Line still stable here at 4480 / 672 on ADSL1. No Interleaving. Excellent.

Question - do I still have to pay for the Increased Uplink speed with 21CN and ADSL1?

Apologies for the outbreak of morse code earlier please ignore it - it was a reply to Barry's signature which was in morse.

I don't think so, the DLM works differently on 21CN to 20CN. It will recognise that you've made a change (changed from ADSL1 to ADSL2+) and will pick that up in the back end systems. Now depending on what the DLM has already done to stabilise the line it could take between about a day and week or so before it makes any changes but it will learn. The easiest way to imagine, consider if you had a faulty modem at the point of activation causing a low sync rate or dropping connection and then swapped it after a week. The DLM in the first week may have applied interleaving and upped your target SNR a couple of times or even put you on one of the new special capped profiles but when it sees the new modem has caused the line to be more stable it will start to undo what it's done. It's cautious and won't change everything in one go, but it will go back to normal in a few days.

Your router might tell you, some do and some don't depends what sort it is. It's usually with the line stats.

At the moment the Member Centre interleave option isn't available on 21CN as the ordering process is entirely manual.

Thanks Dave. I'll keep an eye on it and report back in a week or so.

Probably something to add to the list of findings from the trial - ensuring that when the customer migrates to 21CN that they make sure they have their router setup correctly to make use of it! 

In general though, the migration was seamless (despite the above issue and the continuing dropping of downstream speed below that of ADSL1!). Certainly one of the reasons I have the Draytek is because of the years it was the only modem I could confidently leave and never have to worry about it failing to reconnect if the connection dropped. The daily/hourly(!) drops have been annoying, but for the most part only because I run SSH sessions and occasionally a VPN which of course break when the modem resyncs. The average user will probably not noticed or be disturbed by it.

No, that'll have been removed as part of the trial. Because it's a trial stage we've just set the download and upload speed to be the max each line can get and not made any limitations on what products can go on the trial or anything like that. At this stage with only a small number of people it's about getting different people with different routers and different lines and different usage patterns and see what happens. This may well change when we move beyond the trial, I couldn't say for sure but it makes sense to do it this way to try and get the as much information as we can early on.

Any one know why you see little or no increase in sync speed on adsl2 if your bettween  2-5mb on adsl1. Yet if your under 2mb you see an improvment in sync speed on adsl2.
i find it odd that it can improve really long lines but not  the 50+ db atten lines.
so whats the tech bit then that stops the average long lines improving yet improves really really long lines?

During the trial I have taken snapshots from the router and, having looked at these, there is nothing that really stands out about the day that the line did not disconnect.  During this stable period, when the line remained up for 44 hours, from the observations that I have made, the downstream SN Margin didn't drop below 6.5 dB, it remained between 6.5 db and 8.5 dB throughout.  At the relevant time on the day that the line did not disconnect, the downstream SN Margin was at 8 dB.  On other days, the downstream SN Margin was lower than this at the time the line disconnected. 

I have from time to time monitored the line using 'Router Stats', but I have done this mainly in the evening, as that is normally the time that the noise levels tend to fluctuate the most. I did however monitor the 'lunch time period' on the day of the switchover, the day after the switchover and, fortunately, on the 8th when the line did not disconnect.  I also monitored the lunchtime period yesterday and today to see if that would reveal anything.  I've attached a pdf file that contains edited 'highlights' which may or may not be useful in identifying the problem.

Apart from the regular 24 hour disconnections, my experience of the ADSL2+ trial has generally been good.  It was not so good when I lost Internet connectivity for 24 hours last weekend but  hopefully, interleaving will reduce the chance of that happening again.  Download speeds have increased and upload speeds have been equal to, if not better than on ADSL1.  The speeds are still being adjusted and have been reducing since I had the loss of Internet connectivity last weekend, so it will be interesting to see how things end up.  Unfortunately, my IP profile according to the BT speed tester has now gone down to 10,000 kbps.  It is still at 11,000 kbps in the Member Centre.

Good news - no disconnect today! 

I rebooted the router this morning just in case it was necessary as a result of the interleaving change.   I have no way of knowing that interleaving is now on the line, but I assume it to be the case.  Download speeds have been lower today at about 7700 kbps but the download sync speed is 11,847 kbps.  I haven't been able to get any readings from the BT speed tester so I am assuming that my IP Profile is still 10,000 kbps.  I'll report speed readings in a few days when the line has had chance to settle down.

I am syncing at 4416 on ADSL1 non interleaved,  and according to PN my line speed is 3500. However I seem to be clamped to only 3000 download? Last week I was getting 3268 downloads at similar sync speeds. I was also getting better upload sync speed at that time. Currently Upload is syncing at 672.

Edit: Now appears to be faster no longer clamped at 3000. 

(JELV also quoted this text on 20/11/2008)

What happens to the upload speed/sync rate at the end of the trial?

Will it be limited to 448kb/s?

   EDIT: Oops!  I see that my question has already been answered in item/answer #68.   

I'm getting only slightly better speeds as the old ADSL 8Mbps
It is also less stable than ADSL 8Mbps - and I've been moved from a 6dB to 9dB noise margin.

If a reduced upload rate allowed a slight increase in download speeds, then I'd definitely go for it (given the choice).
The ADSL2+ does bounce back from disconnections etc much more quickly than ADSL 8Mbits.

I was just wondering...any news in regard to the 31-12-2008 21CN orders

Dave T said he expected the orders to be submitted early next week. I expect these will complete the week after.

OK...Thanks

Actually, I'm getting such an excellent upload rate (1100Kbps+) that I would be quite happy for it to be limited to a smaller number
if that speed could be re-allocated to my download side.

Yep, they are being staggered over the course of the week as there's about 20 altogether to go through, should start completing next week. There's a ticket on each account which will get updated when the order is placed.