Using an ADSL filter when an old corded phone doesn’t ring is a know ‘fix’ for non ringing , but it’s a ‘worth a try’ option for flaky CLI , certainly not worth the expense of buying one to try , it’s more of an option to try if you already had one or more in a drawer from previous broadband setups .
As far as CLI working 50% of the time (or thereabouts) there was a thread on here a while back , pretty much the same symptoms , except they didn’t mention the DV adapter was in use between the hub and the handset until pretty late in the thread , basically their equipment worked fine connected directly to the hub , but the phone only displayed the correct CLI info every other call when connected via a DV adapter , this sounds very similar if not identical to your experience.
As stated on that thread , I’m unaware of any other provider other than BT that provides any similar ‘adapter’ kit for free when they move customers onto their equivalent of DV , their customers are told to plug their own existing phone directly into the router socket , that’s it …..by supplying DV adapters and before that DV handsets , BT gain no plaudits for providing them , but plenty of complaints if they don’t work perfectly, BT were under no obligation to supply anything , every other supplier decided not to bother .
Its pretty clear the DV adapters supplied for free are not perfect in forwarding the CLI information , from the hub to the handset, but in my opinion the solution is either you throw them in the recycling if their performance is unacceptable, even if you need to do some rearranging of your existing equipment and sockets to allow your own phone equipment to connect to the hub directly ( as you would if you were a customer of Sky , Vodafone etc ) or you put up with their failings .
