line attuation and sync speed

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27 Aug 2006
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758
Location
bideford/exeter, devon
my attuation is 27db downstream and I sync at 4608 on pipex...should this be more?

thanks
 
Yes. Should be good for 8128 sync. What is your noise margin? Have you got a filter on everything connected to the phone line, including the modem and any sky boxes?
 
no sky boxes - line margin is very bad ive been getting drop outs and resync a lot on this connection due to it.


Downstream Upstream
SNR Margin (dB): 4.0 22.0
Attenuation (dB): 27.0 23.0
Output Power (dBm): 11.9 19.3
Attainable Rate (Kbps): 4640 1040
Rate (Kbps) 4608 448
K 145 15
R 0 0
S 1 1
D 1 1

ive just got a router with a modem built in - usr9105 wired router. Ive got a filter attached to the master socket downstairs which the router is plugged into.

thanks
ghgh
 
You should be getting full speed, have you tried plugging into the test socket, behind the faceplate on the master socket?

adslattvsspeedchartbs0.jpg
 
With an SNR margin like that and your modem connected to the master socket, you're getting as much as you're going to get - guesstimating with the attenuation is as much use as reading tea leaves.

Are there any extensions hard-wired into the master socket?
 
there areant any extensions hard wired to the master socket as such, but there is an extension that comes from somewhere along the line....Ive put two filters in it as it has two phone points but the snr margin got worse.

i cant plug the router into the test socket as its bts properly apparently.
 
Generally you can get a higher speed if your SNR is above 6. It works out that you should be able to get about 2mb higher per 6-8db that your SNR is above 6. If your SNR goes below 6 your line can become unstable. So for example if you are connected at 2mb with an SNR of 14 you should be able to connect at 4mb easily. Ideally your SNR should be around 6.1 so that you are getting the most out of your line.

Since your attenuation is good, I would recommend you contact your ISP and find out why your SNR is so low. It may be interference in/around your property though. Christmas lights, microwaves, etc can cause this.
 
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Just remove the bottom half of the BT master socket and plug the modem directly into the test port behind the now removed bottom half. If the SNR margin improves then it would suggest that you may have a problem with either the wiring beyond the master socket or maybe a device that's plugged in.
 
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