Multicast group membership management

Abstract

Multicast services, assisted by special hardware, are being considered as a part of high-speed wide-area networks (WANs) in order to support new generations of multiuser applications. This paper describes an application multicast service for high-speed WANs which is capable of exploiting multicast hardware. Indeed, this research was conducted in context of the spanning tree hardware structure of PARIS and of plaNET, the pioneering broadband experimental networks that predated ATM. The results of this research were also included in IBM's ATM, called Networking BroadBand Services (NBBS). We achieve modularity and low cost by assigning to distinct components the separate problems of: 1) naming groups; 2) finding group members in a network; 3) configuring multicast hardware; and 4) delivering multicast messages in sequence. This modularity enables, for example, both the multicast to a group to which the user initiates the joining (formed by using 1 and 2 above), on one hand, and to groups computed by the source on the other hand. We give the overall organization of our service and then describe in detail the methods used to solve the first two of the subproblems.