Preemption, circuit reserved for reuse/ Prefix 1 dialed in error (NI-2: National ISDN 2)
Cause
Cause value 09 indicates that for Autovon switching networks, a call with a higher priority blocks the call attempt in order to reserve the requested channel for reuse.
Cause value 09 (NI-2) indicates that the remote user need not include the prefix 1 as part of the digit string in the CALLED PARTY NUMBER.
