Questions to do with Noise Margin

Pulse · 6 Aug 2007 at 02:08

for the past few months we have been having a lot of problems with out phone line and internet connectivity, normaly the lack of a internet connection and i think i have found the culprit. a lot of the time our noise margin is less then 10 which i have read to be pretty awful

6dB or below is bad and will experience no synch or intermittent synch problems
7dB-10dB is fair but does not leave much room for variances in conditions
11dB-20dB is good with little or no synch problems* (but see note below)
20dB-28dB is excellent
29dB or above is outstanding

questions i have is how does this noise level fluxuate (i.e. what would cause it to go up and down)?
would a phone being on dial tone increase the noise level?
is there any way i could improve this number?

Pulse · 6 Aug 2007 at 03:20

cheers for the reply, the only reason i ask about the phone is if my connection drops for severaly hours which it normally does daily, if i leave the phone on dial tone it will connect, but then obviosuly no-one can call as line will be engaged.

i've followed that guide before and it makes no difference to the state or my connections, just like plugging the router straight into the test socket doesnt gurantee a connection.

ADSL Link Downstream Upstream
Connection Speed 864 kbps 416 kbps
Line Attenuation 15.5 db 31.5 db
Noise Margin 14.8 db 14.0 db

thing is the noise started off as 7.something then when the page refreshed 5 seconds later it had doubled. any reason for that?

and yes meant to be on 8MB

edit: heres some more that i took last week

Date: 26th July 2007
Time: 19:17:56

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 160 /416
Line Attenuation(db) 52.0 /31.5
Noise Margin(db) 5.1 /13.0
Speed Test 138 /285

Date: 26th July 2007
Time: 20:38:51

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 1600 /416
Line Attenuation(db) 50.0 /31.5
Noise Margin(db) 22.0 /13.0
Speed Test 1371 /328

Date: 30th July 2007
Time: 01:54:01

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 1728 /416
Line Attenuation(db) 49.0 /31.5
Noise Margin(db) 25.6 /14.0
Speed Test 1486 /352

Date: 30th July 2007
Time: 21:54:52

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 416 /416
Line Attenuation(db) 49.0 /31.5
Noise Margin(db) 7.6 /13.0
Speed Test 353 /297

Date: 30th July 2007
Time: 22:21:22

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 5600 /416
Line Attenuation(db) 48.0 /31.5
Noise Margin(db) 10.8 /13.0
Speed Test 4822 /342

Date: 31st July 2007
Time: 19:02:17

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 832 /416
Line Attenuation(db) 50.0 /31.5
Noise Margin(db) 2.3 /14.0
Speed Test 722 /340

Date: 1st August 2007
Time: 22:26:59

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 512 /516
Line Attenuation(db) 52.0 /31.5
Noise Margin(db) 8.7 /13.0
Speed Test 442 /337

Date: 2nd August 2007
Time: 00:04:16

ADSL Link Downstream (Kbps) /Upstream (Kbps)
Connection Speed 288 /416
Line Attenuation 52.0 /31.5
Noise Margin 10.2 /13.0
Speed Test 248 /304

Pulse · 6 Aug 2007 at 12:14

thing is this has happened with 2 different isps, 2 different routers, 2 different sets of internal cabling (within the house), never the same any 2 days in a row, not weather controlled - so doesnt leave much else. im glad at least someone was able to diagnose it. but thing is a BT engineer has come out before and he couldnt find a fault.

Pulse · 6 Aug 2007 at 15:54

check out this other thread as this is what i have already tried

Pulse · 6 Aug 2007 at 21:41

when you say that my line attentuation shouldnt flux that much are you saying that with reference to the very 1st reading in the post above of 15.5 as i've heard that is a bug with the router that does sometimes happen or are you actually referring to the fact that it fluxuates from 48-52?

Pulse · 6 Aug 2007 at 22:50

you think that it may be poor electrical connection causing the changes in connection statistics?

Pulse · 6 Aug 2007 at 23:21

ok well thank you very much for the advice, ill get back to you once i have heard back from sky bout sending out a BT engineer, hopefully that will be tomorrow.

Pulse · 16 Aug 2007 at 18:32

right an update: Have contacted both Sky and BT, BT have sent me one email back saying that they will try to help, this was 2 days ago and have not heard from them since, i 1st contacted them a weekago. Sky on the other hand has not contacted me at all which i find appauling.

but i have some more symptons to add to my list, when our wireless phone is used it cuts off the internet connection although the line is filtered twice, once at the master socket and once in the kitchen socket, and yet it still does this. could the seconds filter be interfeering with the 1st?

i need to test to see if it does it with the wired phone in my room, so back shortly with another update.