Have a broadband slowwwwwwwwwwwww problem On bt test site results are

dsl connection
8128kbps down load
448kbps upload
Ip profile is 135kbps
actual 115kbps

All i need to know in english is what is going on as everyone Isp and BT will not take responsability or is it at my end, have problems with slow speed on any pc i try I am pluged direct into enginners socket at bt incoming socket
This is the second time since christmas it has just droped off with no other problems for 6yrs plus, sometimes have to unplug router (d linkg604t) as i cannot conneect once powered up connects again without a problem and at full speed so cannot see a fault there