Mumble ports and firewall explained

The basics

Mumble's default port is 64738. It uses that same port number for two kinds of traffic:

• TCP carries the connection, login and text chat.
• UDP carries the voice.

Voice sounds best over UDP. If UDP is blocked, Mumble falls back to sending voice over TCP. It still works but adds delay, and some players hear it as lag.

Your PlayNHost server uses a different port

Each server gets its own port, so the number on your Overview page is not 64738. Always enter the address and the port shown there. Nothing on your side needs opening for a client to reach it: a normal home router lets outgoing connections through.

When a player cannot connect

1. Check the address and port were typed exactly: Cannot connect to your Mumble server: fixes.
2. School, work and some mobile networks block unusual ports. Test on another network.
3. A VPN can block UDP or change the route. Turn it off to test.
4. Some firewalls and antivirus tools ask whether to allow Mumble the first time. Allow it on private and public networks.

When voice is delayed but connected

The player's network is dropping UDP. In Mumble open Configure, Settings, Network and check Force TCP mode is off. If it stays slow, try another network.

For people who run their own server

A server you run yourself at home needs the port forwarded for both TCP and UDP to the machine running Mumble, and an allow rule in its firewall. With a hosted server none of this is your job.

See also How to improve Mumble voice quality.