Application level multicast schemes have traditionally been evaluated with respect to the efficiency penalties incurred in migrating the multicast functionality from the network layer to the application layer. We argue that the current performance measures, and therefore design strategies, are incomplete as they do not consider transience of peers. The routers in application level multicast systems are participant clients, and not infrastructure units. As such, the assumptions on the behavior of these application routers are significantly different from the infrastructure routing units that traditional research has dealt with, especially in a peer-to-peer setting where peers are multi-use and the management is decentralized. We argue that the transience in peer behavior has implications on end-performance enabled. We outline a design philosophy that seeks to separate policy decisions in handling peer behavior from the end-application at a basic infrastructural peering layer. As a proof of concept, we have implemented a peering layer prototype, which is available for download.