Upstream Noise Margin... 6553 db!!!

[hells bells]

I've just had a bit of a drop in service so we thought we'd check the router stats. I put it on a 2 second poll. The downstream was rather steady and stayed pretty much the same whereas the upstream noise margin went absolutely mental! From a steady 4.5-5.0 db to 6553 db!! It only did it for a 2 second interval but the connection was unusable at the time.

Router stats at 22.46.

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 55612 74747 0 2162 7854 03:00:35
LAN 10M/100M 75486 58897 0 8051 2318 03:01:38


ADSL Link Downstream Upstream
Connection Speed 1479 kbps 563 kbps
Line Attenuation 43.0 db 22.9 db
Noise Margin 14.1 db 5.3 db

Just for info, last Friday IDNet put some sort of stabilization tool on my line as it was still very flaky on the 9th day of my training period.

Any help or advice would be greatly appreciated! 

[hells bells]

Still getting faster speeds though (and this IS fast for my line!!) so I'm still friends with IDNet! 

[Steve]

I've no idea although the upstream margin is relatively immune from noise as its transfers at a lower frequency.

[hells bells]

I have set it so that the router polls the stats every 2 seconds and it seems to leap around anywhere from 1 db to 7 db (and 6553!!)
The other noise levels are pretty constant and the line attenuation is constantly 43.0 ish down and 22.9 up.

We just thought we'd have a look while it was having "a do" and that was the only that was really playing up in the router stats.

Thanks for your advice anyway!

[Steve]

I think possibly the 6553 could be when it dips below zero and it cant report a minus number.

[hells bells]

You are probably right.
It seems to have calmed down again now. Just as I'm going to bed! Typical!

Thanks for your wisdom!
Helen.

[Rik]

I'm with Steve, Helen, that's either a disconnection (ie there is no margin to report) or a negative figure. Given the connection was unusable at the time, I lean towards the former.

[hells bells]

Thank you Rik!

I knew that it wouldn't actually be 6553 db. Could you imagine?! It would sound something like a nuclear explosion! 

[Rik]

Have you checked your router for meltdown? 

[Steve]

Thank you Rik!

I knew that it wouldn't actually be 6553 db. Could you imagine?! It would sound something like a nuclear explosion! 

Or my mother on a landline.

[Rik]

 

[hells bells]

  @ Steve!

[esh]

I think Steve is right here, since 65535 is the maximum limit of a 16-bit unisgned variable it is a fair bet that this is an attempted display of something like -1, likely meaning "I have absolutely no idea" (an unsigned variable cannot be negative). Or it could be an amazing coincidence. Either way, since dB is logarithmic, 10^655 would be a rather wild noise margin!

[Steve]

Thanks Esh 



I'd already done the maths,I just didn't quite know how to write it down 


PS

[hells bells]

Thank you for all of your help everyone. I've no idea with all of this technical stuff but my boyfriend (who is technically minded) is nodding away so you must be doing something right! 

[Rik]

We must have slipped up then, Helen.

[Lance]

Or he is just pretending!!! 

[Rik]

Good point.