[Asterisk-Users] Illegal redirection

[Joao Pereira]

Hello
I have two Cisco 7940 phones with private addresses (10.0.11.239 and 
10.0.11.140) connected to Asterisk.
Asterisk is also with private address (10.0.0.135), but in another network.

Between the networks I have a Checkpoint Firewall-1NG
The Cisco IP phones can register because the REGISTER packets arent blocked.
But the INVITEs never reach Asterisk , because the Firewall drops them, 
saying there was an illegal redirection.

The most strange part, is that, when I try to make a phone call from 
PhoneA(10.0.11.239) to PhoneB(10.0.11.240), the INVITE is dropped before 
reaching Asterisk, and it says "Illegal redirection 
10.0.0.135->10.0.11.240". How can the firewall know that the INVITE was 
going to be redirected by Asterisk to PhoneB(10.0.11.240) ????

Joao Pereira