I’m guessing that the quiet line test will be of no use to someone on FTTC and DV ( be interesting if someone on these products dialled 17070 , presumably there isn’t the option for QLT ) , but customers should still be able to test their own line by logging into ‘My BT’ ( or whatever it’s called ) and using the line test function, the option to call customer service and speak to an advisor is also available , getting them to test the line.
Presumably , ‘test access’ is still via the PSTN exchange equipment ( so would in effect test both the E side and D side cables , although the E side and exchange equipment are effectively redundant ) unless some recent upgrades have now shifted the line test facility to the FTTC equipment from the ‘exchange’ , any defect found should be reported to Openreach by the CP ( BT in this case ) to be rectified.
It may well be the OP has a line fault , being on DV removes one element of the customer being able to diagnose the issue, they probably cannot truthfully report the issue as a ‘noisy line’ anymore , but can still report slow broadband .
