End 2 end CANCEL Reason (and other additional CANCEL headers)

[ThomasSevestre]

This is a solution to #164

Please, be aware...

I've not tested the PR on master but it is working on an older version of sems.
I've used this with SBC application only.
It would be better to pass Reason header only.

[juha-h]

Is relaying of CANCEL headers configurable in sbc profile?

[ThomasSevestre]

Not in this PR.

First it could be a good idea to make sure this is triggered only in SBC module, we need to override onCancel in CallLeg (see here)

This looks simple, I can do it.

CallLeg does not have direct access to profiles, it requires more work to make this configurable. Relaying CANCEL Reason header looks like something that should be done by default.

[hecko]

@ThomasSevestre do you think we should revisit this PR - is it still something you would like to add into SEMS in its current proposed PR?

[ThomasSevestre]

@hecko,

I beleive E2E Cancel Reason is an important features. I've used the proposed PR for years without issue in my setup.

Current implementation has a few limitations :

• passes all headers (not only the Reason header) It would be safer to pass only the Reason header.
• as @juha-h mentionned, it could also be interesting to add a configuration parameter to enable this functionality.
• If I remember well I was thinking to to move the following change in SBC application :

void AmB2BCallerSession::onCancel(const AmSipRequest& req)
{
  terminateOtherLeg();
  terminateOtherLeg(req.hdrs);
  terminateLeg();
}

I do not have easy access to sems anymore to work on this PR.

Feel free to take over (or to close the PR if you prefer)

thanks for your work on sems

[hecko]

This has been re-implemented into SBC application in #369 - thanks for the suggestion and feedback @ThomasSevestre