Scheduling and admission control for integrated-services networks: the Priority Token Bank

This paper proposes a new mechanism called the Priority Token Bank for admi ssion control, scheduling and policing in integrated-services networks. In such networks, both arrival processes and performance objectives can vary g reatly from one packet stream to another. There are two principal component s to the Priority Token Bask: accepting or rejecting requests to admit enti re packet streams, where acceptance means guaranteeing that the packet stre am's performance objectives will be met, and scheduling the transmission of packets such that performance objectives are met, even under heavy loads. To the extent possible, the performance of traffic is also optimized beyond the requirements. The performance achieved with the Priority Token Bank is compared to that of other typical algorithms. It is shown that, when opera ting under the constraint that the performance objectives of applications s uch as packet voice, video and bulk data transfer must be met in an ATM net work, the mean delay experienced by other traffic is much better with the P riority Token Bank. Furthermore, the admission control algorithm can guaran tee requirements will be met, and admit more traffic than the common altern atives. (C) 1999 Elsevier Science B.V. All rights reserved.