TAOS 9.0.x has a DIR called CALL-SWITCHING.
which is described as:
Attributes for pass-through and net-to-net switching

I'm having trouble finding any documentation for this command.

All that's listed in the profile is this
admin> read CALL-S
CALL-SWITCHING read
admin> list
[in CALL-SWITCHING]
enabled = no
comparison-rule = { no }
admin>

Can anyone shed some light on this feature?

Mark