[CentOS] Blocking radio streaming

Thu May 3 22:26:18 UTC 2007
Florin Andrei <florin at andrei.myip.org>

Mário Gamito wrote:
> 
> I've been noticing that many people spend the whole day hearing to 
> online radios.
> 
> How can i block the streaming ?

This is the kind of issue best solved by a notice from management saying 
"thou shall not listen to internet radios at the office, or else".
Then just monitor the network for violators.

Purely technical solutions are not very good. You can block certain user 
agents in a proxy or via a Network IPS, block certain MIME types or file 
types (again, either a proxy or an NIPS can do that), drop HTTP sessions 
that are longer than say 5 minutes (at the firewall or NIPS, and yes, 
drop sessions even if they are active - bad idea sometimes but it will 
greatly annoy the streaming radio users) and add a temporary denial for 
that source/destination IP pair, do traffic shaping to limit the 
bandwidth available to streaming content (at the firewall or router), etc.
In general, a smart NIPS can help you somewhat.
But nothing is perfect and people are likely to be smarter than a piece 
of hardware.

One more idea: if most of them listen to the same radio station, just 
install a streaming proxy (or relay) on the internal network and then 
you can have a lot of internal users connected to the same proxy 
(relay), all of them using essentially just one stream to the outside.
E.g., look at option -r with streamripper:

http://streamripper.sourceforge.net/tutorialconsole.php

Heck, even if two or three stations are the most popular, stream them 
all to an internal relay and tell everyone to use the relay. It's better 
to have just two or three streams, instead of twenty, the users are 
happy, everyone wins.

-- 
Florin Andrei

http://florin.myip.org/