Hello, Is there a state diagram available which shows the state transitioning for all Channel Events and Channel States? Also, I've wrote a simple ESL application which listens for all events happening in FS during a single call, and I've been studying the Channel Events/States and the correlation between them. Very useful. I recommend every new ESL developer to do this. I do have a small question. When using the SendMSG method of ESLConnection to playback a file, the below sequence of events is generated. Now my question is: is there a way to send some unique string with the sendmsg command and have that one appear in all the other events which are shown below. I need to track the events which share a relationship. CHANNEL_EXECUTE and CHANNEL_EXECUTE_COMPLETE contain a unique Application-UUID, which is good and could suffice, but I haven't found a way where I can relate the sendmsg command back to these two events. I know there is the Unique-ID header, but I'd like every action to be uniquely identifiable. Is that possible or am I asking way too much? "Command": "sendmsg c48f66c0-e5be-11e3-a832-551ac922334e", "Event-Subclass": "c48f66c0-e5be-11e3-a832-551ac922334e", "call-command": "execute", "execute-app-name": "playback", "execute-app-arg": "/usr/src/freeswitch/sounds/basic/welcome.wav", "event-lock": "true", "Event-Name": "PRIVATE_COMMAND", "Event-Name": "CHANNEL_EXECUTE", "Application": "playback", "Application-Data": "/usr/src/freeswitch/sounds/basic/welcome.wav", "Application-UUID": "ca0df0a8-e5be-11e3-a83e-551ac922334e" "Event-Name": "PLAYBACK_START", "Playback-File-Path": "/usr/src/freeswitch/sounds/basic/welcome.wav", "Event-Name": "PLAYBACK_STOP", "Playback-File-Path": "/usr/src/freeswitch/sounds/basic/welcome.wav", "Playback-Status": "done" "Event-Name": "CHANNEL_EXECUTE_COMPLETE", "Application": "playback", "Application-Data": "/usr/src/freeswitch/sounds/basic/welcome.wav", "Application-Response": "FILE PLAYED", "Application-UUID": "ca0df0a8-e5be-11e3-a83e-551ac922334e"