ADSL2+ Upstream Noise Margin

[Adrian]

Hi All

Over recent days I have been experiencing an annoying and frustrating problem with my upstream noise margin which is all over the place resulting in frequent re-syncs. I do get periods of stable noise margin, but they tend to be short The interesting thing is that my downstream sync rate, while changing with each resync remains remarkably consistent and high, and I almost always re-sync with a 3dB downstream noise margin. Connecting the router to the test socket makes no difference.

I did a quiet line test from the the test socket using ye olde hard wired phone, and while there is a very feint level of background noise, I don't think it is enough to cause any problems and certainly no more than I have encountered before

I have also remade every single connection with a good quality IDC tool, but I didn't say that

As Is aid, the thing that I find particularly weird is that my upstream sync is unaffected by all this.

For the record I am using a Billion 7800N router, with the latest firmware. My current router stats are:

Up/Down attenuation 19.1/36.5dB
Up/Down Sync 817/12873
SNR (dB):        3.3(down)             13.0(up)
Attn(dB):        36.5(down)            19.1(up)

Mac Pro OS X 10.7.5

The attached screen grab give some idea of what is going on, the messy bit between 16:45 and 16:51 was me messing about with the line.

Any help much appreciated

Adrian

[RandomGeeza]

Hi All

Over recent days I have been experiencing an annoying and frustrating problem with my upstream noise margin which is all over the place resulting in frequent re-syncs. I do get periods of stable noise margin, but they tend to be short The interesting thing is that my downstream sync rate, while changing with each resync remains remarkably consistent and high, and I almost always re-sync with a 3dB downstream noise margin. Connecting the router to the test socket makes no difference.

I did a quiet line test from the the test socket using ye olde hard wired phone, and while there is a very feint level of background noise, I don't think it is enough to cause any problems and certainly no more than I have encountered before

I have also remade every single connection with a good quality IDC tool, but I didn't say that

As Is aid, the thing that I find particularly weird is that my upstream sync is unaffected by all this.

For the record I am using a Billion 7800N router, with the latest firmware. My current router stats are:

Up/Down attenuation 19.1/36.5dB
Up/Down Sync 817/12873
SNR (dB):        3.3(down)             13.0(up)
Attn(dB):        36.5(down)            19.1(up)

Mac Pro OS X 10.7.5

The attached screen grab give some idea of what is going on, the messy bit between 16:45 and 16:51 was me messing about with the line.

Any help much appreciated

Adrian

I have had EXACTLY the same issue... and have an engineer booked for today. Current line stats are as follows:

ADSL Link   Downstream   Upstream
Link Rate   9213 Kbps   444 Kbps
Line Attenuation   37.5 dB   21.8 dB
Noise Margin   9.3 dB   30.6 dB

I saw peaks on the Up of 6554 dB on Friday, whenever a phone was plugged into the socket (Test)... Here's my thread, with screen shots: http://www.idnetters.co.uk/forums/index.php/topic,30647.0.html

I wonder?

FYI OSX 10.8.3 (NetGear DGN2200v3 & DGN2000)

[Adrian]

I look forward to hearing what you BeeTee engineer finds (should that be Oooo Arrrrr engineer nowadays?).

[RandomGeeza]

I look forward to hearing what you BeeTee engineer finds (should that be Oooo Arrrrr engineer nowadays?).

It appears to have been the wiring leading from our junction box in the communal meter cupboard, to the outside street junction. Although my stats are not as good as I would have liked, or experienced pre issue.

Hoping my ten day training will see them correct themselves.

That is, if it doesn't all go t*ts again in the meantime. Keep us posted on your situation, findings, outcome. I am very interested to see how you go.

[Adrian]

Something quite simple then, but not obvious from the tests you and IDNet could perform. I glad you seem to have got it sorted out.

Right now my situation has returned to normal with near maximum upload and download sync speeds and a quiet phone line. I did rehash some of the wiring again this morning though that resulted in no immediate improvement but as the day wore on things steadily got better. I still see a 2.0-2.5 dB drop in upstream noise margin whenever I lift a phone handset when previously it would be 5dB or even more which would often result in an immediate resync. I will just have to wait and see.