By default, all system extensions use a 'default' context. To use other contexts, you must create a new 'Custom Extension':
- Login to the system administration
- Navigate to 'Extensions: Custom'
- Click on 'Add Custom Extension'
- Set 'Extension'='1002' (Extension number)
- Set 'Context'='test' (new 'test' context)
- Click on 'Save'
- Navigate to 'System → Conf Files'
- Click on 'Extensions'
- Add the following lines to the bottom
[test]
exten => 1002,1,Answer()
exten => 1002,2,Playback(hello-world)
exten => 1002,3,Hangup()
- Click on 'Save'
- Click on 'Restart'
Now if any system extension dials '1002', it will playback the 'hello-world' sound file