Hierarchical Routing for Very Large Networks

This paper presents a hierarchical routing design undergoing implementation for the Survivable Packet Radio network project (SURAN) under the auspices of The Defense Advanced Research Project Agency. As in the previous Packet Radio network, this network is built on a carrier sense, multiple access broadcast channel and is populated with mobile store and forward nodes known as packet radio units, or PRs. The goals of SURAN are to create a large distributed network of 1,000 to 10,000 nodes with a redundant, fluid control structure that is capable of surviving the loss of components and other more active threats against the network control structure. Key to the success of this network are name servers which relate the current location of a device to a network address, access controllers which curtail network membership and privileges, network monitors which report on the control structure and network behavior and, finally, super*clusterheads which are responsible for the distributed routing control. The super*clusterheads create hierarchical addresses for each PR and compute the best routes between clusters at each level. This paper discusses issues associated with clustering: membership definition, route creation, distribution and change.