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Are there any documents listing ADSL circuit & distance limitations??

I've used ADSL thru a BS reseller for roughly 4 yrs now. Install is by the book, minimal DSL line run from Demarc(8ft), proper filters, min phone setup, etc.. Wire loop length ~12000ft to BS CO. (I use to be a Beta site for telocity/DirectvDSL DSL modems.).

Problem, quality of BS supplied DSL service in the last 1.5 years has steadily dropped. For several years I've gotten 1.5M/256K with ~62/38% utilization. Lately, DSL service rarely hits 1.5M/256K. (100% down). Noise profile now insures I'll never see more than 1200K down. Location South Florida, zip code 33064..

Modem retrains lower several times a day.. (Characteristic 5 to 10 second loss of ping respone/IP connectivity to/thru 1st hop router). Seams to follow neighborhood DSL usage patterns. Highest speed occurs in the early morning after power cycling modem. (Most DSL modem's don't normally retrain upwards as line conditions improve.) Starting around noon, DSL line noise exceeds threshold and renegotiates lower(1100/256K).. and lower(750/256k). Evening is the worst. (400/256). Downstream S/N is marginal around 8.5 dB. Swapping out modem with newer modem had little effect.. (The newer modem is consistently slower).

Discussions with other Neighborhood BS DSL users have all indicated problems with BS DSL speeds being significantly lower than advertised. I have personally observed BS making dozens of service calls in this area attempting to patch.. and patch.. A regular DSL Nightmare. (BS service techs admit to that)..

----------- Question 1, Does any one know of a source for Authoritative Documentation for ADSL Distance verses Line/Cable density limitations? Question 2, Does any one been successful in getting BS to deploy an RT in order to improve DSL service? If the answer is yes.. Whom did you talk too?

Reply to
Tim Keating
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One location in Texas reported loss of DSL during the afternoon hours - the copper pairs in the area were strung overhead and stretched during the hot hours so that they were too long for the service to work. Are your telephone wires overhead or underground?

Reply to
Kay Archer

99% underground, 1% overhead (service drop).
Reply to
Tim Keating

Underground to the pole in the back yard, then up the pole, then drop? At

12,000 feet from the CO, 1% overhead is 120 feet! Ah, yours must be the first drop at the beginning of an aerial run.

How old is the copper in the neighborhood? On the premises? For the whole run?

Reply to
NormanM

Correct .. Yes.

Each service drop pole has a 25 pair underground cable servicing it.. They're spliced into a larger cable until it hits the main underground cable on cross street. (200 maybe 300 pair) a couple of blocks down the road. That cable along with several others run's

3000ft down to the first junction box. from that point on.. I don't know the cable config.. except that it's all copper and underground to the CO..

Just guesses.

Copper in ground.. 20.. 30 years.. (2nd cable for pole) Overhead.. 15-25 years..

Premises... Cat-5 (all inside wiring).. 4 years.. (Max). All previous phone wiring has been retired.

DSL filter separating phones from DSL modem circuit is located ~1ft from exterior Demarc. (Interior garage wall.. opposite side from Demarc..)

Disconnection of all POTS circuits makes little difference.

Reply to
Tim Keating

Noise profile is set @CO.. by BS.. It Increases the amount of forward error correction and interleaves downstream packets (spreads out data time wise) to in an effort to increase link reliability. Costs you extra latency(40ms), plus 15% to 20% of your bandwidth.

BS did send a tech out with a meter. Of course this was during the day, when the line is relativity unimpaired.. (Majority of other DSL users in neighborhood not home or online).

The real threshold is what your DSL modems sees.. Most of them keep track of the accumulated errors for each minute. If they exceed a certain threshold, the modem will retrain.. (Retraining sequence normally takes 8 to 10 seconds, you will loose IP connectivity during this time)

Not really a good test. My (amp'd) speaker phone picks up a slight hum and background white noise 24x7. Occasional scratches are usually the result of lightning strikes within a few hundred miles.

Reply to
Tim Keating

What is the "noise profile"? Are you putting a meter on the line to measure noise? If so, what are you using?

I may have a similiar problem in NJ and am curious how you measure the circuit for noise.

My procedure is to dial one digit and listen to the circuit and make a subjective judgment as to whether it is quiet, noisy, occasional scratches, hum, etc.

Reply to
Arnie Goetchius

Thanks for all the explanations. I'll keep an eye out for retrains but so far I don't believe there have been any.

Reply to
Arnie Goetchius

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