Usually a 4xx class message is what the audible code would map to however since all their term is in-network and bypassing them and sending the call elsewhere yields no such problem it would seem to indicate they are the ones screwing the pooch on those instances. Like I said however these instances aren't all that common but can be a pain when they arise. On Fri, 2009-08-28 at 22:30 -0400, Alex Balashov wrote:
anorexicpoodle wrote:
We use O1 as one of our peers. There is the occasional termination issue where they serve rejection messages in audio without a sip code for us to route advance, on the whole they aren't bad, but nothing really stands out either way.
Are you sure that's them and not a far-end switch?
What kind of rejection is it? Certain kinds of rejections don't get translated to signaling-plane feedback and instead are conveyed via in-band audio message, per de facto SIP<->ISUP convention.