[sipX-dev] Disapearing Record-Route header

["Robert Joly" <rjoly1@xxxxxxxxx>]

Hi,
I have an SipX 3.7.5-008072 located on a private network behind an InGate firewall.  When a registered SIP phone behind an Intertex IX67 tries to access voicemail on SipX via the Ingate, the call fails.  After looking at the logs, it appears that the auth-proxy is doing some 'creative' manipulation of Record-Route headers.  Let me explain:

Setup
=====
IP Phone----->IX67-------->InGate------>SIPX
      (private)   (public)      (private)

Observations
============
* The INVITE that leaves the IX67 contains one RR header pointing at the public IP address of the IX67.  

* InGate adds its own RR header to the INVITE.  INVITE now contains 2 RR headers:
   RR #1 = Private IP address of InGate
   RR #2 = Public IP address of IX67

* SIPX receives the INVITE containing 2 RR but the 200 OK it sends in response to the INVITE contains the following two RR headers:
   RR #1 = IP Address:port of the auth-proxy
   RR #2 = Public IP address of IX67

Surprisingly, the RR header pointing to the InGate private IP Address has been removed by the auth-proxy which results in the call failing.

I could not find any valid reason that would authorize the auth-proxy to take out the RR header of the InGate box (InGate uses distinct and unique user@host parms in RR).  

Has anybody else experienced this problem or has a technical explanation for his phenomenon?

Cheers,
bob