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