Hello Gaurav, May be your sip client is learning the IP address (NAT) via some mechanism like STUN etc. But I am not sure, why it only does for second REGISTER. May be its designed that way that after learning, during re-REGISTRATIONs it will use the learnt address.
One more interesting point - are you facing any issues with this? May be your organization NAT is SIP aware? Br, Somesh -----Original Message----- From: ext Srivastava, Gaurav [mailto:gaurav.srivast...@inin.com] Sent: Wednesday, June 12, 2013 8:00 AM To: SIP Implementors; discuss...@sipforum.org Subject: [Sip-implementors] Address change in "Via" field from private IP to public IP. Hi, I am using a SIP soft phone (Zopier) that registers to Skype. The softphone sends out a REGISTER message to sip.skype.com for this. While going through the messaging, I noticed that initially the via field contains my private IP address. When the client re REGISTERs, the address changes from my private IP to the public IP which my organization has. Please note that I am running the packet capture on my laptop. I am trying to understand the change in IP address - please let me know if you have an understanding of this. Warm Regards, Gaurav Srivastava. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
