The extensions.conf config file is used to route incoming connections from remote nodes or connections to the correct node number in app_rpt. It also is used to route outgoing autopatch connections to various channels and VOIP termination providers.
Contexts used by app-rpt
[iax-client] - used by IAX users
[radio] - used for IAX connections between nodes
[check_route] - used to check the call routing for autopatch
[allstar-sys] - used by the phone portal
[allstar-public] - used by web transceiver
Here is an example of how extensions.conf is used to handle incoming connections for a single node:
[radio-secure] exten => 1234,1,rpt,1234
In the above case, two nodes are defined as asterisk extensions in a “context” called radio-secure defined by a stanza [radio-secure] . An incoming connection directed to extension 1234 will end up calling app_rpt (rpt) with a value of 1234 which should a node number defined in rpt.conf.