated ways to improve the efficiency and responsiveness of the protocol by introducing a secondary node selection process. We have tested our proposed improvements using Oversim simulation. We show that Opportunistic Native Multicast can achieve success rates well above 90 percent despite realistic levels of node churn