QoS-based connection set-up in ATM networks

It is possible to set up virtual connections across multiple ATM switches using ATM Forum's Private Network-Network Interface (PNNI). However, the PNNI protocol is a complex signalling protocol. Although PNNI supports QoS routing, current ATM switches may not fully implement QoS routing as in the PNNI specification. This paper describes a system for creating virtual connections based on QoS requirements, thus providing basic QoS routing functionality. The system maintains up-to-date link-state information in a centralised database, and distributes system tasks such as connection set-up, QoS route selection and detection of link failures, to a few subsystems in a scalable manner. It effectively bridges the gap between complex protocols like PNNI and tedious manual set-up of virtual connections, and can be useful in managing wide area ATM networks such as SingAREN, SingaporeONE and the vBNS.