Enhanced call: a paradigm for applications with dynamic client-membership in ATM networks

The traditional monolithic call concept is inefficient in representing multi-point applications with dynamic client-membership and client-level binding. We propose a new high-level network object called the enhanced call. Clients present at its setup time are called primary clients. Clients that add on to an existing call are called secondary clients. To reduce the overhead associated with end-to-end connection admission of every secondary client, virtual channel links (VCLs) are reserved statistically at enhanced call setup. This reduces the likelihood of secondary clients being blocked due to lack of available bandwidth. This paper addresses issues related to admission management of the enhanced call. First, we describe a network architecture required to implement the enhanced call. Client-level descriptors are proposed for the new call object. These descriptors are used to construct a worst-case model for secondary-client arrivals. The distribution of the number of carried VCLs in a call is obtained on each link of the call multicast tree. In particular, the VCL-size stochastic process is shown to be semi-regenerative with respect to an underlying Markov renewal process, and its steady-state distribution is computed. A call-admission scheme is developed based on the VCL-size distribution of a call. To ensure that secondary clients comply with the call descriptors, we define conformance in terms of global and local regulators. Following the admission of a call, these regulators test each arriving secondary client to check if it is conforming. Conforming secondary clients are set up without an end-to-end admission procedure