Traffic load balancing in a multi-connect topology

Abstract

A technique for load balancing in a multi-topology network selects a network path having a favorable bandwidth*hop count product. Accordingly, shorter paths are prioritized while longer paths are used for traffic load balancing when appropriate. For example, a telecommunications network may employ a Clos-style topology in which hosts are connected to each other through multiple hierarchical levels of forwarding devices. One or more high level switches may be removed, creating isolated blocks of forwarding devices. The blocks may be connected by the remaining original high level Clos-style topology switch(es) and a second type of network topology. In an exemplary embodiment, traffic may be scheduled over routes with the following decreasing priorities: (1) the shortest path, using either or both network topologies; (2) a path using only a single network topology type; (3) non-shortest paths between directly-connected blocks; and (4) non-shortest paths between indirectly-connected blocks.