[VoiceOps] SIP 404 Not Found vs 603 Decline

Alex Balashov abalashov at evaristesys.com
Wed Jun 3 15:24:05 EDT 2015


487 is normally expected only for scenarios in which the INVITE 
transaction has been terminated due to a CANCEL'd branch. 3261 says:

    The request was terminated by a BYE or CANCEL request.  This
    response is never returned for a CANCEL request itself.

So, it's not an appropriate final negative response to send when not 
commanded by a CANCEL. I recommend 503 Service Unavailable.

-- Alex

-- 
Alex Balashov | Principal | Evariste Systems LLC
303 Perimeter Center North, Suite 300
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United States

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