M3UA
MTP Level 3 User Adaptation Layer
M3UA enables the transport of SS7 (Signalling System number 7) signalling over IP using the services of SCTP (Stream Control Transmission Protocol). There are various User Adaptation layers available, the choice of which is determined by how much SS7 functionality (in terms of layers) needs to be retained in the IP transport network. Options include SUA (SCCP User Adaptation), M3UA (MTP3 User Adaptation), M2UA (MTP2 User Adaptation) and M2PA (MTP2 Peer to Peer Adaptation).