[cisco-nas] MICA disconnect reason 0xDF06 while connected

[Aaron Leonard]

> > This just means that we got a hangup signal from the TDM network for
> > that call.  (For example, if you're using ISDN, this would be
> > receipt of a Q.931 DISCONNECT.)
> >
> > If the user at the other end of the circuit INTENDED to hang up,
> > then of course this is not a problem.  If he did NOT intend to
> > hang up, then this is a problem.
> >
> > Such a problem could be caused by poor circuit quality and/or by
> > bad client modem behavior.

> We also sometimes get " %CONTROLLER-5-CALLDROP: Controller E1 0, Call DROPPED due to
> excessive errors" on the specific router. But we still don't get any errors on the E1.
> Could it be caused by poor circuit quality? If yes, how can we check it?

Yes, this would be caused by a sync HDLC/PPP call having excessive errors.
This is most likely caused by a poor circuit. 

The first thing you might check would be for BRI errors on the client
side.  If this shows as clean, and if your E1 is clean, then the errors
are evidently here:
                               |
                               v
[ AS5000 ]--E1 PRI--[switch]-{PSTN}-[switch]--bri--[ client]

In order to troubleshoot the PSTN, you will first want to get a 
map of the TDM network (i.e. the part between the AS5000's 
switch and the client's switch.)  Then make numerous test calls 
using different circuit paths through the PSTN, to try to find
a pattern for where the errors are being introduced. 

Aaron