MPOA (MultiProtocol Over ATM) is a protocol developed by the ATM Forum. More complex than NHRP he uses the techniques described in the previous sections by uniting and complementing to achieve IP packet transport or other protocol packets, such as IPX, over an ATM network interconnection. The road can be determined either by a centralized route server solution type, either by a distributed solution using the PNNI or NHRP protocols.
The role of MPOA is always to find the corresponding ATM address to open a direct connection, or shortcut, between two ATM stations that know at the outset that by their IP address.
The two components of MPOA are:
• MPC (MPOA Client), which, at the request of a client, research the best way to open a virtual circuit with a customer who knows the IP address.
• MPS (MPOA Server) located in a router, which, using a conventional routing, such as RIP (Routing Information Protocol), OSPF (Open Shortest Path First), etc., routes NHRP query requests correspondence.
Figure shows how MPOA. Phase 1 is the address conversion request dating back to the MPS server knowing the answer. Phase 2 conveys the response to the conversion request which allows the opening of the virtual circuit to the remote.