Free 20mb Upgrade swizz ?

[#1]

We were recently emailed to say that we would be moved to a new 20mb (max) ASDL2 upgrade for free on July 25th. The email also stated that tests on our line suggested that it was unlikely that our speed would increase after the upgrade. True enough, our speed prior to July 25th of an average 6.8mb/s has now dropped to an average of 6.1mb/s
However, tonight i accidentally noticed that the upload speed had improved from an average of 30kb/s to an average of 1mb/s !!!!
So, can someone explain to me in plain English i can understand please, why my upload can more than treble in speed yet my download speed can drop ?
Many thanks in advance.

[#2]

Just the way it works, on 21CN if your upload is uncapped then it can take some speed off your download.  Used to be you requested to uncap your upload removed due to this, but seems its the default now.

[#3]

That's part of the reason. If the OP had looked at his router stats before the upgrade I det they had a high noise margin for upload which meant it could have gone faster if the technology allowed.

[#4]

Hi Welshy
As your transfer to 21CN is recent, your line is still training (10 days) and may resynch a couple of times until the equipment settles down to your optimum speed.
For upload speed, 21CN provides 1.4 mbps max, depending on line conditions, again this may change until line training is complete.
If you can post your router stats, someone may be able to give a clearer picture on what you should expect to see regarding the download speed.
cheers
Graham

[#5]

Hi Graham, is this what you mean ?
Link Information

Uptime: 0 days, 17:23:22
DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1.235 / 7.744
Data Transferred (Sent/Received) [MB/MB]: 90,31 / 594,81
Output Power (Up/Down) [dBm]: 12,3 / 0,0
Line Attenuation (Up/Down) [dB]: 19,8 / 36,0
SN Margin (Up/Down) [dB]: 5,5 / 10,7
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): -
Error Seconds (Local/Remote): 386 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 10 / 1.290
HEC Errors (Up/Down): 7 / 2.312

[#6]

Hi Welshy,
Your line speeds are performing how they should be. Your upload is uncapped which can have a very small detrimental effect to your download speeds, but not anything that you would really notice. You can check your speed estimates at <a href="http://www.dslchecker.bt.com/adsl/adslchecker.welcome">the broadband availability checker</a>.

[#7]

Thanks everyone for explaining, thats all i needed to know