[Asterisk-Users] TDM400P > BT

[Richard Alexander]

The PBX style has the capacitor to make the "bell" line but does not
have the test resistor or surge (lightning) protector.

Some RJ11 style modem leads are just straight US phone leads (middle two
pins connected and reversed between connectors) but some use different
pins on the connector at one end. Perhaps you have one of them.

What are you planning to connect to the TDM400P ultimately. Connect to
patch panel? Directly to cable runs, or to phones in same room?