The ISUP cause codes are based on the earlier ISDN standards.
Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN User Part. Look at the following ISDN specifications: Q.931 and Q.850.
This cause value is used when a mobile station has logged off, radio contact is not obtained with a
mobile station or if a personal telecommunication user is temporarily not addressable at any usernetwork