  justbits More fiber than ATT can handle Premium join:2003-01-08 Chicago, IL
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edit: June 12th, @05:13PM
| reply to justbits Re: Any 5100b technician page DMT/SNR data experts?
Let me add some history. The 3.0/512 Pro profile as shown above worked for all of April 2005. Starting May 1, 2005, the line would lose sync twice a weekday. During the problem period, the line mysteriously grows 2000-4000 feet in length according to the DSLAM.
Recently, SBC has tried to solve the problem shown above by switching me to a replacement pair of wires, that exhibits the same problem I described in the earlier part of this thread.
The latest resolution was to switch me from the 1.5Mb/384 profile to 768/384. So far this weekend, the line hasn't lost sync at the lower speed, but it does exhibit what I believe to be amazingly similar graphs when compared to the same kind of graphs I was seeing at 3.0/512 profile speeds. Notice how the nice stair-step DMT graph goes into a jagged lower-quality signal during the problem?
Here's the line as it looks just before the problem.

Here's the line as it looks during the problem.

Here's the line quality after I power cycled the modem a short while later. (It stays looking basically like this from 1pm til 6am the next morning.)

Does anyone have any expert knowledge on the SNR/DMT values/graphs I'm getting from my 5100b?
By the way, I have QuickTime movies of the problem drawn graphically for the last 16 days.
Thanks, --justbits |