ADSL Standards - confused!

[#1]

Hi Kevin,
Yes you can have an SNR Target of 3db on ADSL (21CN)

[#2]

Ok Chris old fruit,
Shall we stop trying to dance the tango on this one please?  
In Summary, I can have a target SNRM of 3dB on my ADSL(1) over 21CN service and / or I could get the line switched to ADSL2... given your experience would you consider either of these to be wise on my residential line please?  You were instrumental in sweating a better synch speed out of my business line (ADSL2+) which had the same attenuation as this line albeit serviced by poorer infrastructure.
If the informed opinion is "no" then fine, if "may be" then can we give it a try please?  I'll let you lead!  
At the moment, I'm not convinced that I want to spend another £10 a month on fibre for speed I do not really need... I'd be quite happy with something nearer "up to 16Mbps" but to get that I'd need to move the house!  

...whilst I am sorting out my ADSL confusions... During the time I have been busy running a pub 7 days a week, I've missed the change in product positioning - I note that ADSL2 is now sold "up to 16Mbps" - I thought this technology (21CN / ADSL2+) delivered up to 24Mbps.  Is this a change to technology capability or is it a change in expectation setting?

Cheers,
Kevin

[#3]

OFCOM Rules - the up to is what 10% of the users get

[#4]

Jim,
Thank you - some catching up on my part required.
Is that 10% expectation what the WORSE 10% get (that is 90% get better than 16Mbps) or what the BEST 10% get (that is 90% get less than 16Mbps).
If the 90th percentile is 16Mbps, then precious few must be getting anything like 24Mbps! 
I take it though that if you are one of the very lucky few, if your home is next to the exchange, ADSL2 will still technically deliver a maximum of 24Mbps?

Thanks,
Kevin

[#5]

I am in the bottom 10%
It is the number which the best 10% get

[#6]

I know this breaks the rules, but I fear due to Jim and my sub-point dialogue, DCT might have missed reply 16...

[#7]

Quote

In Summary, I can have a target SNRM of 3dB on my ADSL(1) over 21CN service and / or I could get the line switched to ADSL2... given your experience would you consider either of these to be wise on my residential line please?  You were instrumental in sweating a better synch speed out of my business line (ADSL2+) which had the same attenuation as this line albeit serviced by poorer infrastructure.

Your line is pretty border line, by rule of thumb, I'd move people who have a Loop Loss of 45db and under, yours is 50db. your line currently has a few errors on it, not a mass amount but a few - I wouldn't disturb how your line is operating at present. We could try 3db on your line on ADSL1 but my best guess would be that it increases the amount of errors on your line 😕

[#8]

Chris,
Thank you for the rule of thumb on the boundary - will take good note of that.  The business line was though 50dB too.
Could we try 3dB please?  I guess that the worse that could happen is that if I get a higher level of errors and if I resynch at that time  I'll get a slightly lower synch at 3dB... Which then ought to be reasonably stable?
If it proves to be too bad, is it a pain to switch back? 
Thanks,
Kevin

[#9]

Hi Kevin,
Before I do it, just so that you're aware, the 3db profile could cause your connection to become intermittent and the high error rate (potentially) could cause a large number of sync drops.
As the change would be made via SNR Reset, you would need to wait for the 10 day training period to complete before we can reset the line again. If DLM does it's thing, it should move you to 6db automatically though.
If you're happy for me to go ahead, I'll get that changed for you.

[#10]

Chris,
From your description, it sounds like if it misbehaves, it will do so in a predictable manner.  You imply that if this is not viable, the worse that is likely to happen is that after a few disconnects, I'll be back at 6dB due to DLM doing its job - no worse off, no pain to PN to put right...
I can live with the risk of a few disconnects... please make the target 3dB.
Thank you,
Kevin

[#11]

I've had to manually request for this to be changed so it may take a little longer than the normal up to four hours.
Let us know how you get on with it.
EDIT - To add, the SNR reset has failed and we're not able to get you down to 3dB with the current product you're on.
We can arrange to move you to ADSL2+ which will then give us the option of 3dB is you wish?

[#12]

Chris,
An interesting development.  Why can the target not be moved in my circumstance?  Is there some anomaly with its configuration, such that the standard systems cannot manage it?
Is ADSL(1) over 21CN a dog's dinner which requires manual intervention for what are otherwise easy configuration changes?
I'm beginning to feel like a pain now, distracting you from fixing real issues... All I wanted was to try to squeeze a bit more out of my line, as was achieved on my 50dB business line - ADSL2+ 6Mbps (ish) at 6dB with capped US.  Chris Pettitt says 50dB is outside his (best advice) rule of thumb for ADSL 2, but if there is agreement between you that it is viable, please go for it.
Two separate subjects...
1. Is there merit in forcing a firmware upgrade please?  Nite the router I'm using is the ex business account as that seems to work much better with my wifi printer - do you need the serial number
2. Any chance of a response to my PM from last weekend please?  Yup I knows you are very busy...!
Thanks,
Kevin

[#13]

It's down to the ADSL product you're on, the lowest we're able to get is 6dB.
There's no harm in trying ADSL2+ as we can always change back if needed, I've placed the order to got you moved over but this won't complete until Tuesday 22nd April.
If you PM me your serial number I can get that remotely upgraded for you, I'll also make sure I get back to your PM before the end of the day.

[#14]

Chris,
Thanks, PM sent.
Looks like more learning on ADSL standards today...
t'other Chris thought (like me) that one could get 3dB on ADSL1 over 21CN
I thought (from what I've read on PN's site) that speed banding only applied to ADSL2 / ADSL2+ services... looking at a long on going issue elsewhere I'm concluding that it rather applies to 21CN services, irrespective of being ADSL(1) or ADSL2.

You lives, you learn, you become another day older!
Cheers,
Kevin

[#15]

Chris & Chris,
Thank you for your help on this.  ADSL 2 came on a little after 1am today.  There has been one re-synch since them, though a number of PPP session resets (one by me).

Quote

Link Information Uptime: 0 days, 1:11:48 DSL Type: ITU-T G.992.3 Bandwidth (Up/Down) [kbps/kbps]: 888 / 5.326 Data Transferred (Sent/Received) [MB/GB]: 304,93 / 1,96 Output Power (Up/Down) [dBm]: 12,8 / 0,0 Line Attenuation (Up/Down) [dB]: 28,6 / 50,0 SN Margin (Up/Down) [dB]: 9,1 / 3,0 System Vendor ID (Local/Remote): TMMB / ---- Chipset Vendor ID (Local/Remote): BDCM / IFTN Loss of Framing (Local/Remote): 27 / 0 Loss of Signal (Local/Remote): 3 / 0 Loss of Power (Local/Remote): 0 / 0 Loss of Link (Remote): - Error Seconds (Local/Remote): 1.710 / 0 FEC Errors (Up/Down): 500 / 3.740 CRC Errors (Up/Down): 1 / 15 HEC Errors (Up/Down): 0 / 174

Synch speed is up, but not quite as much as I had hoped for, SNRM is 3dB. It is hissing rain here, so there is a low level of discernible line nose, but not something I suspect can be found and remedied.
Looking at the BQM the line looks like it is delivering a much improved service.  All in all a good result I think, though I'll keep a watch ver the 10day training period.
Any thanks,
Kevin