Stability of a Class of Dynamic Routing Protocols (IGRP)

We perform an exact analysis of the dynamic behavior of IGRP, an adaptive shortest-path routing algorithm widely used in the industry, on a simple ring network. The distance metric is a weighted sum of traficsensitive and trafic-insensitive delay components. We relate the optimality and stability of the protocol to the ratio of the weights. In particular, we show that if the trafic-insensitive component is not given enough weight, then starting from any initial routing, the subsequent routings aflerfinitely many update periods will oscillate between two worst cases. Otherwise, the successive routings will converge to the unique equilibrium routing. We also show that load sharing among routes whose distances are within a threshold of the min.inium distance help stabilize the dynamic behavior.

• Type: Conference
• Year: 1993
• Where: INFOCOM
• Authors: Steven H. Low, Pravin Varaiya
• Keywords: Adaptive Shortest-path Routing, Communications, Dynamic Behavior, INFOCOM 1993, Trafic-insensitive Delay Components