Flow Control Method For Abr Service In An Asynchronous Transfer Mode Network

Abstract

An Improved Flow Control Method For Abr Service In An Atm Network. In Particular, A Dual Local/Global Ingress Flow Control Method For Abr Service In A Distributed Ingress Queueing Switch Including A Plurality Of Ingress Buffer-Pools, At Least One Shared Buffer-Pool And A Plurality Of Egress Buffer-Pools. Utilization Of The Egress Port Of Each Shared Buffer-Pool Is Periodically Measured And Together With The Current State Of The Global-Ingress Control Forms The Basis For Toggling Global-Ingress Control In An Active/Inactive State. Queue-Length Based Flow Control Algorithms Such As Dmrca Are Applied To Each Resource Management Cell For The Egress Subport Queue And Ingress Flow Queue Through Which The Resource Management Cell Passes To Determine The Egress And Local-Ingress Congestion Marking Values, Respectively, For The Resource Management Cell. In Addition, Global-Ingress Congestion Is Detected By Applying A Queue-Length Based Flow Control Algorithm To The Summation Of The Ingress Flow Queues Contributing To The Shared Buffer-Pool Egress Port Through Which The Resource Management Cell Passed. If Global-Ingress Control Is Active Then The Resource Management Cell Is Marked Based On The Merged Egress, Global-Ingress, Local-Ingress Congestion Marking Values And The Congestion Marking Values Originally Carried By The Resource Management Cell. Otherwise The Resource Management Cell Is Marked Based On The Merged Egress, Local-Ingress Congestion Marking Values And The Congestion Marking Values Originally Carried By The Resource Management Cell.