50% Sync Rate Drop

MisterW · Jul 19, 2010, 18:25:22

QuoteOK, this is getting strange now. BT Availability Checker say that the maximum estimated speed of my line is 2.5Mbit - i.e. what I'm getting. I was getting 8Mbit last week. What the hell has happened?!

I've seen something like that before. I believe that the availability checker works in 2 ways to get an estimate of line speed , if the line doesnt have broadband active it bases the estimate on either distance or attenuation from a line test, if broadband is active then it uses the currently achievable speed.

I would have thought that in your case if you have previously been synching continuously at 8128k then your current speed will be well below the FTH ( Fault Threshold ) for your line, and therefore BT must accept ( once you've eliminated all your wiring and equipment ) that its a fault.

Rik · Jul 19, 2010, 18:30:56

The problem is that BT can redefine the FTR at any time, and do. The most important thing for Netgem is to eliminate his equipment from the equation. Then, it should be safe to chuck it at BT without a risk of charges.

MisterW · Jul 19, 2010, 18:33:39

QuoteThe problem is that BT can redefine the FTR at any time, and do

I thought it was set during the 'training period' and unless there has been an SNR reset to restart the training ( which there doesn't appear to have been here ) it should not be reset.

netgem21 · Jul 19, 2010, 18:35:03

Just thinking, shouldn't my noise margin for upload be 6db? Seems a bit high at the moment...

Rik · Jul 19, 2010, 18:35:33

Quote from: MisterW on Jul 19, 2010, 18:33:39
I thought it was set during the 'training period' and unless there has been an SNR reset to restart the training ( which there doesn't appear to have been here ) it should not be reset.

I've met cases where they have simply decided that the line has degraded and so adjust the FTR, but you're right, it should only happen after a new training period.

Rik · Jul 19, 2010, 18:36:27

Quote from: netgem21 on Jul 19, 2010, 18:35:03
Just thinking, shouldn't my noise margin for upload be 6db? Seems a bit high at the moment...

No, it will depend on the line attenuation. Only with ADSL2+ does the u/s margin have a target of 6db.

netgem21 · Jul 19, 2010, 19:00:55

I've just done a factory reset of the router - here are the new statistics.

[attachment deleted by admin]

Rik · Jul 19, 2010, 19:04:54

Can you check to see if there's a firmware upgrade available?

netgem21 · Jul 19, 2010, 20:07:07

Quote from: Rik on Jul 19, 2010, 19:04:54
Can you check to see if there's a firmware upgrade available?

Yep, it's the Netgear DG834v1 running the latest firmware. Not sure if it can use firmware for the v2/v3/v4 models, though...

Lance · Jul 19, 2010, 21:26:19

Quote from: netgem21 on Jul 19, 2010, 20:07:07
Yep, it's the Netgear DG834v1 running the latest firmware. Not sure if it can use firmware for the v2/v3/v4 models, though...

That certainly is an old router. I would recommend getting another one even if only to hold as a spare if you rely on your internet.

netgem21 · Jul 19, 2010, 22:06:41

Quote from: Lance on Jul 19, 2010, 21:26:19
That certainly is an old router. I would recommend getting another one even if only to hold as a spare if you rely on your internet.

Yeah, I suppose

Anyway, I'm getting a loan router from a friend tomorrow, so I'll report back with the results. As I'll only have it for a short amount of time, what sort of tests should I perform? Finally, can anyone recommend a decent router if it turns out I need to replace mine? I'm looking for one with a clean/well designed control panel, gigabit ethernet and preferably not wireless, as I'm using a Time Capsule for that.

Once again, many thanks to all of you for your help with this!!!

Steve · Jul 19, 2010, 22:15:47

We need the router stats as soon as you connect to the test socket plus a BT speedtest if poss

netgem21 · Jul 19, 2010, 22:17:16

Quote from: Steve on Jul 19, 2010, 22:15:47
We need the router stats as soon as you connect to the test socket plus a BT speedtest if poss

No problem - thanks again!

netgem21 · Jul 20, 2010, 14:12:28

OK, second router just arrived. Testing it now. It's a Netgear DG834PN

netgem21 · Jul 20, 2010, 14:38:41

Here are the results. Doesn't seem that different to my DG834.

[attachment deleted by admin]

Steve · Jul 20, 2010, 14:51:35

I think you should contact support again since you've now tried a new filter and router,the slow speed is down to the profile but you've had a signifcant line degradation

Rik · Jul 20, 2010, 16:33:27

Though the d/s sync is some 20% better.

netgem21 · Jul 20, 2010, 16:50:23

So what are the next steps?

Rik · Jul 20, 2010, 16:55:22

Let support have the figures and BT result from the new router (they were at the test socket I take it?).

netgem21 · Jul 20, 2010, 16:57:40

Quote from: Rik on Jul 20, 2010, 16:55:22
Let support have the figures and BT result from the new router.

They have, but I'm just getting automated responses. They've recommended that I do not get an engineer callout, so I'm assuming they want me to live with 2mbps. I'm getting far better support on here, to be honest. Another option is killing the ADSL line and migrating the IDNet account to our other 'voice' line. I can't see any other options besides these.

EDIT: Yep, they're from the test socket.

Rik · Jul 20, 2010, 17:14:23

I don't think it's fair to call it an automated response. Your speed will rise, providing you remain in sync, to 4Mbps over the next 72 hours. To get back to your original 6.5Mbps may not be possible. IDNet can and will get an engineer out, but there's a very high likelihood that BT will raise a charge, which is why they are not recommending it. Some engineers are better than others, so you might or might not see an improvement as a result. If the engineer thinks the line has degraded, he will simply start the 10-day training over again, which will lower your fault threshold level, making it impossible to raise the speed as a fault in the future - iow, BT tend to move the goal posts in these cases.

Your choice is, essentially, have an engineer out, hope that he can do something, but be prepared to pay £160+ if he decides there's no fault, live with the speed once the profile has settled or move the service to your other line, with no guarantee that you will get the speed that the BT checker reports.

The only other diagnostic I can suggest is to use a battery-powered MW radio, de-tune it so you only have white noise, then follow the path of your phone wiring from entry point to router and see if the noise level increases anywhere. If it does, that's where the interference is.

netgem21 · Jul 20, 2010, 17:19:12

Quote from: Rik on Jul 20, 2010, 17:14:23
I don't think it's fair to call it an automated response. Your speed will rise, providing you remain in sync, to 4Mbps over the next 72 hours. To get back to your original 6.5Mbps may not be possible. IDNet can and will get an engineer out, but there's a very high likelihood that BT will raise a charge, which is why they are not recommending it. Some engineers are better than others, so you might or might not see an improvement as a result. If the engineer thinks the line has degraded, he will simply start the 10-day training over again, which will lower your fault threshold level, making it impossible to raise the speed as a fault in the future - iow, BT tend to move the goal posts in these cases.

Your choice is, essentially, have an engineer out, hope that he can do something, but be prepared to pay £160+ if he decides there's no fault, live with the speed once the profile has settled or move the service to your other line, with no guarantee that you will get the speed that the BT checker reports.

The only other diagnostic I can suggest is to use a battery-powered MW radio, de-tune it so you only have white noise, then follow the path of your phone wiring from entry point to router and see if the noise level increases anywhere. If it does, that's where the interference is.

Thank you for your response, but the responses I was receiving were not directly answering my queries. I just don't understand how this severe drop in speed can occur in such a short space of time with no apparent change in line quality, according to router statistics.

Rik · Jul 20, 2010, 17:23:43

One day I had a connection, the next day I didn't. Something in my internal wiring went out of tolerance and it stopped ADSL in its tracks. The problem is that we are using a Victorian infrastructure to do something it was never meant to. BT only guarantee a 28.8k data service. It's a hard truth but, while BT are essentially the monopoly carrier, they can do what they like, and ISPs can do little about it.

klipp · Jul 20, 2010, 18:34:08

I feel your pain netgem and fully understand your frustration.

netgem21 · Jul 20, 2010, 18:38:32

Quote from: klipp on Jul 20, 2010, 18:34:08
I feel your pain netgem and fully understand your frustration.

Thanks mate!

I think we're gonna get an engineer out, get his opinion, and probably kill the line.

All the support for this issue has come exclusively from this community right here, and I thank you all for your help.

I'll keep you updated!