BLF between T26 and T22

[proof]

I have followed what seem to be very simple instructions for enabling BLF between a T26 and a T22 connected to an Asterisk box but I am not having any success.

Does anyone know if the two models are not compatible with communicating BLF?

If so, can someone provide me with a detailed walk through on how to get this to work?

Some specs:

T26 Firmware Version: 6.72.0.30
T22 Firmware Version: 7.72.0.30

Any help is much appreciated.

Thanks!