[Asterisk-Users] Debugging zaphfc + PBX integration

[Frank Sautter]

Gavin Hamill wrote:
> I know the cables themselves are wired correctly because our local PBX support 
> made them, and they work perfectly when plugged into a real BT ISDN2e wallbox 

it seems as if this is exactly your problem.
the wallbox has a NT pinout => straight trough cable
the hfc card has a TE pinout => you need a cross-over (isdn not 
ethernet!!) cable to connect to your local pbx which also has a TE 
pinout. the nt/te switches on the hfc card do not cross over the rx/tx 
pairs of the card. this has to be done with the cabling.
i don't think you will need any termination resistors if your cable is 
only a few meters and does not have any other devices on the bus.

regards
  frank sautter