# What is M3UA?

> M3UA (MTP Level 3 User Adaptation) is a SIGTRAN protocol that carries SS7 MTP3-user signaling — SCCP and ISUP — over IP using SCTP, letting legacy SS7 applications run across modern IP networks without TDM links. It is the transport most operators use to reach SS7/MAP peers today, and the layer an SS7 signaling firewall inspects. See /answers/what-is-sigtran, /answers/sigtran-adaptation-layers, and /answers/what-is-sccp.

- Canonical URL: https://www.broadnet.me/answers/what-is-m3ua
- Language: en
- Last reviewed: 2026-07-22
- Publisher: BroadNet (https://www.broadnet.me)

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [SIGTRAN — SS7 over IP explained](https://www.broadnet.me/answers/what-is-sigtran)
- [SIGTRAN adaptation layers — M3UA, M2UA, SUA explained](https://www.broadnet.me/answers/sigtran-adaptation-layers)
- [What is SCCP?](https://www.broadnet.me/answers/what-is-sccp)
- [What is SS7?](https://www.broadnet.me/answers/what-is-ss7)
- [SS7 Firewall](https://www.broadnet.me/operators/ss7-firewall)
- [Signaling & CDR Intelligence](https://www.broadnet.me/platforms/signaling-cdr)