Record-Route and received/rport parameters - sr-users

3 May 2018

Hi All,

I've come accros a scenario where a proxy is sitting on a private 
address range and inserts a record-route specifying the the private address.

This causes issues whereby the BYE to an INVITE attempts to relay to the 
private address defined in record-route.

I was wondering, if we were inject a received and rport parameter into 
the record-route header of the original invite, whould kamailio relay 
the response (BYE) to the receive/rport destination instead of the uri 
defined in the record-route header.

As an example, initial invite comes in with a record-route as follows:

Record-Route: <sip:172.17.0.2:5062;lr;ftag=b4551d29>

If we injected received and rport as follows:

Record-Route: 
<sip:172.17.0.2:5062;lr;ftag=b4551d29;rport=33429;received=212.172.2.212>

and relayed the message to the B2B.

Then, I assume, when the B2B creates its BYE message, the Route header 
should look like this:

Route: 
<sip:172.17.0.2:5062;lr;ftag=b4551d29;rport=33429;received=212.172.2.212>

Once this hits the kamailio instance to relay to the last route header 
as mentioned above, would it set $du to received:rport like it does with 
Via headers?

Thanks