Port 2904MTP2 User Adaptation (M2UA)

SIGTRAN protocol that carries MTP2 user signaling over IP, normally using SCTP on port 2904.

transport: tcp · udp · sctp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

also known as MTP2 User Adaptation Layer, SIGTRAN M2UA, RFC 3332

Technical Details

what runs on :2904

M2UA, specified in RFC 3332, adapts SS7 MTP2-user signaling for IP transport without carrying the MTP2 link layer itself. Deployments normally establish an SCTP association on port 2904, then exchange M2UA management messages such as ASP Up and ASP Active before sending DATA messages containing MTP2-user payloads. Messages use a common SIGTRAN header with typed parameters and are framed by the transport association rather than by an application-level byte stream. TCP and UDP are registered transports, but SCTP is the standard deployment choice. Related SIGTRAN services include M3UA on port 2905 and SUA on port 14001.

Security Information

exposure of :2904

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

network services averages 3.1 across 923 ports — this one sits 2.9 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp · sctp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

M2UA is signaling-plane traffic and is not encrypted by default. Internet exposure can permit association exhaustion, denial of service, management-state manipulation, or injection and interception of SS7 signaling if access controls are weak; it should normally be restricted to trusted signaling peers and protected with network filtering and, where appropriate, IPsec or an equivalent secured transport path.

Record

iana registry entry

port: :2904
service: MTP2 User Adaptation (M2UA)
transport: TCPUDPSCTP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: Network Services Voice and Chat
usage: M2UA is used in carrier signaling networks to transport MTP2-user primitives between an application server and a signaling gateway. It is primarily encountered on private SS7/SIGTRAN infrastructure, with SCTP being the normal transport; TCP and UDP are also registered for the service.
lookups: 0rank 994
added: 2026-09-03
updated: 2026-09-03
references: IANA service name registry — port 2904

Something wrong?

This record is maintained by the engineers who use port 2904. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-03.

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risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :2904MTP2 User Adaptation (M2UA)

Technical Details

Security Information

Related Ports

Port 2904MTP2 User Adaptation (M2UA)