[SR-Users] Proxying INVITE message without port information in R-URI

Alex Balashov abalashov at evaristesys.com
Tue Jan 18 20:46:20 CET 2011

It is assumed 5060 by default.

Alex Balashov - Principal
Evariste Systems LLC
260 Peachtree Street NW
Suite 2200
Atlanta, GA 30303
Tel: +1-678-954-0670
Fax: +1-404-961-1892
Web: http://www.evaristesys.com/

On Jan 18, 2011, at 2:27 PM, Vikram Ragukumar  
<vragukumar at signalogic.com> wrote:

> Hello,
> Alex, Klaus thank you for your replies.
>> Usually the softphones register to the proxy or SIP server. Thus, the
>> proxy or SIP server knows under which IP:port (The IP:port from which
>> the REGISTER was received) it can contact the sofpthone.
> Yes, the softphones are registered to the SIP server, and hence the  
> SIP server has the IP:port information required to contact the  
> softphone. However, the SIP server does not include the port number  
> in the R-URI of the INVITE that it generates.
> This port number is dynamically assigned by the firewall and is not  
> fixed, so manipulating the pseudo variable $rp by assigning it a  
> fixed number will not work.
> If it is not mandatory to include the port number in the R-URI, how  
> does the proxy determine the port to which the SIP message must be  
> forwarded ?
> Thanks and Regards,
> Vikram.

More information about the sr-users mailing list