dsl sync trouble

bren50c

hey guys.
i'm with gaelic telecom (imagine) and recently upgraded to 3MB broadband. had been previously on 1MB with no sync problems. Ive been googling sync problems and have since disconnected the extension on my phone master socket, which seems to have improved things. SNR has gone from about 6db to 7.5-8db, with less connection dropping.
The thing is i have an eircom phonewatch alarm on the line, which the technician apparently set up for broadband, but i'm wondering even though they put the filter on the phone socket, the alarm must create noise and lower the SNR?
ive heard of someone that 'split the line' so as the alarm and the broadband are somehow seperate, could this help me? It looks like there's a few blank spots on the graph - is this alarm interference?

below are graphs i got from dmt (http://dmt.mhilfe.de/ .. a great free program)

(top is before disconnecting extension, the bottom after)

dub45

Your line is not up to the increased speed simple as that - your snr is dire as is your line attenuation.

http://www.kitz.co.uk/adsl/linestats.htm


http://www.kitz.co.uk/adsl/lowSNR.htm

bren50c

yeah i know my line is terrible. i just wanted to try anything i can and leave downgrading as the last option.
the thing is that it often goes a day or two without a disconnect, and when connected the speed seems really good.
so if it wasnt possible with my line surely i'd get crappy speeds, and wouldnt stay connected for long? or am i wrong?

lucernarian

If it's possible to go without the extension, I'd reccomend to stick with the 3 Mbps speed. If the SNR drops, the rate adaptive DSL should trim back the speed and it may synced for most of the time.

This isn't conclusive, but the Netgear DG834G wireless router looks like it can handle low SNR much better. Something to consider.

bren50c

thanks for the replys. it seems to be doing much better today without the extension, so hopefully it will hold up. i think ill look into getting that router too.
anyone have any idea if the eircom phonewatch on the line makes a difference to the SNR? if so, is there anthing i can do to improve things?

Sponge Bob

thats a 1mbit line unless you get the 58db downstream to below 48db and also get the snr margin above 10 (its 6.5db) .

1. unplug everything from your line bar the modem ( but unplug the filters)
2. plug modem into main socket and run that test again
3. I love that dmthilfe prog of yours

bren50c

Sponge Bob wrote:

3. I love that dmthilfe prog of yours

i just got it for the sound effects the explosion noise when you get an error makes errors so much more entertaining...

disconnected eveything and ran the test again and snr is 6.7 and attenuation is the same at 58.5
i did see the snr get to 7.9 / 8 db earlier though. doesnt look like i'm going to get any better than that...

lucernarian

It's not a 1 mbit line if the SNR stays above 6 for most of the time at a 3 mbps package.

Attenuation is only half the story.

There are no filters to unplug, he has a phonewatch setup with a master socket filter.

bren, presuming that extension lead is between the modem and the DSL socket of the main socket, you definetely can do without it. The lead between the modem and the DSL socket should be the smallest that's possible for you.

If you can get the router and not mind the price of €70 to €80, it should stop the disconnects unless you get them every day. Good reports of it http://forums.vnunet.com/thread.jspa?messageID=803345

Sponge Bob

Man!!!!:( I am amazed that Imagine (aka Gaelic) would sell you 3mbits with stats like that. Could you try to see if eircom or digiweb would sell you 3mbits ...out of interest ..

phonewatch could cause this but I thought that phonewatch users had to get and pay for an engineer to install bb for them to avoid these issues.

IF you are , however, 3.5miles or so from the exchange the stats are genuine which begs the question of how any reputable operator could have sold that package to you .

bren50c

to_be_confirmed - i think youre right there. SNR's at 7.2 now. My speeds have always been pretty good, around 2.4MB down which i think is normal for a 3MB line. Hopefully i'll be able to get that netgear router.
I did have an extension line between the modem and phone socket which ive now removed. And I also disconnected the extension phone line that goes to the upstairs of the house - I found after I did that there was a noticeable difference in the SNR.

spongebob - yes a phonewatch engineer did install some kind of filter on the master socket when I said I had broadband. But I wonder do they care about noise on the line...i think there just concerned with getting a filter in and getting any kind of connection.