Active channel events are sended every time a channel is added, removed or changed.
1 phone call can have a lot of channel events. Channel events are currently only usefull for the active calls list.
The phone call is identified with the callid, when 2 or more channels are having the same call id, these are the participants of the call.
There are 2 types of channel events (insert and remove), to process everything correctly you will always have to remove the channel first from your client and only add it when the type 'insert' received.

Before the active channel events can be processed, the current active channels needs to be determined.
This can be done by calling the active channels request from the API.

Check out the active calls demo, to check how to process the incoming channel events.