Iterative Discovery of Multiple Disjoint Paths in Switched Networks with Multicast Frames

Abstract

Routing via multiple paths offers many advantages such as traffic separation, congestion reduction and quality of service policies in enterprise, campus and data center networks. Disjointness of the multiple paths may provide extra benefits like increased reliability and improved traffic separation. We propose DMDP, a layer two protocol that discovers multiple disjoint paths in a switched network by exploration of the network with multicast frames. DMDP provides fast discovery of node-disjoint or link-disjoint paths, selecting the fastest disjoint paths available without any route computation over the network graph. Paths obtained by DMDP are similar to the multiple paths computed with a k-shortest path algorithm, but much simpler to find. Multiple disjoint path search may be implemented as a proactive, reactive on-demand or hybrid service at edge switches.