EFFECTIVE FLOW CONTROL FOR ABR MULTIPOINT-TO-MULTIPOINT SERVICES

Although many flow control schemes have been proposed for ABR (Available Bit Rate) multipoint-to-multipoint (mp-mp) services in ATM (Asynchronous Transfer Mode) networks, several issues remain to be resolved: bandwidth allocation definitions (BADs), and the effectiveness of those schemes. No consensus has been reached concerning the issue of criteria for allocating ABR bandwidth among multipoint connections, or between point-to-point and multipoint connections. On the other hand, existing mp-mp flow control schemes implement only one BAD, namely sourcebased allocation. This inflexibility can limit the application of those schemes. Moreover, our simulation results will show that they suffer from the problems of link under-utilization and/or noncompliance with the selected BAD. We propose a mp-mp flow control algorithm, the FCAM 1 algorithm, that supports a large set of BADs, provides correct rate allocations with fast convergence, and maximizes link utilization. Experimental results are presented to demonstrate the above advantages of the FCAM algorithm. 1