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Re: Lower sync than expected

youngsyp
Grafter
Posts: 104
Registered: ‎01-11-2010

Re: Lower sync than expected

Watching this thread with interest as I had a similar situation when I was first connected.
In my case, as Plusnet had failed to send the router out in time for my switchover, I was ADSLess but still had my Be supplied TG585v7 connected. That sync'd at 3500Kb/s ish. When I got the TG585v8 from Plusnet a week or so later, the best I've ever sync'd at is 3104 Kb/s (currently). My line has supported 4084 Kb/s for 3 years prior to that...
Paul
youngsyp
Grafter
Posts: 104
Registered: ‎01-11-2010

Re: Lower sync than expected

Quote from: Mav
Is it worth trying with interleaving off?
That will improve your sync and throughput however, were you on fastpath previously, when you hit you faster sync?
If not, it's not a fair comparison and will brush any potential issue under the carpet...
Paul
ETA: Without meaning to point out the obvious.  Embarrassed
Mav
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Re: Lower sync than expected

Mmmmmmm, you've just reminded me (not sure how, though ;)) that I still have a NetGear router somewhere to try. I'll look for that - it may be at my old address which I won't be going to for a few days.
AFAIK I've never been on fastpath.

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Mav
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Re: Lower sync than expected

@ Jojo
I may be stabbing myself in the foot here but I have been undercharged this month. I'm on a Market 1 exchange but being charged per Market 3. I'd be the first to complain if I was overcharged, so...
Edit: Thinking about it, perhaps I should have started a new thread for the undercharge. Mods....?

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jojopillo
Plusnet Alumni (retired)
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Posts: 9,786
Registered: ‎16-06-2010

Re: Lower sync than expected

Hi Mav,
[quote=Mr. Honesty]I may be stabbing myself in the foot here but I have been undercharged this month. I'm on a Market 1 exchange but being charged per Market 3
Thanks for the honesty there but if you move to a different market area from market 3 you still keep the price until the end of your contract.
Jojo Smiley
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Re: Lower sync than expected

I never knew that. Thanks Jojo

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Mav
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Re: Lower sync than expected

I seem to have had many disconnects over the past few days and around midnight last night re-synced at just over 4100, so I now have a profile of 3500 Sad
I finally got hold of my Netgear DG834G V4 (V4.01.40 firmware). It is plugged directly into the test socket and immediately synced at 5376. S/N margin is currently 0dB and Att is 46dB. The S/N seems to fluctuate between
4 & 0 (Routerstat graphs below).
Not sure how stable this line is and assume the vertical bars in the Sync Speed graph means that disconnections occured at those times.
A couple of other questions still unanswered:
Would I get faster throughput if I synced at 5588 rather than 5120 even though the profile would remain the same at 4500?
Is it worth trying without interleaving to see if I can achieve the 5568 I originally got?
@Jojo
This page still shows my old number. I understand you say it doesn't affect my connection but I don't understand why it has never been updated.
Also, why does it say :
Quote
Estimated line speed:
   4 - Checked on 2010-11-07 22:48:06

This was the day before I moved and it the internet was still on at my old address at that time.
Thanks

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spraxyt
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Re: Lower sync than expected

I think the vertical bars in the sync speed graph are most likely to be missed data collection points (router busy with other tasks and slow to respond to routerstats) rather than loss of sync. Generally if sync is lost the sync speed changes on reconnection, and the dips are V shaped since it takes a finite time to reconnect.
The noise margin is rather lively and in my opinion uncomfortably low for maxADSL. The router is doing well to maintain connection. Are there a large number of errors (Routerstats will show that information on the status pages).
I don't think there is significant advantage in being synced at the top end of an IP Profile range rather than towards the bottom (5120 - 5664kbps for 4500kbps IP Profile) .
David
jelv
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Registered: ‎10-04-2007

Re: Lower sync than expected

If there are a large number of errors you probably don't want interleaving off. The BT system would be very likely to put up your target noise margin which would give you a lower sync.
jelv (a.k.a Spoon Whittler)
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Oldjim
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Re: Lower sync than expected

Try increasing the default noise margin using DMT
jojopillo
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Registered: ‎16-06-2010

Re: Lower sync than expected

HI Mav,
Quote
Would I get faster throughput if I synced at 5588 rather than 5120 even though the profile would remain the same at 4500?

Interesting question. I would imagine it may help to get you closer to the 4500. It does seem logical.
As for the number and the exchange check, they are anomalies and don't affect your service, so when I get a chance I will try to look further into that for you.
Jojo Smiley
WWWombat
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Re: Lower sync than expected

Quote from: spraxyt
I think the vertical bars in the sync speed graph are most likely to be missed data collection points (router busy with other tasks and slow to respond to routerstats) rather than loss of sync. Generally if sync is lost the sync speed changes on reconnection, and the dips are V shaped since it takes a finite time to reconnect.

In addition, Routerstats tends to colour the line differently if the drop to zero is because of a missed reading, rather than a true reading of zero. Unfortunately, the line is then coloured normally again when it returns from zero back up to the next (normal) reading - and because of the "V" shape, the lowest segment of the "going up" line can overwrite the lowest segment of the "dropping down" line. It can be hard to tell sometimes.
IIRC the usual colour of this "failed reading" is red, and I see your standard colour is kind-of-red, making it hard to distinguish. Perhaps if you reconfigure the graph to show a different colour it will help. As it stands, it looks like 3 of those drops are a slightly different shade.
I agree with the previous post - the noise margin looks uncomfortably low. Logic would suggest it is close to disconnecting, and that if it did so, it would resync at a lower speed and a higher noise margin.
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Re: Lower sync than expected

Quote from: Mav
Would I get faster throughput if I synced at 5588 rather than 5120 even though the profile would remain the same at 4500?

No. DLM is a conservative beast, and 5120 is quite a way above 4500. 5200 - 5300 would be preferable to give a bit of lee-way, of course, but there's no point in pushing for the max unless you can reach the next threshold at 5696.
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Mav
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Re: Lower sync than expected

Thanks for the replies and advice.
I have changed the colour for the sync speed plot and have added a recent graph.
I can't seem to get the status to show on the Summary page. I have added a jpg and have checked the settings nd can't fathom why I'm not getting the relevant details.
Never changed the SN directly before using DMT. Can I use the tool in RouterStats 6.5C? If so, what two values should I enter?
Thanks again.
Edit: Have downloaded what seems to be the latest version of DMT(9.01), entered the router's IP address (192.168.0.1) and the ID and password but get the message 'Error: can not identify modemtype. DMT version 9.01 for SpeedStream_4100/4200/5100/5200, Teledat_302/430'

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Oldjim
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Registered: ‎15-06-2007

Re: Lower sync than expected

Routerstats asks you to put in the default value and the new one you want but AFAIK it just works from the ratio so putting in 6dB and 9dB should increase it by about 3dB