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noise margin

hitachi
Grafter
Posts: 343
Registered: 05-04-2007

noise margin

Hi
A couple of weeks ago my exchange was upgraded,since then my noise margin has been between 7.5 and 8,am I right in assuming this should be more like 6.
If this is the case is this something plusnet can change.
Protocol: G.DMT2+ Annex A
Downstream Rate: 18769 kbps
Upstream Rate: 1176 kbps
Channel: Fast
Current Noise Margin: 7.9 dB (Downstream) 6.1 dB (Upstream)
Current Attenuation: 4.2 dB (Downstream) 3.8 dB (Upstream)
Current Output Power: 11.1 dBm (Downstream) 12.3 dBm (Upstream)
I have had 636 errored seconds and 853 uncorrected blocks in the last ten days,so the connection is fairly stable.
Cheers.

6 REPLIES
Community Veteran
Posts: 4,854
Thanks: 121
Fixes: 24
Registered: 14-07-2009

Re: noise margin

Quote from: hitachi
my noise margin has been between 7.5 and 8,am I right in assuming this should be more like 6.

Not if you live next door to the telephone exchange as you appear to, judging from the amount of attenuation.
hitachi
Grafter
Posts: 343
Registered: 05-04-2007

Re: noise margin

Opposite side of the road. Smiley
I could understand that if I was getting full speed synch,but I am not.
Superuser
Superuser
Posts: 9,583
Thanks: 958
Fixes: 55
Registered: 06-04-2007

Re: noise margin

Are you really wanting the squeeze the last bit of downstream performance from your connection? Assuming your target noise margin is 6dB (as seems likely) restarting the router when the current value is around 8dB might give you a slightly higher sync speed.
However, left to its own devices the DLM might decide to try a 3dB target noise margin, perhaps after 14 days, which might achieve a little more. Basically it's your call - though my inclination would be to give the DLM a chance.
David
David
Community Veteran
Posts: 4,854
Thanks: 121
Fixes: 24
Registered: 14-07-2009

Re: noise margin

Quote from: hitachi
I could understand that if I was getting full speed synch,but I am not.

That's really the issue, isn't it.  What you would expect with such a low attenuation is the maximum sync speed and quite a high noise margin.  Have you tried the standard plug-the-router-into-the-test-socket procedure for debugging speed issues?
hitachi
Grafter
Posts: 343
Registered: 05-04-2007

Re: noise margin

Unfortunately I have no master socket,the line in goes to a small junction box then onwards to a standard socket.
@ spraxyt, Not that bothered really,just curious.
hitachi
Grafter
Posts: 343
Registered: 05-04-2007

Re: noise margin

I found the problem,the firmware on my ex BT 2700 hgv does not go below 8 dB,so a change is in order.