[Asterisk-Users] PIX!!!!!

[brett-asterisk at worldcall.net]

Christopher wrote:

> Thanks guys, really appreciate the responses. 
>
> Actually I've tried the suggestions in this document with absolutely 
> no luck at all unfortunately, and turning off fixup protocol udp sip 
> was the key to allowing my remote phone to ring to an internal phone 
> (when fixup is on I can see the remote phone, but it will not ring the 
> internal phones).  But no matter what the fixup featured is set to * 
> still shows that phone as "Unreachable" and the port number as 0.


Hey Chris,
My setup is that Asterisk is on a public IP and the customer is using 
private IPs behind a Cisco PIX.

When we first has the sip fixup enabled, it worked just as you 
described. I think what what happening is as follows:
1. Phones are configured for NAT
2. Cisco PIX "handles NAT" by rewriting headers so the phone doesn't 
appear to be NATted (for SIP proxies that may not support natted devices)
3. Asterisk was expecting NAT headers because of nat=yes

So I left nat=yes and recommended turning sip fixup off. That seemed to 
work for us.

I suppose (and I'd like to try this in my lab) that perhaps setting nat 
to no or never and having the nat fixup could be an interesting test as 
well.. Does anyone out there have any experience with this?
-Brett