S1-MME接口消息标识

低吊的寂寞

流程编码	流程类型	标识比特位    （从低位比特开始）	消息类型
1	Attach	0	NAS: ATTACH REQUEST
		1	NAS: ATTACH ACCEPT
		2	NAS: ATTACH COMPLETE
		3	NAS: ATTACH REJECT
5	TAU	0	NAS: TRACKING AREA UPDATE REQUEST
		1	NAS: TRACKING AREA UPDATE ACCEPT
		2	NAS: TRACKING AREA UPDATE COMPLETE
		3	NAS: TRACKING AREA UPDATE REJECT
15	S1 handover in	0	S1AP: HANDOVER REQUEST
		1	S1AP: HANDOVER REQUEST ACK
		2	S1AP: HANDOVER FAILURE
		3	S1AP: HANDOVER NOTIFY
20	UE context release	0	S1AP: UE CONTEXT RELEASE REQUEST
		1	S1AP: UE CONTEXT RELEASE COMMAND
		2	S1AP: UE CONTEXT RELEASE COMPLETE
30	Authentication	0	NAS: AUTHENTICATION REQUEST
		1	NAS: AUTHENTICATION RESPONSE
		2	NAS: AUTHENTICATION FAILURE
		3	NAS: AUTHENTICATION REJECT