SIP and VIAs - Voice Over IP

[jkmathew77]

Anyone konw if this is a configuration eorror or a PIX bug. We are trying to get SIP messages in and out the firewall.

It turns out that it is indeed a PIX problem. All of the Vias have IP addresses before the PIX. After the PIX they are all stripped out. The PIX should probably strip the addresses to hide the details of the network inside the PIX, but it should put something in to replace the original IP addresses so that the Vias are still syntactically correct.

Perhaps this is a configuration problem? Maybe the token
or address that it is suppose to substitute is something that needs to be configured and is blank by default?

Anyone have any idea?

 

[yizhar]

HI.

What pix version?
Pix version 6.21 and above fix some SIP bugs.

Are the SIP hosts using PAT,NAT or STATIC?

What port are you using? Is should match the pix fixup command.

You should configure the SIP hosts to use their own internal ip address as the "reply" address, not the external ip address of your network.
The pix should convert it as needed when the packet goes through it.

Use the following to get more info:
* PIX syslog messages.
* debug sip ...
* A network monitor.

It can be usefull to open a TAC or contact Cisco in some way for assistant. Check also the forums of cisco web site:

http://forum.cisco.com/eforum/servlet/NetProf?page=main

Bye
Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar