At this site the problem was a faulty callbuffer on the PABX
system. It caused delays in send data to the system.
The problem at the end of the day was caused by a faulty TMS.
They are using the MAN 3000, which has a call buffer unit,
that was faulty.
The faulty TMS had the following effect:
Some calls was not coming through to Amethyst, however they came
through to the system as soon as the call buffer unit was replaced,
as far as I could determine.