AS Egress Selection Optimization Based On Link States

This paper presents an optimization mechanism to facilitate efficient selection of BGP egress for an AS, when IGP link state changes. Most mechanisms for BGP egress selection have primarily focused on achieving an optimized goal by considering it as a static problem, which leads to inflexibility to variations in the topology of an AS, especially for link failures which often occur in an AS network. Our mechanism provides a flexible means for an AS to optimize routing according to their multiple goals. Based on precomputed control rules and current link state, every BGP router can select appropriate egress points by itself. The mechanism is extensible, flexible, and robust. A critical algorithm based on link states is applied to illustrate the main idea of the mechanism. Simulation results demonstrate that our solution is feasible and expressive for the network administrators.