I have a feeling I already know what the answer will be, but here we go.
I have recently switched from a paid PBX using A500 Sangoma cards, to Freepbx using two B400 cards. The sangoma cards provided a Y-Cable so that two ISDN lines could be plugged into a single port giving 4 B Channels. See here :
Specifically the product A108 T1/E1 “Portsplitter” Cable.
When plugging the same cable into the B400 I get two B channels and no ability to increase the channels via the FreePBX interface. My question is whether these cables can be used with the B400 cards.