Routerstats SNR wave

gingerjedi · May 14, 2008, 13:10:47

Does anyone know why the graph would look so different over a period of just a few days?

The first one has very obvious flat peaks and troughs, the second is comparatively smooth and the third is very jagged.

I was just wondering if there was an expert out there who understands why this would be?

I'm on standard ASDL home 2000 BTW.

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gingerjedi · May 14, 2008, 13:11:38

Only 2 attachments per post $:-\$

Third:

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Rik · May 14, 2008, 13:17:11

Change the scale of the graph to run from 0db to 16db, this will give a better picture of what is going on. Personally, I see little difference between 1 & 3, both show lost of noise. The second graph seems to reflect a quieter day.

gingerjedi · May 14, 2008, 14:15:19

My SNR often hits 21-22dB so 16 would be out of range, I'll set it to 24.

On the first graph their seemed to be something limiting the maximum SNR to 12dB, this is something I had never seen it do before?

Rik · May 14, 2008, 14:21:29

I wonder if you got switched to a Max product? Otherwise it would suggest a general level of noise depressing the margin at all times.

gingerjedi · May 14, 2008, 14:26:30

I was on ADSL Max when I was with Tiscali (spit!) which was absolutely useless so when I moved to IDNET I requested a standard ADSL Home 2000 package, is there a chance something wasn't switched over properly? I l always sync at 2272kbps up and 288kbps down which is what I would expect.

Rik · May 14, 2008, 14:29:35

No, that sync is correct for a fixed-rate product. I was just wondering if the DSLAM had had a little excursion for you - did you happen to check your sync speed during the 12db period?

Looking at the amount of noise you do get, though, I think fixed rate is definitely a better option for you.

gingerjedi · May 14, 2008, 14:39:36

I did! It hadn't changed form the usual.

I accept I am out of spec for a 2meg product (47dB attenuation) but I just don't understand why the noise and line drops are so random? Weather and time of day seem irrelevant.

I usually give up trying to get it fixed but every few months it gets on my nerves and try and get to the bottom of it again, this is probably the 4th or 5th time I've looked into it.

Everytime I get BT involved the problem clears up.

Rik · May 14, 2008, 14:41:29

A bad joint would make sense. If they re-make it, it would clear the problem for a while, but if they don't tackle the underlying cause, eg a leaking duct, it will return.

gingerjedi · May 14, 2008, 15:00:23

Sounds about right, the last time the engineer came he said he had done something down the road but I didn't know if he had or he was just fobbing me off??

The strange thing is we can have days of heavy rain and it will be fine, likewise we've had some hot days recently but it's only played up on 1 or 2 of them?

I'm sure theres a guy down the exchange who keeps spilling coffee or something.

Rik · May 14, 2008, 15:10:45

It would be worth keeping a weather diary to see if that gives any pointers.

Sebby · May 14, 2008, 18:06:43

Out of interest, what router do you have?

gingerjedi · May 14, 2008, 20:14:35

Netgear DG834GT, I've also got a Belkin F5D7633-4 which is very good but no mater what I try I can't co figure routerstats to work properly with it?? I've also tried a Linksys SuperG which was OK but a pain to configure my wife's VPN requirements and there was no SNR readings at all.

Overall the Netgear is the easiest to use but the Belkin is the most stable, they both drop sync though.

Sebby · May 14, 2008, 22:26:48

I'm not 100% what chipset that uses, but I think it might be the Broadcom, in which case my theory falls down.

MoHux · May 15, 2008, 15:06:07

Hey Ginger, a l o n g time ago in another incarnation

, I used to know a bod by the name (IIRC) of 'Phantom Flan Flinger' ------- wouldn't be you would it?

Mo

Rik · May 15, 2008, 15:38:18

I really have to know how you made that leap of logic, Mo.

drummer · May 15, 2008, 17:18:16

Quote from: Rik on May 15, 2008, 15:38:18
I really have to know how you made that leap of logic, Mo.

The ability to retain trivia helps (mea culpa).

http://www.amazon.co.uk/Phantom-Flan-Flinger-T-Shirt-Black/dp/B000UVZBEY

gingerjedi · May 15, 2008, 17:20:59

Quote from: MoHux on May 15, 2008, 15:06:07
Hey Ginger, a l o n g time ago in another incarnation , I used to know a bod by the name (IIRC) of 'Phantom Flan Flinger' ------- wouldn't be you would it?

Mo

Sorry... Not me guv'.

Rik · May 15, 2008, 17:26:05

Quote from: drummer on May 15, 2008, 17:18:16
The ability to retain trivia helps (mea culpa).

http://www.amazon.co.uk/Phantom-Flan-Flinger-T-Shirt-Black/dp/B000UVZBEY

Some memory store you've got there, Drummer, though I'm not sure that "The best of Tiswas" isn't a contradiction in terms.

MoHux · May 16, 2008, 11:43:39

Quote from: Rik on May 15, 2008, 15:38:18
I really have to know how you made that leap of logic, Mo.

No leap Rik.

They both used the same Avatar.

@Gingerjedi: Thanks for taking time out to reply!

@Drummer: I really didn't know about the T-Shirts. The chap I knew was several years ago!

Mo

Rik · May 16, 2008, 13:44:40

Thanks for that, MO, I thought you were using your psychic powers again.

gingerjedi · May 16, 2008, 16:07:51

I've just ordered one of these, I don't know if it will make much difference but it's worth a try over the standard flat ribbon cable I'm using now, saying that... I do wonder why I bother shielding the last 7 feet when BT doesn't give a toss about the other 7,000. $:-\$

I've just seen the same one on the PC World site: linky £18.94 delivered compared to Play's £2.99! I don't think I've ever seen such a massive disparity in prices.

Rik · May 16, 2008, 16:12:00

I use one, it seems to be better than the supplied cable, but that's not science, just observation.

The big difference should come from the twist, which flat cables don't use and BT's cables do. The shielding may add a bit more.

gingerjedi · May 16, 2008, 16:50:02

I don't expect it to make much difference but having good internal wiring along with top notch filters and cables gives me some reassurance that I have done the best I can at my end.

Rik · May 16, 2008, 16:51:31

That's it, Ginger, we do the best we possibly can, then it's up to BT to deliver.

Sebby · May 16, 2008, 17:58:47

Quote from: gingerjedi on May 16, 2008, 16:07:51
I've just ordered one of these, I don't know if it will make much difference but it's worth a try over the standard flat ribbon cable I'm using now, saying that... I do wonder why I bother shielding the last 7 feet when BT doesn't give a toss about the other 7,000. $:-\$

I've just seen the same one on the PC World site: linky £18.94 delivered compared to Play's £2.99! I don't think I've ever seen such a massive disparity in prices.

The only thing I'd say is that 2.1m is quite long, and if you don't need that length, I'd strongly consider getting one of ADSL Nation's instead (0.5m or 1m). As well as it being shielded, length is one of the most important factors.

Rik · May 16, 2008, 17:59:59

Quote from: Sebby on May 16, 2008, 17:58:47
length is one of the most important factors.

Or so I've been told.

Sebby · May 16, 2008, 18:01:30

As I finished writing it, I thought someone would pick up on that, but I was too lazy to change it.

Rik · May 16, 2008, 18:07:43

You didn't have to wait long, did you.

Sebby · May 16, 2008, 18:16:56

I wouldn't want it any other way.

gingerjedi · May 23, 2008, 14:53:40

After nearly a week of getting graph 1 I'm back to graph 2 again.

I'm on ADSL home 2000 but my attenuation is a steady 47db which I know is out of scope, rather than have my profile dropped to 1meg is there a halfway house of say 1.5meg? Is this likely to improve things?

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Rik · May 23, 2008, 14:58:09

Ouch, that is a lot of noise there!

There is no 1.5Mbps service, it's 512, 1M or 2M with fixed rate. You're in a difficult position, because BT's reaction is likely to be to move you to 1Mbps if a fault is raised. Do you plot attenuation as well, does that show any movement in line with the noise?

gingerjedi · May 23, 2008, 15:14:40

Attenuation never changes, I've had the SNR line almost completly flat (I didn't save a pic) so I have no idea what's caused this?

If I do go to 1meg would this guarantee less noise? I suppose if the problem is still there at least I can get BT to sort it out as I will be within spec, then I can get the nice people at IDNET to put it back up again.

Rik · May 23, 2008, 15:16:29

The noise won't be reduced by going to 1M, but the line should be more stable. OTOH, if it's not, BT could decide the line is incapable of supporting ADSL - it's really a case of finding out what is causing the noise. The reason I asked about attenuation was that it was a long shot that the noise spikes were linked to high attenuation, which would indicate a line fault.

Steve · May 23, 2008, 15:24:56

For my own interest. Why is there such a difference in margin?The first graph shows a constant high margin which correct me if I am wrong is typical of a fixed rate service, it them seems to drop to six with noise which would be typical would it not be of a max dsl line

gingerjedi · May 23, 2008, 15:26:40

It's definitely something outside of my house between me and the exchange is it worth reporting cross talk to get the pair swapped as suggested in another thread? This has been happening off and on for over a year now.

As for the difference in margin.

Rik · May 23, 2008, 15:30:05

Quote from: stevethegas on May 23, 2008, 15:24:56
For my own interest. Why is there such a difference in margin?The first graph shows a constant high margin which correct me if I am wrong is typical of a fixed rate service, it them seems to drop to six with noise which would be typical would it not be of a max dsl line

Agreed, Steve, there does seem to be some Jekyll and Hyde behaviour going on.

Rik · May 23, 2008, 15:31:40

Quote from: gingerjedi on May 23, 2008, 15:26:40
It's definitely something outside of my house between me and the exchange is it worth reporting cross talk to get the pair swapped as suggested in another thread? This has been happening off and on for over a year now.

It won't do any harm to try. You might want to check with Lance on what he said, but the usual approach to take is that you can occasionally hear other people's conversations on the line, albeit faintly.

Lance · May 23, 2008, 15:45:27

Quote from: Rik on May 23, 2008, 15:31:40
It won't do any harm to try. You might want to check with Lance on what he said, but the usual approach to take is that you can occasionally hear other people's conversations on the line, albeit faintly.

Those were almost my exact words, Rik

I made the point that it was intermittent

Rik · May 23, 2008, 15:48:13

Yes, always give them an intermittent to chew on - it leaves them feeling a pair swap will be easier.

Sebby · May 23, 2008, 17:25:58

Good luck. It'll be interesting to hear whether this cures it. BT's cabling really does need a complete overhaul.

gingerjedi · May 27, 2008, 12:17:40

Its been like this ever since I last posted, the urgency goes away when I calm down and I don't want to risk losing ADSL alltogether!

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Rik · May 27, 2008, 12:25:36

It's frustrating - that's what the graph should look like, that's what it can look like, so what is causing the problem. You need a BT engineer to move in with you until it starts up, and then leap into action.

Sebby · May 27, 2008, 19:19:41

Now there's an idea, Rik...

Rik · May 27, 2008, 19:26:37

If only...

Sebby · May 27, 2008, 19:27:19

I reckon they'd still make excuses, though.

Rik · May 27, 2008, 19:28:09

Of course they would, but they'd be an altogether better class of excuse.

Sebby · May 27, 2008, 19:29:28

It would be like "didn't you just close a door? That's a well known cause of re-syncs."

Rik · May 27, 2008, 19:30:01

Sebby · May 27, 2008, 19:31:56

Thanks, Rik.

It's nice when the likely truth of the matter is funny.

doc_holiday · May 27, 2008, 20:07:08

Quote from: gingerjedi on May 16, 2008, 16:07:51
I've just ordered one of these, I don't know if it will make much difference but it's worth a try over the standard flat ribbon cable I'm using now, saying that... I do wonder why I bother shielding the last 7 feet when BT doesn't give a toss about the other 7,000. $:-\$

I've got one of these. I can't tell you if it was worth it or not, because I never tested it with a cheapo cable. At least it looks more impressive than the flimpsy white ones!

That said, my line noise has crept up in the last few months, so I'm replacing the wall filter and am making a few changes to the house wiring. From my point of view, using good leads, filters and keeping your lines in good nick can only help.

Sebby · May 27, 2008, 20:28:00

Absolutely, plus, unless there's a clear fault external to our properties, it's the only thing we can do.