The flow detection protocol design in multiprotocol over ATM

A key to ATM´s success and Internet´s further success will be the ability to allow for interoperation between the existing network technologies and ATM. The MPOA (multiprotocol over ATM) which is presented and standardized by ATM Forum in July 1997, is an efficient solution to the interoperation between ATM and the existing networks. The goal of MPOA is the efficient transfer of inter-subnet unicast data in a LANE (LAN emulation) environment. The edge-device in the network forwards inter-subnet packets to router through a default path at first. When it recognizes that the flow could benefit from a shortcut that bypasses the routed path, it uses a protocol to establish a shortcut to the destination. If a shortcut is available, the edge-device sets up a shortcut virtual channel, and forwards packets to the destination over the shortcut path. However, the MPOA specification has not defined the protocol of flow detection (switching path from the default one to the shortcut one), it is for further study. Actually, the path switching protocol i.e., how to determine whether the flow will benefit from the shortcut path is a key factor determining the efficiency of the MPOA. We present three kinds of solutions to the flow detection protocol