[asterisk-users] Networking Concept

[Gordon Henderson]

On Tue, 6 Oct 2009, Faraz Khan wrote:

> In pakistan they have protocol scanners mounted on all the 4 fibers that
> enter and leave pakistan. They can detect VOIP usage by upload/download
> patterns / etc. They have invaded and arrested many illegal 'calling
> card' operators in the past. Im sure the same is true for china. However
> I dont know how they can detect VOIP traffic in a encrypted tunnel.

50 small (160 byte) packets per second each way per call is still the same 
in an encrypted tunnel... no need to see (DPI) the data, just count the 
packet rate.

Gordon