regcontext (channel)
By specifying the context that contains the actions to perform, you can configure
Asterisk to perform a number of actions when a peer registers to your server.
This option works in conjunction with regexten, by specifying the extension to
execute. If no regexten is configured, the peer name is used as the extension.
Asterisk will dynamically create and destroy a NoOp at priority 1 for the extension.
All actions to be performed upon registration should start at priority 2.
More than one regexten may be supplied, if separated by an &. regcontext can be
set on a per-peer basis or globally.
regcontext=registered-phones

regexten (channel)
The regexten option is used in conjunction with regcontext to specify the extension
to be executed within the configured context. If regexten is not explicitly
configured, the peer name is used as the extension to match.
regexten=myphone