[AG-TECH] vic fact

Colin Perkins csp at csperkins.org
Tue Nov 18 06:31:04 CST 2003

On Tuesday, Nov 18, 2003, at 09:35 Europe/London, S.Booth wrote:
> One thing to watch out for with firewall configurations like this is 
> that
> they are assuming a
> request/response so if they pass a udp packet in the outward direction
> they will accept incoming packets from the destination host/port for a
> short window afterwards. With RTP data this will only work while all
> parties are transmitting. If one party stops transmitting then a short
> time afterwards the firewall will start blocking the icoming data
> port. The control port will remain open so you will continue to see the
> participants in the status window.

Right. Ideally rat would send a periodic "comfort noise" packet to keep 
the firewall binding open during silent periods.

Colin Perkins

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