A network level channel abstraction for multimedia communication in real-time networks

The design of communication protocols to support guaranteed real-time communication for distributed multimedia systems is examined. A network level abstraction called φ-channel that supports the requirements of real-time applications is proposed. A φ-channel represents a fractional, simplex, end-to-end communication channel between a source and a destination. The channel is characterized by a set of specific performance parameters associated with its traffic. The required performance characteristics of a φ-channel are specified in terms of the packet maximum end-to-end delay and the maximum number of packets that can be sent over that delay. The primary attribute supported by the φ-channel is the on-time reliability. Based on the specified parameters, the underlying delivery system verifies the feasibility of supporting such a channel. The performance of an accepted φ-channel is guaranteed under any conditions, barring hardware failures. The basic scheme that the model uses to verify the feasibility of accepting a φ-channel and the run-time support used to guarantee its performance are described. The results of a simulation experiment implementing the basic functionalities of the proposed scheme are also presented