附着流程再明确

1 [RRC] UL RRC Connection Request

2 [RRC] DL RRC Connection setup

3 [RRC] UL RRC Connection Setup Complete 携带了[NAS]Attach request

4 [NAS]Attach request携带了[S1AP]Initial UE message

5 MME收到Attach request以后，给SGW发Create Session request消息，同时携带[S1AP]Initial UE message

6 SGW收到Create Session request消息以后，加上SGW TEID,继续将该消息发送给PGW，同时携带[S1AP]Initial UE message

7 PGW生成自己得TEID然后发Create Session Response给SGW,SGW再回传给MME,这里面带上了SGW得TEID和PGW TEID

8 MME收到Create Session Response以后，发送[NAS]Attach Accept给enodeB

9 [NAS]Attach Accept 携带了[RRC]RRC Connection Reconfiguration并且携带了Initial Context Request消息

10 [RRC] RRC Connection Reconfiguration Complete