Music on Hold (MOH) is not a central component, and it's dependent on endpoints supporting it.
To download the default FreeSWITCH Music on Hold files at all the sample rates (8000, 16000, 32000, 48000) you must run this command inside the FreeSWITCH source directory:
Or just download the files freeswitch-sounds-music-RESOLUTION-VERSION.tar.gz directly from http://files.freeswitch.org/.
In conf/vars.xml the default is defined:
which points to sound files defined in conf/autoload_configs/local_stream.conf.xml
You can also generate tones for music on hold using the tone_stream app:
which is not very entertaining, but gets the point across.
You may also configure a unique music on hold for each sip profile, which is useful in multi-tenant environments.
How it works on the telephone
- Second incoming call comes in.
- Phone plays call waiting beep.
- User hits flash button.
- ATA sends a SIP INVITE message to FreeSWITCH, and in the SDP it says "sendonly"
- FreeSWITCH receives the SIP INVITE and plays the hold music (assuming correctly configured).