A.2 Introduction
24.3803GPPMission Critical Push To Talk (MCPTT) media plane controlProtocol specificationRelease 18TS
A.2.1 General
The signalling flows provided in this annex follow the methodology developed in this specification.
A.2.2 Key required to interpret signalling flows
In order to differentiate between messages for floor control, pre-established call session control, MBMS subchannel control messages, SIP messages and RTP media packets, the notation in figure A.2.2-1 is used.
Figure A.2.2-1: Signalling flow notation