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Unexplained speed variations

deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Unexplained speed variations

I have spent several days doing a range of tests to try to discover why my overall speeds are low.
My router is a Netgear DG834 v3 (no wireless) and is plugged into the (BT installed) extension socket.
Here are the router statistics:
Speed:  5984kbps down  544kbps up
Atten:  31db down  7db up
Noise: 12db down 13db up.
Throughout the tests, these figures hardly varied. Attenuation did not vary at all.
When I plugged the router into the test socket behind the master socket faceplate, it gave these results:
Speed:  6432kbps down  576kbps up
Atten:  31db down  7db up
Noise:  11db down  13db up
I have also tried my SMC Barricade router. Here are its speed figures.
Speed: 3296kbps down and 640kbps up.
For comparison, the Netgear at this time, was giving speeds of 6176kbps down and 544kbps up.
I cannot improve on these results.
Keith
22 REPLIES 22
Anotherone
Champion
Posts: 19,107
Thanks: 457
Fixes: 21
Registered: ‎31-08-2007

Re: Unexplained speed variations

Hi Keith, as I remember you telling me that the SMC had been in the cupboad for a year or two, I don't know how reliable the results may be.
However it is appears to be showing consistency with the variable upload speeds as well as download.
Could you post the results from Weds 20th and Mon 18th?
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

Anotherone.
Here are the Netgear router stats you asked for.
Wednesday 20th.
Speed: 5568kbps down  544kbps up
Atten:  31db down  7 db up
Noise:  13db down 13db up
Monday 18th.
Speed:  6496kbps down  576kbps up
Atten:  31db down  7db up
Noise:  13db down  13db up
Yes, the SMC has been in a cupboard for over three years!
Thanks.
Keith
Anotherone
Champion
Posts: 19,107
Thanks: 457
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Registered: ‎31-08-2007

Re: Unexplained speed variations

Hi again Keith,
Bearing in mind there are no bell wire issues (sorted in the other thread), the only other results that I think may be of relevance are the Netgear results with the two different filters.
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

Would you like me to do two more tests tonight, one with the rat tail filter and one with the T filter?
Keith
Anotherone
Champion
Posts: 19,107
Thanks: 457
Fixes: 21
Registered: ‎31-08-2007

Re: Unexplained speed variations

I don't think there's much point Keith, the 2 from Thurs 21st will do.
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

Right, Anotherone, here they are.
'T' filter.
Speed:  6688kbps down  576kbps  up
Atten:  31db down  7db up
Noise:  10db down  13db  up
'Rat Tail' filter.
Speed:  6176kbps down  544kbps up
Atten:  31db down  7db up
Noise:  12db down  13db up
Keith
Anotherone
Champion
Posts: 19,107
Thanks: 457
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Registered: ‎31-08-2007

Re: Unexplained speed variations

Hi again Keith,
well apart from the varying download speeds and occasional drops, it's the upload speeds that suggest either a modem/router problem or an exchange linecard problem. It's strange that just two values are cropping up 544 & 576 with the Netgear though the SMC gave 640 when the correct value should be 448, so there's a few extra tones coming into play which shouldn't!
Although you've tried your SMC, as it's been out of commission for so long, it's advisable just to check this out with a loan router to confirm the problem.
Hopefully Jameseh can pick this up and help out with a loan router on Tuesday when the Comms team are back in.
James
Grafter
Posts: 21,036
Thanks: 5
Registered: ‎04-04-2007

Re: Unexplained speed variations

Hi Keith,
I've arranged for a loan router to be sent, which should be with you in the next 2-3 days.
Please do let us know how you get on.
Anotherone
Champion
Posts: 19,107
Thanks: 457
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Registered: ‎31-08-2007

Re: Unexplained speed variations

Thanks James.
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

James.
Thank you very much for sending me a router to try. I really do appreciate it.
I'll let you know how it goes.
Sorry for the delay in replying, but we were out all day yesterday.
Keith
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

Thank you very much, James, for organising the loan of a Speedtouch 585 router for me. It arrived very promptly.
I've done some tests with it and here are its statistics.
Speed:  7616kbps down  672kbps up
Atten: 29.0dB down  16.5dB up
Noise:  12dB down  13dB up
In comparison, here are the latest statistics for my Netgear DG834.
Speed: 6336kbps down  544kbps up
Atten: 31dB down  7dB up
Noise: 10dB down  13dB up
During all the extensive tests I have conducted over the past week or so, using the Netgear DG834, the speed varied between 6048 - 6848 (usually around 6100 and 6300) down, and 544 - 576 up. The attenuation was constant, and the noise varied by a maximum of 2dB both up and down.
During the morning, the PlusNet speedtester shows I have a download speed of 812kB/s and an upload speed of 70.8kB/s.
(I have been trying regularly for many months to access the BT speedtester, but it is permanently busy.)
Using the Speedtouch, during a morning I can download  files at 790+kB/s, so they are downloading at almost my maximum speed. With the Netgear, they download at around 450kB/s.
PlusNet gives me a profile of 8000.
I hope that I have explained the situation clearly!
Any comments will be appreciated,as my knowledge of routing is very limited!
Many thanks.
Keith
James
Grafter
Posts: 21,036
Thanks: 5
Registered: ‎04-04-2007

Re: Unexplained speed variations

What's interesting is that on the Thomson, the noise margin is higher, but gives a better downstream sync speed, which doesn't make that much sense Smiley
itsme
Grafter
Posts: 5,924
Thanks: 3
Registered: ‎07-04-2007

Re: Unexplained speed variations

But the attenuation is less.
deekay
Grafter
Posts: 209
Registered: ‎05-08-2007

Re: Unexplained speed variations

I have just taken the Thompson statistics again.
Exactly the same, except that the 'down' sig/noise has gone to 12dB.
The Netgear statistics I gave, were taken this morning and are very similar to the ones I have got each time I take them.
Thanks
Keith