wrote:
I don't have quite the same problem, but we broadcast a radio show out of n
ashville, tn and we connect daily to a remote studio in washington DC via I
SDN connection. Both sides are using telos zephyrs. Periodically we will ha
ve digital interference on the receiving end in DC (sometimes it bleeds thr
ough to our side.) The interference sounds like a "chirp" or harsh high pit
ched scraping noise that lasts about a split second.

And it happens on a regular interval? If you time them, you get exactly
the same distance between them? If so, someone has a clock that isn't
synched up right (and it's apt to be one of the telcos).

Our carrier in Nashville is ATT, and on the DC side it's verizon. We also c
onnect to many other studios on a daily basis in Texas, Georgia, and NY, an
d NEVER have had this issue. All of our gear and our lines have been tested
and cleared on this end (Nashville). We have also had a Verizon ISDN tech
go to our DC location and run a BRI test from those SPIDS to the local C.O.
and his tests were clean.

The clock can be free-running and all his tests will be clean unless he keeps
running them long enough to see an error.

We have seem to do everything possible, but the problem persists.
Any ideas? (sorry for the length and wordiness)

A letter to the PUC never hurt anyone. Your goal is basically to get the
telcos to find the one ISDN expert they have on staff out to look at it.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."