Resource Modules

Resources provide functionality to Asterisk that may be called upon at any time during a call, even while another application is running on the channel. Resources are typically used as asynchronous events such as playing hold music when a call gets placed on hold, or performing call parking.

Resource modules have file names that looks like res_xxxxx.so, such as res_musiconhold.so.

Resource modules can provide Dialplan Applications and Dialplan Functions even if those apps or functions don't have separate modules.