Fix Bsnl broadband frequent disconnection problem

By | November 7, 2012

Bsnl has plenty of high speed (4 MPBS) plans as mentioned here : .

These are on the NIB - II Network. Ip addresses begin with 117.

One known problem with the high speed internet is that it gets disconnected frequently. So like Yahoo Messenger or Pidgin or Skype could go offline every 5 minutes and then connect back.

How to Fix

Here are a couple of tweaks that might fix the problem.

1. Disable all modulations except G.Dmt Enabled. This will limit the download speed to around 4.8 Mbps (4984 Kbps) and the upload speed to 207 Kbps.

But can make the connection a lot more stable.

Change the settings in the admin panel ( and then restart modem.

2. Choose a LAN Ip with larger number in 4th octet like , , instead of ,

Not sure why it would effect the stability , but it may have some effect if multiple computers are using the same connection in a LAN.

3. Check the hardware

Make sure that the adsl line is stable - Link light stays stable. SNR Margin should be high and line attenuation should be low.

SNR Margin (Signal to Noise Ratio Margin) – You have to watch out for SNR Margin (usually in 20?s) and if it is too low you may get disconnected often.
Line Attenuation – It measures loss of signal over distance and its value in 20?s means excellent.

Meaning of various values are as follows :

SNR Margin
A higher signal to noise ratio will result in less errors.
6bB. or below = Bad – experience intermittent synchronisation problems.
7dB-10dB. = Fair
11dB-20dB. = Good
20dB-28dB. = Excellent
29dB. or above = Outstanding

Attenuation Rates

Attenuation is the loss of signal over distance. Unfortunately, dB loss is not just dependent on distance. It also depends on cable type and length of the cable, including location other connection points on the cable.
20bB. and below = Outstanding
20dB-30dB. = Excellent
30dB-40dB. = Very Good
40dB-50dB. = Good
50dB-60dB. = Poor and may experience connectivity issues
60dB. and above = Bad and will experience connectivity issues

Also check the following :

Phone line has not too much noise.
Wirings are not too old and torn
Splitter should be OK

About Silver Moon

A Tech Enthusiast, Blogger, Linux Fan and a Software Developer. Writes about Computer hardware, Linux and Open Source software and coding in Python, Php and Javascript. He can be reached at [email protected].


Fix Bsnl broadband frequent disconnection problem
  1. USPS

    My DLS Light of of modem DSL-2750U Down every 50 seconds and connection goes out. This setting not have any impact on it. BSNL customer care is also not dealing with this… ps. help

  2. Raphael

    Thank you very much whoever you are.My bb connection kept disconnecting every 5 minutes which was really frustrating.There are other useless infromation on other sites which were a conplete waste of time.Your solution deserves to get more attention from other helpless bsnl users.(PS-The first method worked for me)

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  4. jahar lal das

    mya name is J L das and i live in agartala ,tripura
    it is summer over here and for the last 4 days my dsl is blinking and there is no internet connection
    i have registered a complaint on the first day itself by calling 1500
    second day the line man came and checked but said everything is okay and by evening it will be alright , but it was not
    third day afternoon i again called 1500 and told them everything that had ocurred , the guy over phone said he is looking into the matter but nothing new
    fourth day it is the same case, i’m tired BSNL
    what should i do?

  5. Harshil Makwana

    Really hats off to you. The g.dmt trick did the work for me. I was tired from 1 month of complaining but this think did it in seconds now my speeds are 4 mbps constant. Once again thank you

  6. shailendra jaiswal

    My landline no 2660922 has been disconnected but my billl is clear and my bill is showing in minius what to do for reconnecting of broadband

  7. Tippu Sultan

    Hello There,
    Thanks for your wonderful tip.. Though, my SNR gone down from 29 to 25, my attenuation rate came down from 50 to 33.. I followed your G.dmt trick and disabled everything else.. I now hope that my conn now gets more stable though it wasn’t unstale till now..

    As a goodwill gesture, I shall award you with an Adsense click.


  8. Dilip

    Thank you very much. After doing what you have advised, my BSNL BB connection is rock steady. The article is of very high value.

  9. S Krishna

    You are a rockstar! You are awesome! My modem-cum-router was disconnecting every five odd minutes and reconnecting within two minutes, but, that make it impossible to communicate on Skype or even access Youtube for long videos. The change from Multi-mode DSL modulation to G.dmt seems to have done the trick. The line is perfectly stable and the speed reduction is not evident (on the contrary the Status on my modem-cum-router states an increased downstream rate (from 3997 kbps to 400 kbps).
    THANK YOU! SO MUCH! Chand sa roshan chehra…tahreef karoon kya uski, jisne tumhe banaya! Mashallah! Godspeed to you! Aapka chandni jyoti bani rahe barsoon ke liye!

    BSNL ought to thank you as well as this problem was getting year by year worse especially since I upgraded to their 4 Mbps plan and I was at my breaking point and wanted to seek disconnection and opt for my local cable operators Co-axial connection. I came across this site by serendipity.

    In case a personnel of BSNL reads this (highly unlikely) your broadband personnel ought to have known that the solution was not frequent change of router-cum-modem, but, rather a small change. Time to show that the leading ISP cares for loyal broadband customers who have been around since the days it was initiated as DataOne, seems your infrastructure or the modems that you provide were meant for 256 kbps lines and not these 4 Mbps lines. You are probably the third largest employer in India and yet you do not assist your patrons at all.

  10. koolhus

    Thanx a ton man…. My net connection kept breakin up during online games n all… but after ur first step it got solved…. thanx again…

  11. Harmeet Singh

    If your bsnl boradband disconnects frequently, then you can follow these steps to fix it:-

    1. Go to

    2. Click AdvanceSetup >> WAN >>

    3. click EDIT for 0/35 ( our net runs on this VPI/VCI)

    4. Click on Next

    5. Connection Type page will be displayed (Make sure PPP over Ethernet is selected)

    6. Click on Next

    7. Now we are on PPP UserName and Password page.

    8. Enter your PPP UserName and PPP Password :)

    Thats it ! your modep is now Up and Running.

    Coclusion :- moded has some problem as the values for username and password changes randomly to any r-bit value everytime when system is restarted or infact changes anytime.

    Problem is in the hardware of modem, it saves wrong credentials in the file and updates these wrong values on

    Hence, even if all lights are glowing, still it will not establish a connection with the server.

    So, one solution is , manually follow above steps and change the values.

    Permanent solution is , Go and buy TP-link moded (154 gsm compoared to 54 gsm of our present bsnl DNA-A-211-1 old modem)

    TP-LINK modem comes with 3 year warranty also. ! Sounds Great !

  12. bp

    disconnecting every 10 min.

    DownstreamUpstream SNR Margin:6.06.6dbLine Attenuation:1.06.2dbData Rate:242021159kbpsAttainable Rate:256201160kbpsOut Power:0.010.3dbm

    1. Silver Moon

      check the Datarate (downstream) towards the bottom of the page. it shows 2048 kbps which is 2mbps.

      if your broadband plan is 4mbps then your speed is capped/limited to 2mbps only. contact the sde of local bsnl telephone exchange to lift the cap and increase speed to 4mbps. once the cap is removed, the downstream data rate would show 4096 kbps or above.

  13. Sajid

    same issue i am using a dna a211 i modem it keeps disconnecting after 2 to 3 minutes
    dese are my stats what shud i do
    my snr margin is 13.2 in downstream and 7 in upstream
    attentuation is 27 and 16 respectively
    plz help coz it is getting really irritating for me
    i m frm kanpur

    1. Silver Moon

      the snr is lower than average. it should be around 18 for downstream or higher.
      attenuation is higher than average. should be around 22 or lesser.

      could be a cable issue between your house and the telephone exchange.

  14. Manoj

    Repeated siconnections on BSNL BB in Pune. It’s going on for 7 months now, and happens every 2-3 weeks. BSNL after calls and screams fixes after 2 weeks then off it goes again. Values as below :
    Mode: ADSL_2plus
    Traffic Type: ATM
    Status: Up
    Link Power State: L0

    Downstream Upstream
    SNR Margin (0.1 dB): 378 270
    Attenuation (0.1 dB): 70 39
    Output Power (0.1 dBm): 208 70
    Attainable Rate (Kbps): 21,476 588

    Path 0 Path 1
    Downstream Upstream Downstream Upstream
    Rate (Kbps): 2,048 509 0 0

    MSGc (# of bytes in overhead channel message): 59 81 0 0
    B (# of bytes in Mux Data Frame): 64 13 0 0
    M (# of Mux Data Frames in FEC Data Frame): 1 16 0 0
    T (Mux Data Frames over sync bytes): 1 1 0 0
    R (# of check bytes in FEC Data Frame): 16 16 0 0
    S (ratio of FEC over PMD Data Frame length): 1.0 13.612 0.0 0.0
    L (# of bits in PMD Data Frame): 648 147 0 0
    D (interleaver depth): 64 4 0 0
    Delay (msec): 16.0 13.6 0.0 0.0
    INP (DMT symbol): 6.32 1.74 0.0 0.0

    Super Frames: 268,785 246,116 0 0
    Super Frame Errors: 31 902 0 0
    RS Words: 998,792 76,031 0 0
    RS Correctable Errors: 0 0 0 0
    RS Uncorrectable Errors: 0 0 0 0

    Any ideas. The link lgiht as well as DSL light go off together every 3 minutes, and return after 3 minutes. Fed up with this provider.

    1. anon

      try enabling adsl 2 + t.143 .. if that doesn’t work then u can try a combination of each .tick adsl (g.dmt) as it is most stable though but with the rest u can play around

  15. Pavan

    Attenuation (0.1 dB): Downstream 80 and upstream 65
    SNR Margin (0.1 dB): Downstream 131 and upstream 230
    i have frequent disconnections every 2-5 mins they last for about 10 mins unless i restart my modem (D-Link DSL-2730U). My net plan is bsnl BB Home Combo UL 750. any ways make it stable please help

  16. D L S

    Have got a,
    Attenuation (0.1 dB): Downstream 430 and upstream 280
    SNR Margin (0.1 dB): Downstream 81 upstream 280

    The lineman in my area is really a stupid man, all he does is comes down at my home, sees if telephone is working fine and internet link is up at that particular time or not and then leaves.

    But very often as he leaves, internet disconnects. And this has been happening for over 2 months.

    I am based in Ahmedabad, Gujarat. Does anyone have any particular details about technical support of BSNL Office or something? I have tried 1500 and 1504. No proper response. They register the complaint which I can anyways do myself using “Automated Complaint Booking Service” and then the same stupid lineman comes and goes.

    Thanks, I look forward to your response.

      1. D L S

        Nothing worked, finally found out the email address for Ahmedabad SDO and emailed him, his assistant called me up and arranged an immediate visit from an engineer, he saw the Attenuation was over 430 something, he said its just because my home is around 6 kms from the exchange, he asked the local lineman to once again change the cable.

        Now lets see if it really gets sorted.

        Internet speed has greatly reduced in past 3 hours, whereas I have actually submitted application about 15 days ago to upgrade to a higher package from 1 Nov 2012.

          1. Silver Moon Post author

            my connection became much more stable and better after changing the adsl modulation setting as shown in the post.

    1. parth gupta

      just make a complaint on 198
      make complaint of landline
      they’ll call u
      ask them to change the wire with many joints to single wire or less joints
      ask them to change the “whole wire” to new wire
      or tell them that u’ll get ur connection disconnected because of poor bsnl service
      make sure if they don’t do, then give a written complaint to the head of dept.
      if u can; then just ask them to install a cable, like the tv cable
      new one
      have fun

  17. Mirza

    Thank you for this post, It really solved my disconnection problem. I was really fed up with this frequent disconnects and about to leave Bsnl and subscribe any other ISP. Now everything works fine.. Thanks again.

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