[asterisk-users] SIP reply CALL-ID from ITSP has internal address in host part

[Olle E. Johansson]

10 sep 2009 kl. 17.35 skrev Alex Balashov:

> Andrew Stewart wrote:
>
>> Figured out the problem.  There is an "inspect sip" command in our
>> global policy map on our Cisco ASA firewall.  That was "fixing" the
>> CALL-ID.  Took it out and all is working now.
>
> Ah, yes.  Those ALGs (or other >= Layer 5 manglers, whatever the
> justification) will always get you.  :-)  I was pouring over the  
> capture
> you provided, thinking, "This really doesn't add up..."

You were lucky that you could disable it. I've met cases where  
firewalls have a smart SIP something feature that can't be disabled  
and enabled it was successful in disabling all media stream by  
publishing RFC1918 addresses on the outside.

Ouch.

/O