Analysis of the Increase and decrease Algorithms for Congestion Avoidance in Computer Networks Dah-Ming CHIU and Raj jAl 1. Introduction Digital Equipment Corporarion, 550 King Siree(LKGI-2/4A19 Littleton, MA O1460-1289, U.S.A 1. background Congestion in computer networks is becoming an important issue due to the increasing mismatch in link new technology, Recent technological advances that allow the network to recover from the congested state of high delay and low throughput. Both con gestion avoidance and congestion control mechanisms are basi ally resource management problems. They can be formulated algorithm(or control function) used by ease or decrease their load (window or rate). We abstractly aFro 979 to 1980. he was wi de class of such increase/decrease algorithms orked on applying queuing theory to and compare them using several different performance metrics. Thcy kcy metrics are cfficicncy, fairncao, convcrgence time, been with Digital Equipment Corpo- and size of oscillations. formance modeling and analysis of com It is shown that a simple additive increase and multiplicative decrease algorithm satisfies the sufficient conditions for con- tems Archi to an efficient and fair state regardless of the starting rithms. His research interests include operation systems, dis- ation in the congestion avoidance scheme recom- and optimization theories. Digital Networking Architecture and OSI Trans- Dr Chiu is a member of the ACm and the IEEE ort Class 4 Networks Raj Jain received the B.E. degree eywords, Computer Network, Congestion ctor oL, Congestion AvO dance. flow Control fairness. cambridgeoma. in19⊥ His Ph D. dissertation their"Outstanding dissertations in systems and networks including VAX Clusters, DECnet, and rchitecture and perfe a sabbatical at the ma cal area systems. For North-Holland Computer Networks and ISDN Systems 17(1989)1-14 er of the Association for Computing Machinery. and a senior member of IEEE 0169-7552/89/S3.500 1989, Elsevier Science Publishers B V(North-Holland)