Port 2945: H.248/Megaco Binary — The Binary Half of a Telecom Protocol Pair

Port 2945 has no official IANA service assignment, but in telecom infrastructure it has a clear, stable identity: it's the binary half of a protocol pair.

The Protocol Pair

Ports 2944 and 2945 travel together. They both carry H.248/Megaco — the Media Gateway Control Protocol — a signaling protocol used to control the gateways that translate between VoIP and the traditional public switched telephone network (PSTN). ¹

The difference between the two ports is encoding:

• Port 2944 — H.248/Megaco in text format. Human-readable. Easier to debug.
• Port 2945 — H.248/Megaco in binary (ASN.1) format. Compact. Efficient. Used in 2G/3G core networks where bandwidth and speed matter. ²

Same protocol. Two representations. Two ports.

What H.248/Megaco Actually Does

When you make a VoIP call that reaches someone on a regular landline, something has to translate between the IP world and the circuit-switched phone world. That something is a Media Gateway (MG). The protocol that tells the gateway what to do — when to connect, when to disconnect, how to handle the media stream — is H.248/Megaco.

A Media Gateway Controller (MGC) sits above the gateway and sends it instructions. Port 2945 is where those instructions arrive, in compact binary form. ³

It's infrastructure that most people never think about, running quietly beneath every call that crosses the boundary between the Internet and the phone system.

The Port Range

Port 2945 sits in the registered port range (1024–49151). These ports are tracked by IANA, but unlike the well-known ports (0–1023), they don't require privileged access to bind, and IANA registration is not mandatory for use. Many ports in this range have de facto uses that predate or bypass formal registration. ⁴

Port 2945 is a good example: widely used in telecom equipment for H.248 binary signaling, documented across vendor implementations and Wireshark dissectors, but not formally registered under a service name.

Who Uses This Port

You're unlikely to encounter port 2945 on a typical enterprise or home network. It appears in:

• Telecom carrier infrastructure
• VoIP gateway deployments
• Legacy 2G/3G core network nodes
• Lab environments testing PSTN integration

If you see it open on a general-purpose server, investigate.

What's Listening on This Port

To check what process is bound to port 2945 on your system:

Linux/macOS:

# Show the process listening on port 2945
ss -tlnp | grep 2945
# or
lsof -i :2945

Windows:

netstat -ano | findstr :2945
# Then match the PID in Task Manager, or:
Get-Process -Id (Get-NetTCPConnection -LocalPort 2945).OwningProcess

If nothing shows up, nothing is listening. That's the expected result on most machines.