I know from BT's own FAQ post (http://btbusiness.custhelp.com/app/a...inspiration%3F
) that they advise the systemphone is connected to an extension socket and not an extension lead. They advise the reason for this is because the featurephone is terminated in a 6 core cable/plug.
From my own experience I have found that POTs work when connected to the inspiration via an extension LEAD. Systemphones, however, just don't turn on at all. No display, no dialtone, nada.
What I don't understand is WHY! :-)
The featurephone needs 4 cores, two data, two voice. Fine.
A POT needs 2 cores, voice. Fine.
What does the extension SOCKET provide that the extension LEAD cannot, pray?