A class of end-to-end congestion control algorithms for the Internet

We formulate end-to-end congestion control as a global optimization problem. Based on this formulation, a class of minimum cost flow control (MCFC) algorithms for adjusting session rates or window sizes is proposed. Significantly, we show that these algorithms can be implemented at the transport layer of an IP network and can provide certain fairness properties and user priority options without requiring non-FIFO switches. Two algorithm versions are discussed. A coarse version is geared towards implementation in the current Internet, relying on the end-to-end packet loss observations as an indication of congestion. A more complete version anticipates an Internet where sessions can solicit explicit congestion information through a concise probing mechanism. We show that TCP congestion control, after some modification, may be treated as a special case of the MCFC algorithms.