A Scalable Virtual Circuit Routing Scheme for ATM Networks

High-speed networks, such as ATM networks, are expected to support diverse quality-of-service (QoS) requirements, including real-time QoS. Real-time QoS is required by many applications such as voice and video. To support such service, routing protocols based on the Virtual Circuit (VC) model have been proposed. However, these protocols do not scale well to large networks in terms of storage and communication overhead. In this paper, we present a scalable VC routing protocol. It is based on the recently proposed viewserver hierarchy, where each viewserver maintains a partial view of the network. By querying these viewservers, a source can obtain a merged view that contains a path to the destination. The source then sends a request packet over this path to setup a real-time VC through resource reservations. The request is blocked if the setup fails. We compare our protocol to a simple approach using simulation. Under this simple approach, a source maintains a full view of the network. In addition to the savings in storage, our results indicate that our protocol performs close to or better than the simple approach in terms of VC carried load and blocking probability over a wide range of real-time workload. (Also cross-referenced as UMIACS-TR-94-115