SIP Reason: avaya-action

[azapateroalo]

Hello,
I've been chasing a reported issue from a customer, that happens from ti, me to time: whenever a calls is put "on hold", a header reading


Reason: avaya-action;cause=1;text="Hold"


is sent on the SIP Invite request (reinvite).


The calls is hang up on the SP side, as far as that header is not RFC-compliant.


Does anybody knows where this header is being inserted? SM is discarded, also the ASBCE, and I'm pretty sure that this message is a default one from Avaya (not customized).


Regards.

[jwaber]

The use of the "REASON" header is not defined in the foundational SIP standard RFC3261. Instead, it is defined in RFC 3326, and is therefore a standard that a carrier can choose not to support. Ideally, the carrier would ignore a header it does not support, but it appears this one has decided to reject the entire request.

The REASON header can indicate that a call is being put on HOLD because the call is about to be conferenced, transferred, or simply put on hold.

Avaya chooses to use a re-INVITE to change something about an existing call because that conforms to the foundational RFC3261, and therefore is nearly guaranteed to work. Other vendors use an UPDATE for the same purpose, but that request method is not defined in RFC 3261 (it is defined in RFC 3311) and so might not be supported universally.

I believe the REASON header is injected by Communication Manager. I am not aware of any way to disable its inclusion from within CM.

The header can be removed in Session Manager, and in a Session Border Controller. Between the two, I suggest removing it in the SBC just before sending the request to the carrier.