Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!aurs01!luce
From: luce@aurs01.UUCP (J. Luce)
Newsgroups: comp.dcom.modems
Subject: Re: Line Noise Redux
Keywords: Line Noise
Message-ID: <59468@aurs01.UUCP>
Date: 22 Jan 91 17:28:13 GMT
References: <1991Jan13.183631.27081@europa.asd.contel.com> <59437@aurs01.UUCP> <1991Jan20.204546.5398@europa.asd.contel.com>
Sender: news@aurs01.UUCP
Reply-To: luce@aurw46.UUCP (J. Luce)
Organization: Alcatel Network Systems, Raleigh NC
Lines: 75

In article <1991Jan20.204546.5398@europa.asd.contel.com> enger@seka.scc.com writes:
-John:
-
-You responded that the DIRECTION of data corruption DID NOT CHANGE
-when you reversed the roles of the tx/rx tones.

That is correct...

-
-If the problem were frequency related, then it would seem that
-the 'direction' subject to the errors should have reversed.  
-Since it didn't, maybe we can assume that the problem is purely
-directional in nature.

My contention all along and 1 that was suggested by Floyd at Alaska
Com(?).

-
-You mentioned that you were feeding into a SLIC.  

I was moved completely off the SLIC to a different frame. *NOW* the
SoBell people tell me I am on a No. Telecom DMS-100 digital rather the
aforementioned AT&T analog switch.


-If that unit is close by, perhaps its possible that you're 
-overdriving its input.  You might want to try padding down (REDUCING)
-the output level of your modem to see its effect.

I am quite a ways away and go through a 'box' containing T1 cards onto a
fibre down to the C.O. I am about 2 miles from the T1.


-
-The only remaining avenue open to you may be to perform a full technical
-analysis of your line.  In theory, you should be able to get telco
-to dispatch a tech with a transmission test set to your premesis.
-They should be able to test for distortion at various signal levels/frequencies,
-noise on the line, and other degredations.  

I have requested that and have gotten the old "We only check the center
of the freq. range, we can't do a sweep'.


-
-If you can't get telco to cooperate, you could rent the test equipment
-yourself and take a stab at the diagnosis.
-
-Good luck,
-Robert M. Enger
-CONTEL Federal Systems
-enger@seka.scc.com  (Internet)

Also, I should note here that I am atteched inside to an RJ45S
connector now, the kind they use on 'data conditioned' line. I was told
(confirming Floyd's contention) that this is the only difference between
a 'voice' line and a 'data' line. Actually, there is another, a data
line is billed at business rates :)

I have been referred internally to some one 'who knows these things...'
and he is going to get a data-line knowledgeable sort on the case. Of
course that was a week ago and ... (you know, when cows can fly) :)

As for the test eqpt... being a s/w engineer, I am ignorant of a lot of
that stuff (and plan on staying that way <heheheh>).

Thanks, for the info. If you have more ideas, let me know.


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