The logical table is an abstraction of the entity that uses a time slot.
For an example, a VT1.5 time slot can be used as a DS1 and this DS1
entity is refered to as a logical port.
Rows in this table are created automatically when a trunk is activated
for this OSAP. The information in this table is local to this OSAP and
not shared. Before the trunk was activated, it was configured with
a list of logical port index(es). A logical port index maps directly
to a timeslot index from the shared timeslot table. A row in the Lport
table will be created for each logical port / timeslot that is defined
in the lport list for a trunk that is used/dropped by this OSAP.