Page 468 - Asterisk™: The Future of Telephony

Transfer() Transfers the caller to a remote extension
Transfer([Technology/]destination[,options)

Requests that the remote caller be transferred to the given (optional Technology and)
destination. If the Technology is set to IAX2, SIP, Zap, etc., then transfer will happen
only if the incoming call is of the same channel type.
Upon completion, this application sets a channel variable named TRANSFERSTATUS to
one of the following values:
SUCCESS
The transfer was successful.
FAILURE
The transfer was not successful.
UNSUPPORTED
The transfer was not supported by the underlying channel driver.

If the options parameter is set to the letter j and the transfer is not supported or suc-
cessful, and there exists a priority n+101 (where n is the current priority), that priority
will be taken next.
; transfer calls from extension 123 to extension SIP/123@otherserver
exten => 123,1,Transfer(SIP/123@otherserver)

TryExec() Tries to execute an Asterisk application
TryExec(app(args))

Attempts to run the specified Asterisk application.
This application is very similar to the Exec() application, except that it always returns
normally, whereas the Exec() application will act as if the underlying application was
natively called, including exit status. This application can be used to catch a condition
that would normally cause the underlying application to exit abnormally.
exten => 123,1,TryExec(VMAuthenticate(@default))
See Also
Exec()

TrySystem() Tries to execute an operating system command
TrySystem(command)

Attempts to execute a command in the underlying operating system. The result of the
command will be placed in the SYSTEMSTATUS channel variable and will be one of the
following:

440 | Appendix B: Application Reference