A scheme for the management of isochronous and asynchronous bandwidth in ring networks

This paper presents a scheme that manages bandwidth allocation and deallocation in ring local and metropolitan area networks. The scheme is based on dividing the total ring bandwidth into a number of 64 kbits/sec channels. Isochronous channels are allocated out of this total bandwidth in a dynamic manner. The maximum isochronous bandwidth that can be allocated is theoretically limited by the ring bandwidth. Release of isochronous channels is also implemented dynamically and in a distributed manner, with minimal intervention from the monitor station. In addition, the remaining bandwidth can be used for asynchronous communication. The scheme also allows a minimum amount of bandwidth to be reserved for asynchronous communication. Another feature of this scheme is that bandwidth portions used by isochronous and asynchronous channels do not interleave, and that the isochronous channels allocated to a certain call are contiguous. The paper also shows how this scheme can be adapted to the FDDI-II network