Can I upgrade to ADSL2+

[#1]

Hi Adam,
just got home and checked my router details. Looks like the upload speed cap has changed as I now see 888kbps rather than 440Kbps before. However this is a little lower than expected and as suggested by the BT wholesale site:
Our test also indicates that your line could support an estimated ADSL 2+ Annex-M broadband upstream line speed of 1.5Mbps and downstream line speed of 17Mbps;
Is it fully uncapped or has the cap just been raised a little? Maybe this will change over the 'bedding in' period and I'm fussing for no reason 🙂
My download speed is excellent and I'm very happy with that thanks.
Thanks
-Mat

[#2]

Annex-M is a higher upload speed option available only on business packages, I believe (and at extra cost!) so you won't get anywhere near that unless that is in fact the package you currently have.

[#3]

Also, whereas uncapping only makes a marginal (if any) change to the downstream, Annex M shifts frequencies used for downstream to the upstream so there will be a drop in the downstream speed equal to the increase in the upstream.
If it were available on residential the extra cost would be around £10.

[#4]

Fair enough. Thanks for clearing that up for me. So it isn't actually uncapped
then. Just capped at a higher rate.
Thanks
-Mat

[#5]

No it is uncapped. The maximum upstream sync speed on Annex A is a little over 1Mbps, the actual speed depending on line conditions and interleaving ststus. Almost certainly it will be upstream interleaving being 'on' that is causing the restriction to 888kbps on your line (in the same way that downstream on ADSLmax on some routers is restricted to 7616kbps).
David

[#6]

I don't know enough about interleaving but have heard that you can turn it off. What advantages would I get from requesting this? How about disadvantages then?
Thanks
-Mat

[#7]

Interleaving is aimed at combating short bursts of noise on the line, but the process increases latency. Kitz's Interleaving Explained page is a good reference.
Interleaving is normally set to auto so the DLM can control its parameters.
David

[#8]

Thanks David,
I'm led to believe that an increase in latency is only really bad for gamers so that doesn't bother me too much. However, if I can eke out some more speed then I'll do what's needed 🙂
Possibly a stupid question, but how can I tell if turning off interleaving is good for me? Is it 'suck it and see'?
Thanks
-Mat

[#9]

I think it is more a matter of "wait and see."
As Spraxyt advised interleaving should be set to Auto by default - having read the Kitz link and out of interest perhaps this one as well you could then try to find the relevant connection stats on your router - if interleave depth is 1 and RS correctable errors is zero then interleaving is currently off.
My understanding is that if it is currently on, it is probably on for a reason (at least as far as the DLM is concerned) but could potentially change over the course of time, which could be weeks rather than days.

[#10]

OK-dokey. I'll leave alone and see what happens for now then.
Thanks to everyone for your help and thanks to PN for the pretty smooth upgrade
Cheers
-Mat

[#11]

Hi mlavende,
I think that'd be the best bet, see what it settles at after the training period and then we can look at squeezing the best possible speed out of the line. Glad the upgrade went so smoothly, thanks for the feedback

[#12]

Interesting that this mail arrived today:
Dear Mr Matthew Lavender

We have good news for you. The exchange equipment we use to provide your service has now been upgraded, and we can offer you a faster 'upto 20Mb' service.
You don't need to do anything, and we'll switch you over automatically, for free.
We expect this to happen within the next 5 weeks.
There may be a brief drop in connection for about 5 minutes on the day of the change, and you may see varying speeds for the first few days after we've upgraded you. This is expected, and is nothing to worry about.
Please note: you may receive messages advising on the progress of your order over the next 5 weeks. If you receive a message notifying you that the order has failed, don't worry - you don't need to contact us and your service will continue as normal.
We've created an FAQ for the upgrade here:
http://community.plus.net/faster-plusnet-broadband-for-free-faq/
If you have any further questions please raise a ticket by going to http://help.plus.net
Kind Regards,


I'd love to think that I was responsible for kicking off the upgrade of all the Markyate connections. Should get me a fortune in referals 🙂
Cheers
-Mat

[#13]

Hi there,
Not sure why that's been sent given that your upgrade has already completed, I've closed the ticket for you though. I suspect it's just that the automatic upgrade was scheduled before we'd placed the manual order, though I can assure you there's nothing to worry about and things won't change at all.