ExecIf

ExecIf($["${FROM_DID}"!= ""]?Set(direction=t)

ExecIf($["${FROM_DID}"= ""]?Set(direction=r)

Mixmonitor(,${direction}(/path/filname.wav))

DAHDI 3.0

DAHDI 3.0 will only compile on kernels 4.15 or newer.

"The setup_timer functions were removed in upstream kernel v4.15, and therefore
this change is needed in order to compile DAHDI for kernels >= 4.15."

Use DAHDI 2.11.1 for older kernel

https://issues.asterisk.org/jira/browse/DAHLIN-366