Moving from 8Mb to 20Mb product - odd line speed estimates

I'm currently on Premier Option 1 (up to 8Mb) and my line speed is around 6.6Mbps.

I'm interested in changing to Extra or Pro, both of which offer 'up to 20Mb', however PlusNet's estimated speed for these products is only 2MB when I input my phone number and postcode.

Is this a mistake ?

My exchange is ADSL2+ enabled, yet BT's own speed estimate is also only 2Mb and they imply I can't have one of their <20Mb products.

What are the factors that will determine my new line speed if I change ?

I currently have a very stable 6Mb connection. Rembering the speed problems some people faced going from 2Mb to MaxDSL products years back, is there any chance I could end up worse off moving from MaxDSL to ADSL2+ ?

My router stats are :

ADSL Link Downstream Upstream
Connection Speed 8128 kbps 448 kbps
Line Attenuation 27 db 7 db
Noise Margin 8 db 26 db

Any input would be appreciated.

The speed estimates are usually between very conservative and completely wrong and can only be considered as a guide. BT says I can only get 500Kbs max (on ADSL & ADSL2+) but I'm currently syncing at 2Mbs and sometimes even 3Mbs.

FYI Extra is more heavily traffic managed than your current product so I would recommend paying a little more and go for PRO - on a market 3 exchange you will pay 16.99 for 20GB peak (and much less to zero traffic management) although speeds are not always as fast as would be expected (I'm on PRO).

So given your stats I would expect syncing at around 9->10Mbs with speeds approaching 8Mbs throughput. Your line attenuation suggests your line length is not too bad. You may benefit with having interleaving on but you can have it turned off if you are into gaming. Note sync speeds above 8128 need ADSL2+.

Most lines are being automatically put on 21CN network (which can give 20Mbs) when you change products to one that supports 20Mbs speeds. You can then see how it works using ADSL1 and then request a change to ADSL2+ via a ticket. If you find ADSL2+ is worse you can be put back on ADSL1 (or you can force this on some routers). One other benefit is a much higher upload speed as you can ask for the 432Kbs upload restriction to be lifted.

I would certainly give it a go. If you do find you get worse speeds then PN will put you back on ADSL1.

Edited by deleted (Thu 15-Apr-10 23:41:57)

I reckon an ADSL2+ connection speed of well over 15Mbps, possibly even just over 17Mbps. IP Profiles corresponding from 13,000 to 15,000kbps.

The Plusnet figure is copied straight from a BT database, possibly the same one as there are two or three that can vary, so it isn't surprising the figures are the same. My figures are based on the results from the ADSL2+ estimator, (usually accurate wrt connection, a bit dodgy wrt throughput), and the ADSLn speed v attenuation graph both of which you will find on the Useful Links page of my website. There is also an IP Profile page.

Note that your attenuation on ADSL2+ will be about 3dB higher than on ADSL. The estimator takes that into account, the graph does not.

Thanks for your comments Peter.

I am considering Pro as this will save me £5.50/month and give me unrestricted speeds, although Extra would almost halve my current bill for Premier !

I have been looking at the traffic management for Premier vs Extra and yes - Extra does look a bit more restricted.

I'm pretty sure I got a modest speed boost when I was moved over to 21CN on Premier, so I guess that's a good sign for moving from ADSL to ADSL2+ from what you've said ?

I'm not sure if my Netgear DG834G (v1) router supports ADSL2+, but I've got one of PlusNet's Thomson routers on standby in case I need it if I switch.

In reply to a post by RobertoS:

I reckon an ADSL2+ connection speed of well over 15Mbps, possibly even just over 17Mbps. IP Profiles corresponding from 13,000 to 15,000kbps.

Wow - really ? That would definitely be a worthwhile increase

I'm pretty sure I got a modest speed boost when I was moved over to 21CN on Premier, so I guess that's a good sign for moving from ADSL to ADSL2+ from what you've said ?

That's a bit worrying and ties in with what Peter estimates, not what I did. ADSL2+ = 21CN on BT Wholesale based connections.

As I believe the WBC/WBMC system is still highly suspect, perhaps you should take his figures, not mine which are what you would get on a non BT Wholesale one (LLU).