Suppose there are two parallel bridged legs. Using python application in an extension, I append "X-TO-LB:1" for the first one and "X-TO-LB:2" for the second one. I "mod_distribute" the INVITEs to my SIP server core that knows to dispatch to balancers based on that header value. Next, suppose leg 1 answers and leg 2 gets CANCELed. I need that CANCEL to also contain "X-TO-LB:2" in order to be dispatched to its destination(right now the CANCELed endpoint still keeps ringing because the CANCEL does not have that header).
Note: "X-TO-LB:" is not for balancing purpose but for identifying the balancer responsible for the bridged leg.
I want to do it like this in order not to keep the LB<->ENDPOINT mapping in my python script as long as the SIP core knows to do the dispatching.