Thread: Of modem connections, line SNR and splitters

Hi guys.

Unfortunately, those who came to this thread looking for help for these line problems may not find any solutions since I am cribbing about my own problems here! However, I'm going to try and offer my solution "theories" before trying them myself!

This might turn out to be a long post, so hang on...

1. The setup:
BSNL Home 1000 plan (night unlimited)
Huawei SmartAX MT882 USB+LAN modem
No. of BSNL landlines in the house: 2 (different numbers, one main and one secondary)
Number of extensions in the house: 5 for the main line; 1 for secondary line
Number of splitters used: 1 only (before the modem and one extension, splitters NOT used on other extensions -hint hint- )

2. The disclaimer:
Here, oddly enough, I am NOT complaining about my broadband speeds after getting connected, both during regular use hours and 2 am - 8 am. In fact, I can consistently hit 2000-2500 kbps DL and 400-500 kbps UL in Speedtest.net and I'm lately getting torrent speeds of 150-200 kbps EACH for good torrents (ones that are well seeded, etc.).
My complaints have to do with GETTING CONNECTED and keeping my connection STABLE!

3. The problems:
a. Ever since I got the BSNL dataone connection, there have been times when the modem's connection is totally fine, but all of a sudden I won't be able to browse to any web pages after browsing for say, half an hour (it will just say, 'connecting to http:....' or 'waiting for http....'). This would then require me to turn off and on the modem, resetting the connection. Browsing would then be fine after that.

b. (a weird one) Somewhat recently, a lineman had come in to reconnect the house's secondary line to another room. It was after this that I started facing a weird problem during connecting the modem to the net, which I believe is caused by the line SNR (due to the number of extensions in the house which are not "splitter'ed"):
The Huawei modem's link light (which turns amber after successfully establishing a net connection) stays green after turning on. It never turns amber to confirm an established connection (it's not just the light either - the net really wont work at this point).
I was distraught for a day before I discovered this solution to get the modem to connect (try not to laugh or be too impressed please):
I have to pick up one of my extension phones (not the main one connected after the splitter, but one of the unsplit phones), listen for the dial tone
a couple of seconds, and hang up. Since this causes a sharp drop in the line SNR, the modem resets (link only, not a full reset) to reestablish the link. However, this does not work the first time. I have to pick up and put down the extension phone a SECOND time. After this is done, THE MODEM'S LINK LIGHT TURNS AMBER, SIGNIFYING AN ESTABLISHED CONNECTION. Strange part is, the picking up and putting down the extension phone has to be done exactly twice every time....after this, I'm able to browse/download/etc. properly.
(see, I told u it was weird!!)
Until the lineman/technician comes back to fix this, I'm living with this annoyance. Which isn't TOO bad, but the bad thing is I can no longer rely on an automated modem reset at 2 am before downloading torrents! I have to use the phone ritual at that time also to reset the connection!

Solutions/theories to follow in next post...gotta run!

-Parvez

On to the next part of this monster (for me anyway) post:

Solutions refer to the problems given above (3a and 3b).

3a. Modem losing connection even if indicating an established link
I used to think this may have also been caused by low line SNR, but it may actually be caused by the modulation type selection (I used to use ADSL2+ because of the sometimes higher speeds). Since I switched to G.DMT, this problem crops up less often (while maintaining good speeds) but still does occur from time to time. Any other suggestions for this one?

3b. Modem not connecting unless extension phones are picked up and put down (twice)
The obvious cause of this problem is the line SNR, although I never faced this before even with all my extension phones connected (I've actually since disconnected a couple of them to see if that'll help - no such luck though). I'm thinking it has to do with the way the lineman has wired the secondary line connection which is somehow interfering with the main line connectivity.
Therefore, the first step would be to get the lineman back and tell him to look at this issue and maybe go back to the old wiring scheme he used.

Do you guys think there could be another method to wire a secondary line so that it doesn't interfere with the primary? Or any other suggestions?

The next step I guess is to use splitters at each EXTENSION phone around the house also. But how do I connect it? Do I just get a splitter and first connect the phone line to it and connect the phone to the 'phone output'? (with 'modem output' not connected to anything?)

Any other comments you guys have? If you have managed to read both posts this far, I REALLY APPRECIATE UR PATIENCE! WOULD APPRECIATE EVEN MORE IF YOU CAN OFFER SUGGESTIONS....:surrender: THANKS!

To improve SNR Margin and having less disconnections, please try the following:

a) The incoming telephone line must go to splitter directly. No parallel lines before that.
b) Voice and data lines completely separated.
c) Try to avoid phone lines running too close to electrical and TV cables. Frequencies of these lines introduce indcution based noise and eddy currents in each other.
d) Ask new external wiring done from exchage box to your home.

I used to suffer from problems similar to yours. Please see my sticky post in this forum (My interactions with BSNL).

the thing with bsnl is,they disturb other people connection accidentally while repairing the other people connection,i know its unintentional ,but cmon they need to check whether they didn't do any mistake

and the worst thing is ,these technician dont have any idea abt broadband they know only abt telephone lines


a technician shud be aware of broadband troubleshooting also ,

your right.. bsnl lineman dont know that telephones must be connected after splitter.. so in most homes its connected the wrong way.. and hence disconnections and disturbances..

@pjaveed
Good essay and explains clearly the problem/s and solutions.
for even a layman to understand.
http://i34.tinypic.com/s4c0me.jpg
See the path of telephone signals and Data signals.
1.Connect extra ADSL splitter to each extension line or phone .
2.Use Short cables.
3 ensure there is no Junction Box Old type
with a RJ11 port in your telephone connection .
This will attenuate the data signals)
Para two :Your modem MT882 adaptor is for 12 V A.C
Any power surge could affect the modem settings.
Also when Phone is in cradle and lifted
the line DC ( 40V to 60 V D.C) transient pulse
will affect the modem.
Even if an UPS is used, if the change over
time is more than 25 ms
your connection likely to be disconnected.

hey guys, thanks for all your excellent replies (sorry you have to keep repeating yourselves on a lot of threads regarding connections )

well, the lineman's come today and I've explained the problem to him (unfortunately over the phone since I was at the office) and told him to make sure there's a splitter at the main line itself, and told him to look into the problem of low signal level in the line (I didn't bother trying to explain, in detail, the pick up/hang up phone phenomenon )

let's see what he does, although I would be pleasantly surprised if any good comes of his visit...I'm hoping he's at least put the splitter on the main line. I can look into the SNR problem after evaluating the network today at home.

cheers, mates! and thanks for your help - I'll keep all ur suggestions in mind for the near future...