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BT profile retraining... help

pepsi_max2k
Grafter
Posts: 108
Registered: 01-08-2007

BT profile retraining... help

Hi, I raised a ticket a week ago asking for a simple profile retraining from BT (who also had applied a 2 mbps cap months ago after faulty modem / a million resyncs, and never lifted it).

To cut a long story short, about 15 replies later I've finally been told:

Quote

Loop Loss 40.5
SNR Margin 17
ErroredSeconds 17
HecErrors 10
CellCount 0
Speed 2272

...They show that the SNR margin is 17, which is indeed well above the standard threshold, meaning the line is in theory capable of more. The error counters show that there are still errors occurring that this level though.

If you speeds were to increase, this figure would increase by a huge margin, resulting in higher volumes of data loss, an increase in disconnections and throughput problems, meaning any synchronisation speed gain would be negated.

We can if you wish raise this to BT to investigate, however at this time, we do not to advise and receive your acceptance of the following.

Should an engineer be dispatched and find that the source of this is located within your property, be this hardware or internal cabling, a charge of £54.05 may be levied. With this in mind, provided you are confident this is not as a result of local equipment, we will raise this for you, as the risk of a charge would be minimal...



Stats wise, when that test was done I was showing a local snr of 19, so it's not far off. Having plugged in to the master socket i now have:

Local Line Atten.: 40.0 dB
Remote Line Atten.: 23.5 dB
Local SNR Margin: 21.5 dB
Remote SNR Margin: 26.0 dB

Which from what i've just read ranges from very good to excellent. Cool

I'm not sure what they mean about the errors, but basically I've not experienced any disconnections over the past couple of days. Prior to that I spent a week with horrible sync problems caused by a faulty microfilter, and informed them of such, though I don't know if someone thinks they were caused by sync speeds instead, and that's why they think i may get more errors if sync increased. Before that I experienced barely any disconnections (ip seemed to change every few days, i dunno if that's normal or not, but i only noticed that due to having a router connected 24/7 ...).

As for BT, why would they send out an engineer just because I went through retraining and ended up with the same as I have now? Frankly, all I want is a chance at higher speeds which, from what i understand, means 1. BT need to lift the 2 Mbps cap they stuck on in august and 2. I need to go through retraining. Both of which I can't do myself, so unfortunately have to include PlusNet. If I end up with a 2000 kbps profile after retraining, so be it, at least I know it's not due to an artificial cap.

Anyone see a good reason for not replying along the lines "raise it with bt, lose the damn cap, retrain already"? Tongue

PS. happy christmas to all. Cheesy

EDIT: thought this might be of help, just found it in my ticket archive...

Quote
ID: 19959077 Tuesday 1st August 2006

We are contacting you regarding your broadband service, as your line has been identified as retraining syncronisation several times over a 24 hours period.

In the case of your account, it has been identified that your line has reconnected 4192 times on the telephone line xxxxxxxxx.

In order to try and rectify a problem with your service, the following checks should be performed in your own premises, to help confirm that your own equipment is not the source of this.

In addition to identifying your line as problematic, BT will be pro-activly applying a capped profile to your line, which will help in identification of problems on the line itself.


^ AFAIK, that cap was never lifted...
4 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

BT profile retraining... help

Hi,

Looking at the line test results in the ticket there's a number of errored seconds showing up. If these are just from a one off problem then decreasing the target SNR should be fine, but if they continue to increase then you could just end up with an unstable connection.

My suggestion would be to give it a week or so and as long as it remains stable send the ticket back to get the SNR dropped and we can retest it and see if there have been any more errors showing.
pepsi_max2k
Grafter
Posts: 108
Registered: 01-08-2007

BT profile retraining... help

left through christmas while i was away. just come back and it's still the same ip as on the 24th. no disconnections, no loss of sync. downloading / pings are as good as ever. haven't noticed any problems web browsing. my kit's fine unless there's a problem with telephone wire between master / wherever. and even so, it's clearly ok at 2000 k, now could someone just get me through re-training to see if it'll handle anything more? pretty please?
pepsi_max2k
Grafter
Posts: 108
Registered: 01-08-2007

BT profile retraining... help

Could someone please explain the possible meanings of the below as I've no idea whether it's a normal situation or not. Basically, in August 2006, a modem broke, resync'd lots, and this happened:

Quote
...it has been identified that your line has reconnected 4192 times...

In addition to identifying your line as problematic, BT will be pro-activly applying a capped profile to your line, which will help in identification of problems on the line itself.


Previous to this I had seen sync levels around 4 Mbps at times. After this, it never happened again, even though the fault was fixed by myself within a few days.

The following are various replies from PN staff over the last month after I became suspicious as to why I was still only getting a 2 Mbps connection even though I live just down the road from the exchange, have good SNR and attenuation levels and seemed to have better speed before an apparent cap was applied to the profile:

Quote
You're definately on Max, although there is a note on your account that they've set the speed to 2Mbps because of an intermittant problem from August.


Quote
BT's main ordering system believes that you are on Max, and the other is reporting that you are not, as proved by the levels of sync that you are currently attaining.


Quote
Your line was originally throttled by BT due to it dropping the connection quite a lot, and this still seems to be the case.


This one's a copy and paste from a BT document, which is what the above makes me believe has happened to my line:

Quote
BT Datastream Max/Max Premium products may under certain circumstances (as outlined in the Datastream Customer Handbook) be placed onto capped rate profiles to assist in stabilising the line or to ensure line rate is not less than the original line rate when re-grading over from one BT Datastream Office products. The capped rate profiles (500, 1000 & 2000) are equivalent to the Office products as per Table 4.


Also note table 4's Office 2000 product contains identical Up and Downstream rates as to those I'm achieving, and also BT's speedtester lists my IP profile as 2000.



Now, is the above just implying that my sync speed was automatically reduced to a 2 Mbps profile in August, and due to the current regular line conditions the normal auto monitoring all MaxDSL lines are put through, my line has never been seen to be capable of more than 2 Mbps and has just stayed like that due to the same reasons anyone elses would (even though before hand it strangely seemed capable of more).

Or, is there, as the above seems to suggest, some kind of artificial cap on the line over whatever automatic systems are in place, meaning that regardless of line conditions or automatic monitoring, I would never sync higher than 2 Mbps. If this is the case, can someone please tell the guys in ticket 20927629 to stop telling me to make sure my modem hasn't blown up and that my line will re-sync to whatever it's capable of if it's not going to without a little extra help.

Otherwise I'll quite happily close the ticket in the knowledge that I really am getting the sync speed that my line is truly capable of. Though had someone just said this at the beginning I could have closed it weeks ago :roll: .
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: 04-04-2007

BT profile retraining... help

Hi,

Essentially what BT have done is set a maximum sync speed on your line of 2Mbps due to the problem with the modem and the line resync'ing 4000 times

This isn't something that is done very often (4000 resyncs is the sort of extreme case where they would). If the line's stable now then I think BT should be able to remove the 2Mbps limit. I've pass the ticket back to the faults guys to see what we can do.