MeGaDiP: a wide-area media gateway discovery protocol

In wide-area and heterogeneous environments, it is necessary to deploy media gateways at strategic locations within the networks, in order to deliver customized and composable multimedia services to individual users. In many cases, the media gateways have to be dynamically discovered, because (1) a host may not know a priori all the media gateways it will possibly use, and (2) the change of host location or end-to-end resource condition can make a known media gateway no longer valid. However, current general service location mechanisms are not sufficient to perform media gateway discovery. In this paper, we present MeGaDiP, a wide-area Media Gateway Discovery Protocol. It is based on the same basic architecture of the general service location mechanisms, and can be seen as a heuristics to be used first when discovering a media gateway. We also propose an extension of MeGaDiP using a hierarchical architecture to further improve the discovery success rate. The initial performance results from both our prototype implementation and simulation show the soundness of MeGaDiP