ALPEN: an ATM multi-protocol emulation network, based on periodical performance check between edge nodes

Proposes ALPEN, an ATM-WAN architecture that can emulate multiple ATM-layer protocols such as available bit rate, fast resource management, and short hold mode, using a simple ATM transit network. ALPEN is a flexible network. With ALPEN, it is easy to implement any new ATM-layer protocol by modifying only the edge nodes. ATM-layer protocols are emulated only at ALPEN's edge nodes and the transit network is independent of the ATM-layer protocols. ALPEN has a very short response time. Edge nodes are directly responsible for the management of the users' bandwidth, eliminating the long round trip delays of conventional networks. A simple and high-speed ATM transit network periodically reports to the edge nodes the performance of the transit network's routes using cyclic periodical route performance check (PRPC) cells. PRPC cells are independent of the ATM-layer protocols. Their information is used by the edge nodes to manage the users cell rates in real time. ALPEN is also a simple architecture. The transit network does not support multi ATM-layer protocols; only the PRPC protocol. ALPEN's transit switches do not need large computational power: performance checking is performed per route and not per virtual circuit as in conventional networks. ALPEN is a cost effective architecture. Flexible, adaptive and sophisticated protocols for an efficient use of resources can be easily supported by the network's edge node. Users can then send as much traffic as permitted by the network's available bandwidth. The ALPEN architecture introduced in this paper is an efficient approach to implementing multimedia, multi-protocol ATM services in an ATM-WAN.