I agree with Robert. But if you deal with some super tricked protocols (like SpyPE) and you really want to block VoIP (not show that you comply to regulations, but REALLY block it) - disruption looks as the only real opportunity. For any filterig, I can always create a protocol which will ignore your filters. ----- Original Message ----- From: "Robert Mathews" <mathews@hawaii.edu> To: "NANOG" <nanog@merit.edu> Sent: Saturday, November 13, 2004 11:12 AM Subject: Re: How to Blocking VoIP ( H.323) ?
On Fri, 12 Nov 2004, Alexei Roudnev wrote:
Date: Fri, 12 Nov 2004 09:46:15 -0800 From: Alexei Roudnev <alex@relcom.net> To: Robert Mathews <mathews@hawaii.edu>, NANOG <nanog@merit.edu> Subject: Re: How to Blocking VoIP ( H.323) ?
Alexei:
How exactly then would anyone implement this, without screwing-up the overall performance elements in the network? :)
Not too easy, but I can imagine few alghoritms doing it. Remember that
VoIP
uses short packets, and you cam always recognize Ack and Tcp packets which should not be disrupted. Jitter does not slow down network, except if it interacts with RTT calculartion in TCP/IP.
Alexei:
Apologize for the delay in getting a reply to you.
Regarding your comment on jitter, FLATLY or more generally, if introducing jitter is likely to complicate operational matters elsewhere in the network [whether this complication manifests within one's own network or in another - to which one is inter-connected] I would be inclined to say this effects the overall performance...
I did not mean to take more of your time on this. But, I wanted to merely clarify.
Best, Robert. -------