Be very careful changing to Adsl2+ on long lines.

[kinmel]

I suggest people using the 2700 to improve long phone lines think very carefully before changing over to Adsl2+, I have had a 40% drop in performance.

Using a 2700HGV my phone line supported a 4 meg connection with very little variation over the last few years.

I knew that some long phone lines could  work less well on Adsl2+, but thought that after the 10 day  training period Idnet would be able to ensure that the line would sync at the usual 6dB and I may have to take a drop in sync rate.

Apparently that is not what happens on long lines, during the training period the line is put into a profile band and Idnet is unable to alter that.

My AdslMax 4 meg line has been profiled for Adsl2+ as a 1 to 3 meg connection and is sync'd at a fixed 3059 even though the SNR is above 10 dB.  The BTspeed test is now 2310Kbps.

So I would be be grateful for any advice on how to move forward.

If I change back to an AdslMax connection, will there be an improvement. ?

Are new phone lines on WBC enabled exchanges connected to a DSLAM, or to a MSAN ?

Do LLU providers apply the same profiling, or equivalent, as BT for AdslMax and Adsl2+ ?

[Simon]

What is classed as a 'long' line?  Thankfully, I am still on Max, but I'm sure the day will come when I am forced to switch.  I'm about 1.5 miles from my exchange.

[Rik]

Hi Alan

The vast majority of us moving to WBC have had positive experiences, but for some lines it just hasn't worked out - possibly due to line characteristics, possibly the MSAN/Router combination. Not all lines are banded, either. AFAIK, banding is only triggered when a line can't be stabilised by normal DLM techniques, ie it's an extra layer over and above Max DLN. My 57db line is not banded and has gained me 1.5M over the Max equivalent, though admittedly, the last 500k was gained by the trial of a facility to allow ISPs to override DLM.

I understood that IDNet could, in some circumstances, request that banding be removed. I'll check that.

TBH, I don't think anyone knows what will happen if you re-modulate to ADSL Max, few if any people have tried it. Again, afaik, new lines would automatically go onto MSANs at enabled exchanges.

LLU providers don't, to my knowledge, use profiling in the same way - it's been their big advantage over BT products.

[Rik]

What is classed as a 'long' line?  Thankfully, I am still on Max, but I'm sure the day will come when I am forced to switch.  I'm about 1.5 miles from my exchange.

No simple answer to that, Simon. Attenuation greater than about 50db, but it very much down to line characteristics as well. Listening to John Henry, btw. 

[Simon]

Attenuation 34.7 dB, but I don't want to hijack Alan's thread.

Enjoy JH! 

[Rik]

Hi Alan

I've done a little digging. Your banding is as a result of the line attenuation, 63db, and the error count. IDNet have asked BT to move you up a profile band but BT have refused citing the error count. A new line can, for the moment, still be provisioned with Max via a DSLAM, but there's no knowing when BT will move people to MSANs as they decommission the 20CN network. It's impossible to get your line physically moved back to a DSLAM except via a cease and re-provide which would leave you without broadband for several days and incur a new connection charge of £47.

[Rik]

Attenuation 34.7 dB, but I don't want to hijack Alan's thread.

Enjoy JH! 

Not long, I am.

[kinmel]

Hi Alan

I've done a little digging. Your banding is as a result of the line attenuation, 63db, and the error count. IDNet have asked BT to move you up a profile band but BT have refused citing the error count. A new line can, for the moment, still be provisioned with Max via a DSLAM, but there's no knowing when BT will move people to MSANs as they decommission the 20CN network. It's impossible to get your line physically moved back to a DSLAM except via a cease and re-provide which would leave you without broadband for several days and incur a new connection charge of £47.

Thanks Rik

I have asked for the line to be changed back to AdslMax and I will see how that performs on the MSAN before making a final decision about LLU..

[Rik]

 

[kinmel]

Like every other experience, this one is going to cost me money.

Never mind, it all comes out of the kid's eventual inheritance

[Rik]

And deprives the Government of some tax.

[kinmel]

Overnight I have been changed backed to AdslMax, although still connected at the exchange to Adsl2+ equipment (MSAN).

After a re-boot this morning I am sync'd at 4640  @ 6dB, which is about the same as the line achieved on AdslMax through the DSLAM.

The attenuation has dropped from 63.1 on Adsl2+ to 57.1 on AdslMax.

My current profile is 3500 and BTSpeedtest gave a D/L of 3717Kbps

I don't know if I am on a new 10 day training period, but I may have got away with it 

[Lance]

  indeed!

[Steve]

 

[Rik]

That's good news, Alan. It looks like your line didn't like the higher frequencies of ADSL2+.