Issue with P-871M (point-to-point connection)

AntonAnton Member Posts: 4  Freshman Member
edited March 22, 2018 9:05PM in Discussions
Hello Team,
I have an issue with establishing the connection between two 871m VDSL modems.
My conditions: cable length is about 600 meters, the resistance on the line is 307 Om, two 871M modems.
DSL indicators were blinking but connection was not able to establish. After I've reset settings to default on both devices the connection established but I don't satisfied with results, see below for details. My question is - is it possible to get better (faster and stable) the connection in my conditions? What should I start to tune to achieve it: srv, interleave delay or uprate/downrate values? Should it be configured only on CO side?

Thanks in advance and forward my questions to the right way (branch) if it's wrong.

(the first value for Upstream, the second for Downstream)
Actual line rate: 832, 17600 (Kbps)
Actual net data rate: 640, 15744 (Kbps)
Actual snr margin: 0, 39 (0.25dB)
Actual interleave delay: 0, 0 (ms)
Transmit power: 1000, 1340 (0.01dBm)
Receive power: -1625, -2260 (0.01dBm)
Actual INP: 0, 0 (us)
Total attenuation: 144, 105 (0.25dBm)
Attainable net line rate: 888, 17640 (Kbps)

VDSL Counters
CRC: 0, 0
ES: 11, 0
SES: 2, 0
LOFS: 497, 60
LOSS: 861, 5
RSCorr: 0, 0

All Replies

  • JameslaJamesla Member Posts: 10  Freshman Member
    Hi Antom

    According to the line status, the SNR margin is lower than 10dB.
    It seems there is much interference around the line or the line quality is bad.
    Is it possible to check the line and the environemnt?

  • AntonAnton Member Posts: 4  Freshman Member
    edited April 5, 2018 9:57PM
    Hello Jamesla,
    Thank you for your answer. Unfortunatly, we are not able to check, change anything or somehow improve our line. But after some investigation I have new conditions. I've done many attemps to connect my devices in different ways (CO on side1 and CPE on side2; CO on side2 and CPE on side1, replaced devices from on side to another, replaced power adapters for these devices, with splitters and without splitters, played with properties like snr, profiles etc) and I found only one way when it works. Only one! My current working scheme is CO on side1 and CPE on side2, profile (PSD:997-M1x-M) and snr is 0.
    That would be OK but I need that CO will be on side2 and CPE on side1 (technical requirements). And it is horror - when I swap devices by their places with absolutely the same settings they do not work - connection is not able to establish at all. How it's possible. In case my line is so bad I would not get connection between my devices at all. I'm I right or my understanding is wrong?
    I have only one idea - one of my modems might be damaged and works incorrectly.

    Any ideas?
  • AntonAnton Member Posts: 4  Freshman Member
    Forget to mention the statisctics which I've got:
    (the first value for Upstream, the second for Downstream)
    Actual line rate: 15968, 39456 (Kbps)
    Actual net data rate: 14272, 35392 (Kbps)
    Actual snr margin: 16777215, 6 (0.25dB)
    Actual interleave delay: 0, 0 (ms)
    Transmit power: 1160, 1340 (0.01dBm)
    Receive power: -1365, -2260 (0.01dBm)
    Actual INP: 0, 0 (us)
    Total attenuation: 186, 101 (0.25dBm)
    Attainable net line rate: 15976, 39516 (Kbps)

    VDSL Counters
    CRC: 1176, 1138
    ES: 118, 111
    SES: 2, 5
    LOFS: 0, 0
    LOSS: 122, 2
    RSCorr: 2508792, 854205
  • AntonAnton Member Posts: 4  Freshman Member
    Actually, now I have more questions than before. The main - why the connection is not able to established after I swapped modems by their places. I have not changed settings and the line remains the same. How it works?
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