If you already use Mumble and just need the server info, it is as follows.

Server: mumble-us.cleanvoice.com

Port: 38709

Mumble is an open source, low-latency, high quality voice chat software primarily intended for use while gaming.

Because of the low latency, audio options, and lightweight client. It's also very easy to use.

Please download the latest version from the page at this link.

Please use the instructions from this page.

Here's some information that's easy to figure out and doesn't seem to be in the main mumble wiki…