ADSL Modem link light goes off, but reappears once land phone is reset.

[heavydemand]

I'm using BSNL Type III ADSL modem (Huawei MT841) for BroadBand connection.

My problem is ADSL modem link light goes off now and then. After so many experiments, my observation is once landline phone handset is reset, link light reappears and becomes steady. But how long it remains steady, can not be predicted. Generally the duration is 10-25 minutes.

Can anyone help?

 

[essbebe]

In ADSL Splitter
Check RJ11 from Phone Junction goes to LINE port.
Sometimes interchanged with Phone port.
( All Phones AFTER the ADSL Splitter ONLY )

Mention if problem suddenly started ?
From Summary page extract Mod selected
SNR Attn U/L D/L data and post here.

http://www.calcuttatelephones.com/dataoneinstall/drg07.html

http://www.calcuttatelephones.com/dataoneinstall/mdm06.html

 

[heavydemand]

All three RJ11 (a) from Junction to Line port (b) from phone set to Phone port (c) from modem to Modem port connections are OK.I have only one phone and that is surely after Splitter.Problem suddenly started. Just Link light went off. After so much error and trial, now I have the observation "Reset the phone. Link light reappears. Everything is ok. Now internet is accessible. Only problem is link light may go off again any time. Of course follow the same path i.e. reset the phone."When Link Light goes off, SNR data is following:SNR Up/Down : 0 db/0.0 dbAttenuation Up/Down : 0.0 db/0.0 dbWhen Link Light reappears (after resetting the phone), SNR data is following:SNR Up/Down : 27 db/31.5 dbAttenuation Up/Down : 13.0 db/27.5 db

 

[essbebe]

Start Network LAN propertiesnetwork settings page Select TCP/Ip propertiesDNSenter open dns 208.67.220.220 and 208.67.222.222Also enter same in modem select DNS menu. Uncheck automatically asiign DNS.enter above. data. Save reboot Wait for two minutes. check again. If still problem Option to set Mod mode ( auto /adsl2+ gmt/ t413 etc ) See In Summary page may be now adsl2 + change to GDMT. Save reboot wait for 2 minutes . Feedback.

 

[heavydemand]

Feedback

The problem is with ADSL modem Link light, in Isolation. Computer or internet access is not a problem.

If Telephone set, Splitter and ADSL modem combination, after power on, results into a steady green light on ADSL modem Link, then I know problem is solved. But that is not happening.

As computer itself or internet connection is not a problem, I have not tested putting DNS data, provided by you, in Computer.

But I tested with DNS data in Modem itself. Still problem is there.

The third option I have not tried out, because operation mode is already GDmt.

The point, again I would like to stress, is that once link light goes off, resetting phone clears all the problem. Once the phone is reset, link light reappears (This whole thing can be tested in Isolation - only with phone, splitter, modem).

I am wondering what's the relation between phone resetting and reappearance of green link light of modem.

If phone lines are bad, it can not be ok every time I reset the phone. Phone handset is not responsible, I think. I have tested with another good handset.

 

[essbebe]

Thank you for detailed report.
imagine what happens when you lift the telephone
handset from the cradle.
A short pulse ( the D.C about 40 to 60 V) is
removed and you get the Dial Tone.
At the other end when you dial a number
this DC energises the bell.
http://adslm.dohrenburg.net/images/splitter-diagram.jpg
So a short transition in the Line condition
affects your Data line also and you get reconnected.
test 1 :
Please check there are no other filters from the Telephone
junction( Old Black Box ) or a new one with anti surge filters.

Test 2 :
remove the telephone instrument completely.
Then when the Data line Internet is interrupted ,
switch off and switch on the modem again.
Do you get re-connected ?

Report :
1. See the modem log when connection is broken.
2. Does this happen when you lift the
handset to make a call
or receive a call ?

 

---

[sachins]

your loosing sync and you need to change your wires. if you think you can convince your lineman to change the wires then approach him else meet the divisional engineer and write him a request to change the wire from the DP box to your telephone.

 

[heavydemand]

Thank you for detailed report.
imagine what happens when you lift the telephone
handset from the cradle.
A short pulse ( the D.C about 40 to 60 V) is
removed and you get the Dial Tone.
At the other end when you dial a number
this DC energises the bell.
http://adslm.dohrenburg.net/images/splitter-diagram.jpg
So a short transition in the Line condition
affects your Data line also and you get reconnected.
test 1 :
Please check there are no other filters from the Telephone
junction( Old Black Box ) or a new one with anti surge filters.

Test 2 :
remove the telephone instrument completely.
Then when the Data line Internet is interrupted ,
switch off and switch on the modem again.
Do you get re-connected ?

Report :
1. See the modem log when connection is broken.
2. Does this happen when you lift the
handset to make a call
or receive a call ?


I was getting "Access is denied" when accessing the URL, provided by you. But that's not a problem to go ahead with other testings.

Test 1:
There is no other filter, other than the only Splitter, in front of Telephone Junction Box.

Test 2:
I completely removed Telephone instrument. This time there was no interruption in data line. Modem link light was always steady, for one hour. Generally link light goes off after 10-25 minutes.

So once again I connected the Telephone instrument. But unfortunately :huh: this time everything is working fine. Some problems can not be defined when they do not follow a regular pattern.


Report:
1. Though this time I was not getting any break in data line, the log is generally looks like below, when link light goes off really:

Jan 01 08:00:28 syslog: ADSL Training
Jan 01 08:02:31 syslog: ADSL Link Down

2. Connection never breaks during making or receiving a call.

 

[essbebe]

Source :http://adslm.dohrenburg.net/images/splitter-diagram.jpg
No problem for me.

as per diagram above, if nothing is connected at Phone end
the circuit is not complete !

Now In adsl modem both DATA and and telephone DC/will appear.
DC is blocked by Internal circuit of modem.
But as the circuit is open even if someone calls you there is no
break in BB connection. and there is no Voice signal to filter !

The filter shown above BLOCKS the DATA signal from
the Low frequency audio signals for telephone conversation.

Try RJ11 cable to Modem less than 2 feet length ( as
recommended in BSNL site ).

If interested: check SNR attn without any phone connection.

 

[rahul4640]

Will you just check if the Splitter is defective?

 

[essbebe]

@rahul4640.
Test 2:
I completely removed Telephone instrument. This time there was no interruption in data line. Modem link light was always steady, for one hour. Generally link light goes off after 10-25 minutes.

So once again I connected the Telephone instrument. But unfortunately this time everything is working fine. Some problems can not be defined when they do not follow a regular pattern.