M2PA

M2PA, short for MTP2 User Adaptation, is a SIGTRAN protocol that enables the transport of MTP2-level SS7 signaling messages over IP networks. It provides framing, sequencing, and error-handling mechanisms to carry MTP2 data units across an SCTP-based transport between STPs or signaling gateways.

Operating as an adaptation layer between the MTP2 layer of the SS7 stack and the IP transport, M2PA relies on SCTP for reliable, in-order delivery, with support for features such as multi-homing and congestion control. It handles MTP2 link status and link-set events to reflect the state of remote SS7 links and maps MTP2 signaling frames into M2PA messages and back at the receiving end.

M2PA is one of several SIGTRAN adaptation layers designed to carry SS7 signaling over IP. In particular, it sits alongside M3UA, which carries MTP3-level signaling, and M2UA, which transports MTP2 events to MTP3-using applications. Together, M2PA, M2UA, and M3UA enable SS7 signaling over IP networks for telecom signaling, VoIP, and broadband services.

Deployment typically involves signaling gateways, STPs, and softswitches that interconnect traditional SS7 networks over an IP backbone. M2PA-enabled networks benefit from SCTP features such as reliable transport and multi-streaming while preserving SS7 signaling semantics at the MTP2 layer.