Here's general dialplan concepts:
- Dialplan decides what FreeSWITCH will do with/to an incoming (audio/video) call
- Dialplan is a list of unrelated patterns
- Each individual pattern has its own individual list of actions
- The call "enters" the dialplan from beginning, and proceeds toward dialplan end
- The call tries to "match" each pattern in turn, from first to last
- If the call "matches" a pattern, then the list of actions of this pattern is added to the call TODO list
- At the end of dialplan traversal, the TODO list is executed
- Matching (or non matching) an individual pattern can be cause for stopping traversing the dialplan (that is, not try to match any successive pattern)
- The name "EXTENSION", in FreeSWITCH parlance, designatesanindividual PATTERN complete with its own set of ACTIONS
- Examples of individual patterns: (call destination number is between 1000 and 1019 and time of call is between 10 and 11 in the morning), (call is incoming from network 192.168.1.0/24), (call is not coming from network 192.168.1.0/24), (call is from a specific DID), (call is coming from a Firefox Browser and is a WebRTC call and destination number begins with 852), (call is coming from an internal SIP phone)
- Examples of action lists: (answer, play a sound file to caller, hangup), (answer, play a sound to caller, monitor which DTMFs the caller presses, react to those DTMFs by doing a database query and playing different sounds based on query results, hangup), (answer, monitor for fax tone, if tone is present then receive fax, else transfer call to operator), (answer, join the call to a videoconference)