# Overview

Mumble is based on a standard server-client communication model. It
utilizes two channels of communication, the first one is a TCP connection
which is used to reliably transfer control data between the client and the
server. The second one is a UDP connection which is used for
low latency transfer of voice data.

![Mumble system overview](resources/mumble_system_overview.png)

Both are protected by strong cryptography. This encryption is mandatory and cannot be disabled. The TCP control channel uses TLSv1 AES256-SHA[^1] while the voice channel is encrypted with OCB-AES128[^2].

![Mumble crypt types](resources/mumble_crypt_types.png)

While the TCP connection is mandatory the UDP connection can be compensated by tunnelling the UDP packets through the TCP connection as described in the protocol description later.

[^1]: <http://en.wikipedia.org/wiki/Transport_Layer_Security>
[^2]: <http://www.cs.ucdavis.edu/~rogaway/ocb/ocb-back.htm>