Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[eric_the_viking]

The attached SNRM pattern started three days ago after the (Netgear) router re-synched from 2368kbps to a lower download speed for some reason.
 
It is the same using a different (Speedtouch) router (which it is on at the moment); and I have tried it with all house power off, running on the UPS but it doesn't change.
 
The pattern obviously prevents the router (either type) returning to the previous satisfactory download speed of 2368kbps.
 
Any ideas please?

Eric.

[attachment deleted by admin]

[jeffbb]

hi and welcome

It looks as if there is something switching on and off every couple of minutes .
quote re-synched from 2368kbps to a lower download speed for some reason.

did you have multiple re synchs ?. I guess the reason your synch rate has dropped is that your Target SNR looks as if its 15db. Did you notice what it was prior to the resynch ?
can you post your full stats ?
Regards Jeff

[eric_the_viking]

Thanks for the reply.

The DG834v4 had been running for a month or so at 1920kbps with a target SNR of 15. I reloaded the router using DGTeam f/w and it came back at 2144/15. As this still failed to get my target 2Mb back I set the SNR Percentage to 50% and it resynched at 2496/6. Shortly after it went to 2272/9, and that held long enough to get my IP Profile up to 2Mb.

Lo and behold, a few days later it changed back to 1920/12, which point I tried a reboot (dropped to 1856/7.4), followed by the change to the Speedtouch 546v6, which came up at 1600/12!

Hastily back to the DG834 and up came the pattern; but running at 2368 - for 3 minutes! It then dropped to 1920/6, so I reset the SNR Percentage to 100% and got 1664/15! Reloaded Netgear f/w - went to 1440/15, still with the pattern.

So back to the Speedtouch for comparison, and that's where it's been since, running at 1632.

(Are BT punishing me for daring to set my own SNR?!)

I haven't got a handle on how to get the stats out of the Speedtouch yet, so I'll need to revert to the DG834, where I know my way around a bit better; but that will be later today after my working at home, hence use of the internet, has finished!

Eric.

PS So I finished typing this, set RouterStats going, went and washed up the breakfast dishes, came back up and - lo and behold - it's running 1632kbps at a dead flat SNRM of 8.5  !!! Whatever it was has switched off over night. (I really do wonder about BT .........)

Mind you, that's a real crap speed and margin, so I think it's back to the DG834; but I'll put the DGTeam f/w back in beforehand.

[roseway]

You're not really doing yourself any favours by swapping about so much. It will probably have encouraged BT's DLM to see your connection as unstable, and keep the target noise margin high as a result. It's pretty clear that the DG834 with DGTeam firmware is the best option on your line, so I would put that back and leave it with the noise margin slider in its default position. Then you need to find out what is causing the repetitive changes in the noise margin.

As Jeff said, it must be something which is switching on and off at a regular rate. Is there anything in your home which might be doing this? Are there any industrial premises nearby? Could you check with the neighbours whether they've got anything new recently which might do this? It's so consistent that it ought to be possible to trace a cause.

One last point, the figure which you didn't mention among all the stats was your downstream attenuation. If you could let us know that it would give us an idea about what speed your line should be capable of.

[waltergmw]

Assuming this is a new phenomena, as well as a new piece of equipment being installed, another cause could be something which has been in use for a long time, but is now struggling; tripping in and then out again.

Kind regards,
Walter

[eric_the_viking]

Hi Roseway,

The swapping was carried out over a period of several days - I try to keep it to one or two changes at a time.

I switched all the mains off in my home (PC etc running on UPS) and the pattern persisted.

The closest neighbours were not aware of any changes that may have been causing noise.

The Speedtouch is still in and running and the current Stats (with SNRM dead flat at 8dB) are as follows:-

Uptime: 1 day, 14:55:28
 
Modulation: G.992.1 annex A
 
Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,632
 
Data Transferred (Sent/Received) [KB/KB]: 0.00 / 0.00
 
Output Power (Up/Down) [dBm]: 11.5 / 17.0
 
Line Attenuation (Up/Down) [dB]: 31.5 / 60.0
 
SN Margin (Up/Down) [dB]: 17.0 / 8.0
 
Vendor ID (Local/Remote): TMMB / TSTC
 
Loss of Framing (Local/Remote): 0 / 0
 
Loss of Signal (Local/Remote): 2 / 0
 
Loss of Power (Local/Remote): 0 / 0
 
Loss of Link (Remote): 0
 
Error Seconds (Local/Remote): 9 / 0
 
FEC Errors (Up/Down): 0 / 2,458,732
 
CRC Errors (Up/Down): 0 / 192
 
HEC Errors (Up/Down): 0 / 170

I'm sure they will mean something more to you than me .................... especially the FEC Errors.

Thanks,

Eric.

[roseway]

Don't bother about the FEC errors. They are precorrected errors (i.e. they don't require retransmission of the data) and are a consequence of having interleaving enabled.

Your attenuation is quite high at 60 dB, so unfortunately your connection is going to be vulnerable to interference. If everything is working well you should be able to get an IP profile of 2000 kbps. I think that, apart from trying to locate the source of the interference, it would be well worth spending some time doing all you can to make sure that your own wiring setup is as good as you can make it. There's a lot of good advice here and in the associated pages.

[eric_the_viking]

Hi Eric 1 (must be that way round!),

Thanks for the help and advice.

After much swapping around and experimenting over the past years I now have the DG834 connected via a standard ADSL cable (consistently slightly faster than an ADSLNation Pro+) to an ADSLNation XTE-2005 faceplate filter with no telephone extensions connected from behind (so equivalent to that old demand - plug your filter direct into the test socket - but even now darling ISP can't comprehend that!). Telephone cable was re-routed ages ago to get rid of interference from telephone calls.

I don't think I can do much more!

I'm going back to the DG834 shortly, and next time the noise pattern chages I won't be panicked into thinking something has gone wrong here!

My ISP and BT refuse to believe that I can get 2MB, even though they can see I've had it running at 2.5 for a few months!

Cheers,

Eric 2.

Ha - just put the DG834 back and it's resynched at 1408/12!! Wonderful

I give up - I'll just leave to do it's own thing I think!

[roseway]

I don't think I can do much more!

No, you've made it as good as it can be made.

[jeffbb]

Hi as a matter of interest what is your output power ?
regards Jeff

[eric_the_viking]

Hi Jeff,

Quite a few things have changed from the Speedtouch -

Downstream Stats:

Noise Margin:     11.4   dB
Connection Rate:  1408  Kbps
Line Attenuation: 62.0  dB
Power:            16.9  dBm
Max Rate:         1536  Kbps
 
SF:               1087310
SF Errors:        21
Reed Solomon:     18484274
RS Corrected:     1160
RS Un-Corrected:  85
HEC:              14
Errored Seconds:  13
Severe ES:        0
Interleave Depth: 8

Upstream Stats:

Noise Margin:     17.0  dB
Connection Rate:  448   Kbps
Line Attenuation: 31.5  dB
Power:            12.3  dBm
Max Rate:         896  Kbps
 
SF:               1089625
SF Errors:        8
Reed Solomon:     18523625
RS Corrected:     16
RS Un-Corrected:  0
HEC:              3
Errored Seconds:  0
Severe ES:        0
Interleave Depth: 8

Blowed if I can understand what is going on!

Eric.