M2PA defines a protocol supporting the transport of SS7 MTP3 signaling messages over IP, using the services of the SCTP. M2PA allows for full MTP3 message-handling and network-management capabilities between any two SS7 nodes communicating over an IP network. M2PA supports:

1. Seamless operation of MTP3 protocol peers over an IP network connection
2. The MTP2/MTP3 interface boundary, management of SCTP transport associations, and traffic instead of MTP2 links
3. Asynchronous reporting of status changes to management

The MTP specification requires that each node with an MTP3 layer will be represented by an SS7 point code. Thus, each IP signaling point must have its own SS7 point code.

Figure 4 depicts an SS7 signaling point connected through an SG equipped with both traditional SS7 and IP network connections to an IP signaling point. The IP signaling point processes MTP3–to–MTP2 primitives. In effect, the SG acts as an STP.

Figure 4.

Another example, related to the above figure, refers to two SGs connected over an IP network to form an SG mated pair similar to the way STPs are provisioned in traditional SS7 networks.

Figure 5 depicts another example. In this example MTP3 is adapted to the SCTP layer using the M2PA in an all–IP architecture.

Figure 5.

Here the IP signaling-points MTP3 uses its underlying M2PA as a replacement for MTP2. Communication between the two layers—MTP3 or M2PA—is defined by the same primitives as in MTP3/MTP2 communication. M2PA performs functions similar to MTP2.