10.25.2.10. Terminal Portability 
Terminal Portability allows short-time parking of a call. By entering
a two digit identification number the call is parked in the node. As
long as the call is not resumed, the terminal can be exchanged or disconnected.
It is also possible to resume the call from a different terminal linked
to the bus by entering the identification number.
A call can only be parked for a maximum of two minutes.
- configuration: In COS, the parameter TP must be activated for the voice service and bit 6 in byte 3 of the assigned option table must be set.
- restriction: if the station is member of a call pick-up group, the call cannot be parked in the PU. It is, however, possible to transfer a parked call from the PU.