[cisco-voip] loop start FXO disconnecting from Unity

[Robert]

I will be opening a TAC SR on this issue later today when I can be
available to answer the phone, but I thought I might first bounce the
issue off this brain trust....

I have a location with three loop start POTS lines connected to a 2811
( IOS 12.4(13r)T ) with a VIC2-4FXO card. The lines handle incoming and
outgoing calls without incident except that an incoming call transferred
to Unity will disconnect after a fairly short time. It's difficult to
accurately time the disconnections, but according to CDRs, they are
anywhere from 12 to 19 seconds, but perhaps more importantly, CDR shows
all with a disconnect cause code of 41 (Temporary Failure).

Only FXO incoming calls from this particular gateway transferred to
Unity exhibit this symptom. Incoming calls transferred anywhere else
except Unity work fine. I have 23 other similarly equipped locations
that do not do this. This is a new location put online only last week,
so I really suspect it's a basic configuration issue with the gateway,
except that so far as I can detect, there are no voice port
configuration differences between this one and the others. Obviously,
that can't be true, but that's what I see so far.

Any ideas for something specific to check?

Thanks,

Robert