Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Chris P Duck]

Im still having problems with disconnections related to noise on my line. Ive been using a utility called "routerstats" to monitor my SNR which is showing random sudden nose dives is SNR which causes me to lose synch. Im investigating the cause of the noise (interference from my electrics etc).
What also is happening though which I dont understand is my SNR could be steady at 11 (target SNR is 12) then it suddenly will jump UP to 15 or 16 for a while then drop back to normal. What could cause that?
Heres a pic

[roseway]

Presumably some nearby source of electrical interference is being switched off periodically. Are there any factories working through the night near you?

[Chris P Duck]

no factories, fairly spreadout residential estate. As you can see on the graph, it was at 11 ish with a small blip up to 15 then down again. Then up tp 15 where its still at now,12 hours later. This is all after losing synch from 4800kbps to 3600. Could it be the exchange altering something which made the SN stay up high you think?

This is a fairly new thing as my IP profile has been fairly steady at 4meg for a while until this started a few weeks ago.

[roseway]

I wouldn't have thought that it's caused by anything going on in the exchange. The noise is a function of the quality of the line and any interference sources affecting it.

[kitz]

Difficult to say without seeing the whole course of a day - and then seeing if any patterns emerge over a period of say a week.

But from the graph you provide I would say that something is switched on during the day which is causing some sort of interference.  Then at 23.00 whatever it was is switched off and therefore your SNR Margin jumps up by 3dB.  For some reason it looks like it was off between 22.31 and 22.41.

The causes?  Central Heating Pumps and all the other usual suspects.  Could be something either in your property or a neighbours.  Monitor it over a longer period to see if you can see a more distinct pattern that may tie in with something.

[Chris P Duck]

I have been watching this for the last few weeks, there doesnt seem to be any fixed times for this occurance, it can happen during the day, early hours etc. We havent changed anything electrical ie CH pumps and we havent bpught anything recently so Im at a loss. Its been an absolute waste of time talking to BT India as usual Ive tried different face plates, filters, cables routers and I dont know what to do next

*edit* just had an idea- if i could run my router of some kind of battery source and monitor via my lappy, I could turn of my electic completely and see if it still hapens... I wonder how I could power my router...?

[mr_chris]

A 12v car battery would probably power most routers if you could wire it up appropriately?

[Chris P Duck]

what about ampage though? (Im not a sparky lol)

[soms]

You can get a 12v DC to 230v AC power adaptor in places like DIY and car accessory stores for around £20 i think which you can then plug the router PSU into.

Depending on the router you might be able to connect directly to car somehow. For example looking at Netgear PSU the rating is 12V DC 1 amp, which in theory a car battery could supply directly. Otherwise a cheap mains adaptor and then the usual PSU would work great.

Otherwise see if you can borrow or look for a cheap UPS. These are designed to keep a desk top PC running for a good few minutes so a router should run for ages.

*EDIT*

what about ampage though? (Im not a sparky lol)

Me neither. I seem to use that "compare electricity to water" idea. Volts is the size of the pipe and amps is the "pressure". Volts enables more current to be supplied, but the amps is the measure of current passing through so to speak.

Then watts is a measure of energy or something and is volts x amps, but when you monitor the power consumption of a 12V 1 amp router it is not actually 12 watts. I guess again this is the maximum power that can be supplied using the power supply and that the actual supply is dynamic to the requirements of the device.

(Please correct me if I am wrong before I do anything silly...)

[Floydoid]

Maplin do a good range of power supplies at a reasonable price.

[Chris P Duck]

cheers for the tips so far, i need to get this sorted as its really peeing me off now. Just dont have a great deal of spare time to spend on sorting this atm

[Chris P Duck]

A little update on this, the spikes seem to have stopped at the moment, but Im still getting disconnections in the evenings between 8pm-1am from my usual 4800kbps down to 3000 ish.
Im still monitoring the SNR which is steady at 11.5 all day then steadily drops to about 7 and then my synch drops. I thought it should only drop out when it gets down really low like 2 or 3 which was the point of having a raised target snr for problem lines IE a bigger allowance before your synch drops?
Also, if it does manage to hang on, it drops from 11db down to 7db from 8pm ish and stays there permanently. Is it supposed to go back to its target snr as the system goes less busy?

[roseway]

The target noise margin only comes into play at the time of syncing. After that it will go up or down according to line noise conditions. Certainly it would be expected to go back up during the day in your case, but some routers do seem to stick at the lower night-time level.

I don't think you've mentioned what router it is, but I'm a bit concerned that it drops sync when the noise margin is around 7 dB. You should be able to hold sync down to ~ 2 dB or less. Of course this might be a sudden burst of noise which causes sync to be lost so quickly that it doesn't get recorded. But I would be thinking about trying a different router.

[Chris P Duck]

I was on a BT home hub, then moved to my spare NG DG834gt. Had same problem on both. Could it be that more people have signed up to broadband at my exchange and my line is now suffering from more noise?

[roseway]

I don't think that other users add significant noise to your line. I suppose that there will be a small amount of crosstalk where they share a cable, but that wouldn't account for your erratic results. It's got to be electrical interference or a dodgy line.