(MultiProtocol Over ATM) An ATM Forum standard that provides routing of legacy protocols (IP, IPX, etc.) over ATM networks. MPOA separates the routing processing from the actual forwarding. A route server performs the routing calculations and sends its results to the ATM switches and edge devices which perform high-speed forwarding of the packets. Before MPOA, LAN emulation (LANE) required a router to communicate between subnets. See virtual routing, I-PNNI and LANE.
A specification (July 1997) from the ATM Forum (now merged into the MFA Forum) designed to enhance LAN Emulation (LANE) by enabling interELAN communications without the intervention of a router, and the associated packet delay. MPOA provides high-performance, scalable routing functionality over an ATM platform, expanding on LANE, Classical IP over ATM (RFC 1577), and the IETF's Next Hop Resolution Protocol (NHRP) in order to create a standardized notion of a virtual router within an ATM network. See also ATM, ATM Forum, Classical IP over ATM, ELAN, IETF, LANE, MFA Forum, NHRP, packet, router, and virtual.