Speeds

Started by Tanzanite, May 18, 2007, 21:29:12

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Tanzanite

#25
So what's causing it if it isn't the lead from the boxes as when I took them out the noise margin went to 6-7? The boxes themselves? Which are on standby at the mo and when I took them out/plugged back in.
Had the boxes about 2yrs though the Sky+ one a bit less as the first one blew up in a storm and it kept saying the telephone line wasn't connected.

Wireless connection, the router is about 4ft away at least from the sky box. Though in that little corner with the phone point I have a mini fridge, a/c unit, tv, stereo, thought he tv and stereo are further over by about 2ft. I know, not great but there's no where else the router will stretch too.

So I'll have to make do with the 9db noise margin, though it's a big improvement on 15db! lol

Rik

The modems in the Sky boxes are not very high quality, Eve, and seem to put a lot of noise on the line. That's why I recommend double-filtering - hopefully, what the first one doesn't get, the second one will.

QuoteWireless connection, the router is about 4ft away at least from the sky box. Though in that little corner with the phone point I have a mini fridge, a/c unit, tv, stereo. I know, not great but there's no where else the router will stretch too.

That's certainly not ideal, lots of electrical noise right on top of the phone connection. 9db is probably as good as it's going to get in terms of noise margin, I suspect, as you are probably picking up lots of spikes off both the fridge and air-con. Is there no other location/mains socket you could move them to?
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

Not really at the moment. I do need to change my tv and stereo round to a different place so I may be able to move the fridge a little. As for the a/c thats not an option as it's a professionally fitted one on the wall with a very short lead (hangs halfway down the wall) which I have to plug into an extension socket. The router plugs into the same extension socket and sits on a cupboard underneath but to the side of the a/c as far away as I can get it from all the electrical stuff.

Rik

The big thing to consider with the router is the path of the lead from the phone socket to the router. It should be well separated from mains leads where at all possible, and should cross them at right angles, rather than run parallel to them.

If you're connecting wirelessly, could the router move to a new location to improve its resilience?
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

I can't even have the router downstairs as there's no electrical socket anywhere near the phone point  >:(   Old house, not enough sockets, could maybe get a new one put in down there at some point though.

Will try and keep the router lead in a better position as you suggest.

Will keep an eye on the stats and any disconnection over the next few days now the noise margin is lower. Hoping I may sync at a higher speed too now. I disconnect the router over night because of the negative noise margin from middle of the evening.

Rik

You should start seeing a higher sync if the noise margin stays at 9db, Eve, though it may take a few days - the mysteries of DLM. Once you have the higher sync, then your profile should follow.
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

Thanks Rik, huge help  :) At least I found out what it was quicker this time lol

Have a Karma.

Rik

Glad to help and thank you, Eve. Of course, you could disconnect the Sky boxes until they start writing to you... Or, given you turn the router off overnight, try connecting the Sky boxes only during that period...
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

I've already had a letter from them once when I blocked my number from showing up when I rang out lol They might charge me if I did it again.

Though they tend to do that sort of thing at night so might be ok if they were in only at night. Not sure if I should risk it though.

Rik

The call backs are usually only at night, and they will write several times before charging you. I think it's worth a try, but then I'm not paying the bill. ;)
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

You're very welcome to pay it for me Rik  ;) :laugh:

Rik

Ah, but if I did it for you, Eve, there's another 498 forum members would want the same treatment. :)
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

Ah well, it was worth a try lol

When I first had broadband I didn't realise it was so complicated. I just plugged in my frog modem and surfed. It was surprising and frustrating to find that the slightest thing can affect speed. All AOL used to tell me to do is to defrag and change a few settings including lowering the hardware acceleration on the graphics card. It did help a bit but obviously it was just slightly helping the symptoms and not the cause. I've never had so much help since I came here, I love this place and IDnet of course  ;D I'm keeping Idnet a secret, not recommending it to anyone even though I'm desperate to lol I don't want it to turn into thousands and thousands of users and clogging up my speed and the support lol

Rik

The graphics card acceleration should not affect ADSL. I suspect that was more to do with the USB modem. If you still have acceleration reduced, go back to full speed and see if there are any problems.

It really is worth tweaking MTU & RWIN though - the sticky gives details. It's possible to get a 10% speed improvement by optimising these, especially if you're still running AOL's MTU setting of 1400.

I think we're all quite protective of IDNet, but Simon and Tim have a good track record for growing capacity ahead of demand - so the more people we can bring to the company, the better it could be for us all. :)

And yes, I do find the forum a special place...
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

This morning, despite nothing changing my noise margin is back up to 15 and sync speed is a little lower. Im fed up

Rik

It all points to noise pickup, Eve. See how it is tomorrow, I notice I had a re-sync last night - it seems to be a weekend thing for me, and noise always seems worse on a Sunday, possibly cross-talk.

If it's still acting up tomorrow, then it would be worth calling support and seeing what advice they can offer. Do bear in mind, though, that if they get an engineer out to check the line, you could be faced with a bill.
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

Thing is it seems to be the Sky boxes.

This morning I synced at about 5044, noise margin 15. I unplugged downstairs sky , noise margin fell to 9, unplugged my sky upstairs then rebooted router. When I rebooted it the sync speed was a little higher 5216 but the noise margin went back up to 15  ???Sky boxes still unplugged at that point.

So I plugged the sky boxes back in and then the noise margin fell again to 8 and seems to be fairly stable. Haven't rebooted router again but I bet it would go back to 15 if I did.

I have set up router stats so you can have a look. One from last night, where it starts going all over the place from about 7.30pm whats interesting last night is that normally it stays under 2 and goes to a negative number but then back to 2. Last night it went back up to 6 between it's dips to a negative number. No disconnection though.

One from this morning when unplugging sky and rebooting etc.

Just the noise margin in the graphs.

[attachment deleted by admin]

Rik

Hi Eve

We need to clear up a slight mis-communication here. Your target noise margin is 15db, so anything which reduces the figure is bad. When you re-boot the router, your connection will negotiate a speed with a 15db margin, what happens after that is down to noise, ie the more the noise that's being picked up, the lower your noise margin becomes.

Given what you say, it would appear that the Sky boxes are having a bad effect. However, the second graph has a massive amount of noise going on until about 9:25, then goes stable. Was that the point at which you plugged the Sky boxes in? If so, it would imply that your wiring is picking up noise when not 'terminated'. I have seen this happen, particularly if the filters are left connected. Was this the case?
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

#43
This is so confusing lol I thought that the more noise on the line then your noise margin goes up so logically if it goes down there's less noise.

The 2nd graph was when I started router stats this morning. You can see that the noise margin is about 12db. When it drops to 9db is when I unplugged the sky boxes, the pink colour is when I rebooted the router and it went back to 15db. I then plugged the sky back in and within 5mins of doing that the noise margin went to 2db then up to 8db and stayed there. I put the tv on half hour ago and the noise margin has been creeping up slowly to about 11/12db.

The filters were removed when I unplugged the sky boxes.

Lance

Think of it like this:

You have noise of 100
You get problems (ie re-syncs) when noise gets to 110.

You therefore have a noise margin of 10 (110-100).

If noise was to increase to 105 your new margin would be 5 (110-105).

This shows that an increase in noise will decrease your noise margin.

Hope this helps.
Lance
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

#45
Ok, but that still doesn't explain when I unplug the sky boxes and the tv is turned off the noise increases  Completely baffled.

Also why would a lower noise margin mean a higher speed if lower noise margin means there's more noise  ???

Tanzanite

Think I'll just give up and leave it as it is lol When I was first on MAX my sync speed was higher than it is now, not loads but enough to give me about another half to 1mg of actual speed.

Ideally I should move the router downstairs to get away from all the electric stuff near it but difficult when there's no plug socket anywhere near the phone point.

Rik

This is weird, Eve.

Back to terminology. Noise margin is the amount of signal in hand above the point at which the router could not detect the ADSL signal from the background noise. Back in fixed-rate days, that was likely to be 20db or more and, as a result, we rarely saw any disconnections. Max, otoh, starts with a target margin of 6db, and your router syncs with the highest speed it can achieve with that margin. If you pick up a lot of noise on the line, the margin will fall, possibly sufficiently to cause a re-sync. If this happens repeatedly, then the line management software starts to increase your target noise margin in steps of 3db, until it finds a level at which you have a reasonably stable connection. In the process, your sync speed and profile will decrease.

You have a target margin of 15db, hence you will see this figure immediately after a re-boot. However, something is causing your circuit to pick up large amounts of noise (at least 17db from the graphs). The fact that plugging in the Sky boxes seems to lower your margin I can understand, the fact that having them unplugged and the circuit 'unterminated' was worse I cannot understand - though I have seen it happen before. The fact that turning on the TV helps is a major puzzle. I'm beginning to wonder whether there is some interaction between your mains and phone circuits.

Did the ex-BT man check all the sockets and ensure there were no split pairs?
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.

Tanzanite

He did check both sockets, removed the ring wires and the extension socket upstairs was put in incorrectly. He did say something about split pairs but when he had finished he said there was absolutely nothing wrong with it now as he had sorted it all.

Rik

There's one more thing you could try, which is to power down (ie, unplug) both Sky boxes (also unplug from the phone line) and the TV. If the noise margin increases, plug the TV in, but don't turn it on. If the margin is still OK, plug the Sky boxes back in one at a time. If the margin decreases when you power any of these devices up, then they are radiating interference which is bring picked up by the phone line, the phone-to-router cable or the router itself. You might just improve things with a shielded ADSL modem lead - some people have had good results from them, others have not.
Rik
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This post reflects my own views, opinions and experience, not those of IDNet.