Question about 21C

[#1]

I've been having a few speed problems and still have an open ticket number 65069366 although the main problem has been fixed I did ask the following question which was not answered. perhaps somebody can give me a simple answer
I recieved a message that my line was transferred to 21C on the 25th Jan, what doe's that mean, could I expect an improvement to my line speed.
Many thanks in advance

[#2]

Hi there,
That basically means you've been upgraded to BT's 21 century broadband network, for yourself that should mean an estimated maximum download speed of around 5mb.