Reference ETSI TS 24 301 section 9.9.3.7.
----8----|----7----|----6----|----5----|----4----|----3----|----2----|----1---- | | Detach type | Switch | Type of IEI | Off | Detach | | ----8----|----7----|----6----|----5----|----4----|----3----|----2----|----1---- Type of detach (octet 1) In UE to network direction: Bits 3-2-1 0 0 1 EPS detach 0 1 0 IMSI detach 0 1 1 combined EPS/IMSI detach 1 1 0 reserved 1 1 1 reserved All other values are interpreted as "combined EPS/IMSI detach" in this version of the protocol. In the network to UE direction: Bits 3-2-1 0 0 1 re-attach required 0 1 0 re-attach not required 0 1 1 IMSI detach 1 1 0 reserved 1 1 1 reserved All other values are interpreted as "re-attach not required" in this version of the protocol. Switch off (octet 1) In the UE to network direction: Bit 4 0 normal detach 1 switch off In the network to UE direction bit 4 is a spare. The network shall set this bit to zero.