I’m trying to get T.38 passthrough working on Asterisk 188.8.131.52. It isn’t working. Calls go through and are answered, but the fax machines are unable to communicate. I checked the value of CHANNEL(t38passthrough) and it seems to always be 0. One side is Level 3 T.38 TN and the other side is an Adtran NetVanta with POTS ports. What would cause Asterisk to not offer t38 passthrough on a channel?