Load profiling for efficient route selection in multi-class networks

High-speed networks, such as ATM networks, are expected to support real-time Quality of Service (QoS) guarantees required by many applications such as those that involve voice and video communication. To support such services, routing algorithms that allow for the reservation of the needed bandwidth over a Virtual Circuit (VC) have been proposed. Commonly, these algorithms assign VCs to routes using the least-loaded concept, and thus result in balancing the load over the set of all candidate routes. In this paper, we show that for such reservation-based VC routing algorithms-which allow for the exclusive use of a preset fraction of a resource's bandwidth for an extended period of time-load balancing is not desirable as it results in resource fragmentation, which adversely affects the likelihood of accepting new VC requests. We present an on-line VC routing scheme that is based on the concept of "load profiling", which allows a distribution of "available" bandwidth across a set of candidate routes to match the characteristics of incoming VC QoS requests. We show the effectiveness of our load-profiling approach when compared to traditional load-balancing and load-packing VC routing schemes.