IP profile / stable rate

Just tried the new BT Speedtest.....

http://test.speedtester.bt.com:50301/

(For the record, I didn't change any login details)
And got the following results

IP profile for your line is - 5500 kbps
DSL connection rate: 448 kbps(UP-STREAM) 6176 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 5165 kbps

Portal page says my stable rate is 8000 kbps so is their a difference between stable rate and IP profile?

Cheers

Test1 comprises of Best Effort Test:
IP profile for your line is - 5000 kbps
DSL connection rate: 448 kbps(UP-STREAM) 5696 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 2543 kbps

//edit: Plusnet state my stable rate is 6000 (it had been at 5500 for the last week).
Your current broadband speed is 6000 Kbps

test2

IP profile for your line is - 5000 kbps
DSL connection rate: 448 kbps(UP-STREAM) 5696 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 4495 kbps

Edited by deleted (Tue 19-Sep-06 18:11:02)

Just tested my works business account where I can actaully see the exchange from the window :P

IP profile for your line is - 7150 kbps
DSL connection rate: 832 kbps(UP-STREAM) 8128 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 3216 kbps