Routing metric for connections with reserved bandwidth

摘要

Link state algorithms commonly provide the routing function in computer networks that implement a connectionless network layer. In this paper, we show how such an algorithm can be easily modified to provide the routing function for another type of networks, namely virtual circuit networks with bandwidth reservation. Examples of such networks are those of ST.II routers, or ATM networks. The extension consists of (1) applying the routing function to connection setup requests (instead of to individual packets), (2) defining a new metric that reflects the allocatable capacity available on links and (3) modifying the path computation algorithm. The overall changes to an existing routing protocol implementation are very small. One benefit of the method is that it allows the reuse of well-tested routing code. An additional benefit is that the routes produced by the method are computed ( and stored ) prior to connection requests, thus supporting fast connection setup.