Call of Duty data compression

Hello everyone.
I was thinking on how does call of duty (1,UO,2,4) communicate over the internet, and i came across on some
kind of "data compression". I was told that it's "huffman coding". So okey, quick google search and i found on
wikipedia about "huffman tree". It works by making more common characters weight less and opposite (if i
got it right). So if that is true, how is it sent over to the server by a client and the other way around ?
You will need a character frequency and by the way, all code is in binary.

So, simple question. How to compress CoD client data to server-readable data ?

An introduction to the Quake 3 Networking model:

http://trac.bookofhook.com/bookofhoo...ake3Networking