Description: This attribute specifies duration of the service lifetime supervisory timer which applies to non call-associated sessions providing bearer-independent connection-oriented transport for supplementary services. The timer limits the duration of a virtual call. It is started at the ingress Passport at the moment the first response message from the destination PBX has been received and stopped when the non call-associated session is released. If the timer expires, the non call-associated session is cleared. This timer is equivalent to the T-CCBS6 timer described in the relevant supplementary service specifications. A change of the timer value does not apply to timers already running.