[SR-Users] Access to CANCEL messages sent during parallel forking

[Marco Capetta]

Hi All,

I have a question regarding call forking and how to access failed 
branches: the ones for which kamailio sends out the CANCEL because on 
another one a 200OK was received.
This is the scenario:
  - A calls B
  - 3 devices are registered on B, so a parallel forking is done to B1, 
B2 and B3
  - B1, B2, and B3 all reply with 180 Ringing
  - B1 replies with 200OK
  - Kamailio CANCELs the branches with B2 and B3

What I need is access to each single CANCEL that Kamailio sends out to 
B2 and B3.
In particular I need to know the branch-id and Via branch of all the 
cancelled branches. Additionally it would be perfect to have them inside 
the TM module, in order to have access also to internal AVPs.

I tried with dedicated failure routes and also with per-branch failure 
routes, but I was never able to access to those values.
I also didn't found a specific event-route that can help me solve this 
problem.

Does anyone have an idea?

Kamailio version 5.2.5


Thanks

Regards
Marco