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Montpelier, VT

1 edit

[connectivity] HELP! Speedstream 7500 Transceiver Statistics

Hello all! Can anyone explain the Margin (db) numbers and what I should be pushing Fairpoint to do?

Transceiver Information Down Stream Path Up Stream Path
DSL Speed (Kbits/Sec) 16468 1025
Margin (dB) 3.8-7.7 16.5
Line Attenuation (dB) 29.5-30.0 13.4
Transmit Power (dBm) 15.6-17.0 12.6

I have an intermittent connection at best. I have a packet loss of 6-20%. My Down Stream Path Margin (db) used to be 8.0 - 9.8 from when service was started in 10.1.12. The Modem and the NID were replaced last week. Not that the Modem showed any signs of fault. What other numbers should I be looking at? Fair Point seems to think that because the Download speed is over 15mb that there really can't be an issue. That "DSL Speed" does not mean much when one can't get on-line.Thank you for any help that can be given on this.

More info: The 7500 is connected directly to the NID. We have VOIP (Vonage, new router).

Milford, NH
·FirstLight Fiber
·Hollis Hosting
·G4 Communications
Welcome to BBR.

The higher the value the better. 8-10 dB is reasonable minimum margin. Once it falls below that modem will have a difficult time maintaining sync. ADSL2 does a somewhat better job at low margin then ADSL.

At 30 dB attenuation you are pretty close to the central office about 7500 feet.

First step is to determine if anything within your residence is degrading performance. If so that is under your control to correct.
Temporally connect the modem at the phone company NID test jack. The NID is the demarcation point between phone company and customer responsibility. If sync rate or margin are significantly better at the NID something within your residence is degrading performance.

ADSL is adaptive so restart the modem at each location.

If ADSL shares the same line as phone think about installing a whole house POTS/DSL splitter. Splitters do a better job isolating DSL from voice.

Assuming DSL shares a phone line, how is voice quality? Any noise on the line especially when phone is first picked up. What about crosstalk, other voices. If voice service is not up to snuff call voice repair to have the line checked.

Once you have done all that and if margin is still poor the only solution is to show down the connection.

As far as packet loss that may have nothing to do with the DSL circuit itself. Try to determine where in the path it is occurring. Do a traceroute (tracert in Windows) to stable sites like this one. Latency should slowly increase with distance and hop count. Sudden unexplained jumps typically indicate congestion at that or the previous hop. Keep in mind ICMP Eecho Request (Ping) is handled at a very low priority and some routers and servers do not respond at all.

What is more important is constancy, if you see widely varying response times that is an indication of congestion. That has nothing to do with your physical DSL circuit but rather back haul out of the DSLAM or elsewhere within the ISP network.



reply to Ghost11
Loop length might be a problem here.....you are not pulling full bit rate on the download or upload side so it makes me wonder how far you are from the CO......if you are over 5000 feet for the 15/1 plan you are too far.....there could be bridge tap somewhere in the loop that is causing a problem too.....with the 15/1 plan you should really have a ADSL splitter at the network interface to get the best connection to your modem.....I install these everyday and those are some of the things I find.