Switch Scheduling via Randomized Edge Coloring

The essence of an Internet router is an n ¡ n switch which routes packets from input to output ports. Such a switch can be viewed as a bipartite graph with the input and output ports as the two vertex sets. Packets arriving at input port i and destined for output port j can be modeled as an edge from i to j. Current switch scheduling algorithms view the routing of packets at each time step as a selection of a bipartite matching. We take the view that the switch scheduling problem across a sequence of time-steps is an instance of the edge coloring problem for a bipartite multigraph. Implementation considerations lead us to seek edge coloring algorithms for bipartite multigraphs that are fast, decentralized, and online. We present a randomized algorithm which has the desired properties, and uses only a near-optimal ∆ ¢ o£ ∆¤ colors on dense bipartite graphs arising in the context of switch scheduling. This algorithm extends to nonbipartite graphs as well. It leads to a novel swi...

• Type: Conference
• Year: 2003
• Where: FOCS
• Authors: Gagan Aggarwal, Rajeev Motwani, Devavrat Shah, An Zhu
• Keywords: FOCS 2003, Output Port, Switch Scheduling, Switch Scheduling Algorithm, Theoretical Computer Science