> We have that same problem periodically, D channel setup but no data.
> It has to do with the interconnect and route the call makes coming (in our
> case) from USWest into GTE.
> Have the user back the ISDN modem down to 56K and try to connect.
> It supposedly takes the encoding out. There are two possible things
> that can be wrong according to the GTE guy. A switch is encoded wrong or a
> span somewhere is only 56K. There is usually a local (to you) test number
> that loops
> back the data to the caller. Try and get that number and have the user test
> the
> modem calling it. The test number they give an ISDN customer is the first
> switch
> (user) not the last switch (PM3). You want the test number for your co.
>
> I feel your pain.
>
....... stuff deleted ..........
One way that this manifests itself is during peak call periods. Here
the switches will change their routing and who knows what path your data
will follow through their network. What makes it even more difficult is
that this will appear as a sporadic failure - very difficult to
reproduce.
The fact of the matter is that the Telcos are starting to show their
age! Some of this routing stuff may have been setup years ago - and the
guy who set it up is no longer with the company!
I had a client setup a couple of years ago where the Telco (SWB) offered
an ISDN special and my client got 2 ISDN lines (on switch A). About 4
months later he got another ISDN line (switch B), 3 months later another
ISDN line (switch C and switch D - yes the Telco split it on 2
exchanges). In each case they ran out of capacity on the original
switch (A) and moved onto the next switch with available capacity. I
had them setup a hunt group - and yes you've guessed it: this was
implemented as call forward on busy. So someone calling in for the 2nd
B-Channel on the last available ISDN line would tie up resources on
switch A, switch B, switch C and switch D!
And the Telcos are complaining about call volume and people grabbing
circuit switched resources......
Al Hopper Logical Approach Inc, Plano, TX. al@logical-approach.com
(972)-379-2133 or (972)-849-5765. Fax 972-379-2134
If you aren't confused, then you simply don't know what's going on!
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