[Serusers] Simple proxy

[Arnd Vehling]

Hi,

look at the howto link at http://iptel.org/ser.

For securing the cisco you only need to filter the sip port
(usually 5060) with an cisco access list. You dont need to
filter rtp/udp/voice streams because no one can setup a
voice stream without sending an SIP INVITE to the cisco.

This only true if you use a sip-proxy off course and dont let
the sip-UAs connect directly to your PSTN GW.

regards,

   Arnd