Your speed depends on the distance from the exchange to your phone port,
you can install a high speed box ie where you plug your phone in its a form of capacitor
im with bt but i use a high-speed Cisco router.
you can try this too it does work a little mate i do this every few mths to increase my bandwidth by at least 20%.
Ok here we go...
1.) log on as Administrator.
2.) start - run - type gpedit.msc
3.) expand "local computer policy"
4.) then expand "administrative templates"
5.) then expand "network branch"
6.) Highlight the "QoS Packet Scheduler"
7.) on right window double click "limit reservable bandwidth"
8.) on setting tab check the "enabled"
9.) change "Bandwidth limit %" to 0
You're done.It would be a good idea to reboot after this.