India Broadband Forum

nilaynashikkar

For the past 1 week, my dataone broadband connection is giving me trouble. I have a Smartex MT882 modem and since all the lights are green and steady, i think it is in working order. inspite of that i am getting disconnected very frequently. Can anyone please help? I have tried to contact bsnl people on this number 1957 but no one is picking the phone

whitestar_999

open your modem configuration & look for some status page.in there check that SNR values are above 10.SNR(upstream/remote)should be at least 15 & SNR(downstream/local)should be at least 26-28.similary Line Attn(upstream)should be at most 15-16 & Line Attn(downstream)should be at most 28-29.larger SNR values the better.smaller Line Attn values the better.

nilaynashikkar

This is what i got

Upstream DownStream


ADSL Link Speed 640 Kbps 2631 Kbps

Previous Tx-Rate 640 Kbps 3082 Kbps

SNR 19.2 dB 12.0 dB

CRC 0 0

Attenuation 36.5 dB 58.0 dB
FEC 0 0
HEC(ATM Layer) 0 0

The SNR and Attenuation is different from what you had suggested.
So what should i do?

nilaynashikkar

please somebody help me

whitestar_999

your upstream & downstream Attn are very high & SNR values are too low.get your line checked by bsnl.also make sure that the line coming into the house goes directly into the splitter.no phone/phones must be connected before splitter.

pjaveed

Hi all,

after looking through this forum I've also discovered this workaround for increasing your overall SNR to ATTN ratio:

In the modem's ADSL Settings page (for MT882), change modulation to G.dmt if not already done so.

this, for some reason, may keep SNR at around the same level but significantly decreases line attenuation (due to modulation changes im guessing).

interestingly, i did a speed test of both the ADSL2+ modulation and G.dmt and G.dmt (with bitswap enabled) gives higher DL speeds!

whitestar_999

G.dmt is the standard used by BSNL & by default enabled on all modems provided by BSNL.unless you made some changes in BSNL provided modems default settings your mode should be G.dmt.

strider

Help, these are my values
Up Down
SNR Margin (dB): 14.4 9.0
Attenuation (dB): 24.0 10.5

Rameshjeee

My broadband connection disconnects every 10-15 min.

Modem type: SmartAX MT-841 (Type III)
SNR Value: 24 db / 7.5 db
Attn Value: 26.5 db / 48.5 db

Kindly help me in locating the exact reason for this disconnection.

whitestar_999

SNR value of 7.5db is the problem.it must be above 10.Attn value of 48.5 is also high.read previous posts & if still problem exists you need to get your line checked by BSNL.

strider

What about mine as posted 2 posts before??

whitestar_999

@realton,same goes for you.SNR values below 10 will mean frequents disconnections.2 things anyone can do is--->1.check that line coming into the house goes directly into the splitter & no phone/phones must be connected before splitter & no cuts/joints in line.
2.mode/connecting standard must be G.dmt not ADSL2/2+.
if still SNR values are low then you need to get your line checked by BSNL.

strider

Thanks, the first remedy is fine, no problem with the splitter and one more thing, my modem says its G.dmt too!! Its funny that although my browsing speed too suffers, but my torrents go super speed at 200+ KB/s(H 500). I use BitComet, why do you think, there is such a wierd problem.??


P.S The name is Relton and not realton. Chow!!!

whitestar_999

when browsing problem is there does bitcomet is running in background?

strider

Even when BitComet is running or off, the browsing speed sucks but like I said torrent go zoooooooooom!! I am very happy with torrent speed but because of frequent disconnections, I got annoyed.

whitestar_999

then i think you need to get your line checked by BSNL for noise,resistance/earthing problem etc.

strider

Yes, I will surely do that, But these BSNL chaps/BABUS are crap people. Very Non-reactive people in BSNL

pjaveed

guys now I'm sort of confused...I know I was a big supporter of G.dmt modulation for higher SNR levels, but now....

Until only last week, I've been using ADSL2+ modulation on my router. True I had low SNR values, but didn't face frequent disconnections or anything. Not only that, but my downlink speeds in ADSL2+ mode are much higher than in G.dmt!!

A couple of days ago, I was getting higher DL speeds (using speedtest.net) with G.dmt, but now that I've switched back to ADSL2+, I'm seeing a significant increase, even more so than G.dmt ever was! Wtf is going on??

Finally, I know some of you had said that G.dmt is the default modulation on the BSNL routers, but mine came set with ADSL2+!

just4kix

I think that you should go for whatever gives you best performance. Stick with ADSL2+. If problem persists, switch to G.Dmt.

I have found that ADSL2+ and G.Dmt both work equally well.

whitestar_999

well speeds should not be that different while using either modes.you may get better speed test results but that doesn't mean that you will get 1.8mbps in G.dmt & 2mbps in ADSL2.maybe a few KB's at most but difference won't be that much.as long as SNR values remains above 10 disconnection won't be a problem in either mode.