A Generalized Processor Sharing Approach to Flow Control in Integrated Services Networks: The Single Node Case.'

The problem of allocating network resources to the users of an integrated services net-work is investigated in the context of rate-based flow control. The network is assumed to be a virtual circuit, connection-based packet network. We propose a flexible and efficient multiplexing scheme called Generalized Processor Sharing (GPS) that when combined with leaky bucket admission control allows the network to make worst-case performance guaran-tees on throughput and delay. The scheme is flexible in that different users may be given widely different performance guarantees, and is efficient in that each of the servers is work conserving. We then present a practical packet-by-packet service discipline (PGPS) that closely approximates GPS. This allows us to relate results for GPS to the packet-by-packet scheme in a precise manner. The schemes GPS and PGPS were suggested earlier by De-mers, Shenker and Keshav [4] in the context of controlling congestion at network gateway nodes. In this paper, the performance of a single server GPS system is analyzed exactly from the standpoint of worst-case packet delay and burstiness when the sources are constrained by leaky buckets. The worst-case session backlogs are also determined. In the sequel to this paper these results are extended to arbitrary topology networks with multiple nodes