M2UA defines a protocol for transport of SS7 MTP2 user (e.g. MTP3) signaling messages over IP using SCTP. The only SS7 MTP2 user is MTP3. M2UA provides support for:

• MTP2/MTP3 interface boundary
• Communication between layer-management modules
• Support for management of active associations

Figure 6. Connection of SG to IP Signaling Point

In an SG, it is expected that the SS7 signaling is received over a standard SS7 network termination, using the SS7 MTP to provide transport of SS7 signaling messages to and from an SS7 signaling endpoint. The SG then provides interworking of transport functions with IP SIGTRAN in order to transport the MTP3 signaling messages to the IP signaling point where the peer MTP3 protocol layer exists. In M2UA, the IP signaling point's MTP3 uses the SG's MTP2 as its lower SS7 layer using the appropriate primitives defined between the layers. The MTP3/MTP2 communication is defined as M2UA messages and sent over the IP connection.