Line or router faulty?

Recently I swapped out my trusty DG834PN for a DGN2000 as I need Wireless N.

The wireless signal is noticeably better but I now have another problem regarding the sync speed.

I am on an office package, 832kbps upload speed and the 834PN always sync'd at 832kbps with an 11db SNR.

Last week the internet went down and the downstream sync'd at the normal speed but the upload was 320kbps.

Strange, I have never known the upload speed to drop down from 832kbps before.

Just checked this morning and it is back down to 320kbps again.

Is it the router? Why would the upload speed drop but downstream be fine?

"Line or Router?" - I would start by trying your original router again and checking the stats...

They 834PN and DGN2000 sync at exactly the same speed. Right now the DGN2000 is sitting at 832kbps.

Few days later the DGN re-syncs and drops the upload speed down to 320kbps.

! When will be a few days later than "right now"? Can't you wait till then?

So cut and paste stats from the router,

a) Now

b) When it drops to 320Kbps

Then post both sets here and someone will have an opinion.

The stats are identical this is what I am getting at just the SNR for the upstream is 6db at 320kbps.

It drops down to 320kbps during the day which is strange as whilst my line is noisey, it will not drop during the day usually.

I don't understand what you are saying?

The DGN happily syncs at 832kbps and will sit there for days then all of a sudden it goes down to 320kbps but the downstream is not affected.

The upstream uses different (lower) frequencies than the downstream.

It sounds like you are getting a noise burst in these lower frequencies which cause the SNR to drop and a resync.

Any pattern about the times? A pattern may indicate the culprit.

It may be useful to know the full stats (i.e. attenuations, sync rates, SNR margin, for both up and downstream).

In reply to a post by wolvesmad:

The stats are identical this is what I am getting at just the SNR for the upstream is 6db at 320kbps

The SNR margin is just a part of the full stats, which, as shtu requested, you should post in order for someone to be able to sensibly comment.

Otherwise, you are just repeating yourself ad nauseam and unclearly at that.

Connection Speed 4672 kbps 832 kbps
Line Attenuation 50.0 db 28.0 db
Noise Margin 7.2 db 11.0 db

The connection speed is way down on what the line is capable of. The line has gradually got slower and slower over the years and all BT want to do is keep charging 120 pound.

It has been sync'd at that rate since Sunday night but it seems to drop around 10am-12pm.

It may or may not be related to a very similiar problem I'm suddenly having... for months been syncing perfectly happily with an upstream speed of ~1100Kbit w/ 12db SNR upstream and maybe 2-3 errors in 24 hours... last few days its struggling to get above 900Kbit and the SNR is anywhere from 0 to 6db with tons of errors resulting in the line dropping out every 2-5 minutes Upstream Bit error rate and HEC hits into the 1000s within 5 minutes - tried changing routers and microfilters with no change. I'm connected to the Yeovil exchange (Somerset). I'm about to get onto BT about it.

Edited by deleted (Tue 17-May-11 13:42:40)

bah... so I contacted BT with regard to upstream connection issues and what do they do? they put the downstream on a (lower) banded profile............. with no affect on the upstream.

When I have had upstram problems in the past they have been caused by a fault that created audible noise on the line.

Anything wrong that you could book as a voice fault?

(17070 Option 2)

Funny you should say that, no audible noise issues on the line but noticed today that every time someone recieved or finished a call the router loses sync and while they are on the phone the error rate climbs through the roof (Bit Errors: D: 0 /U: 22147, HEC: D: 1 /U: 556) just from a 4 minute call.

As I said I've tried changing microfilters, etc. so fairly certain its a line/exchange fault


EDIT: Oh <insert explicit here> just noticed today the upstream is in fastpath mode (usually interleave depth 4) so I'm guessing thats why its sensitive even to the phone line today - its been in interleave mode the last few days while I had this problem tho (but people using the phone wasn't affecting it).

Edited by deleted (Thu 19-May-11 15:21:40)