Page 410 - Asterisk™: The Future of Telephony

; now delete the key family named test
exten => 123,3,DBdeltree(test)
See Also
DB_DELETE(), DBdel(), DB

DeadAGI() Executes an AGI-compliant script on a dead (hung-up) channel
DeadAGI(program,args)

Executes an AGI-compliant program on a dead (hung-up) channel. AGI allows Asterisk
to launch external programs written in almost any language to control a telephony
channel, play audio, read DTMF digits, and so on by communicating with the AGI
protocol on STDIN and STDOUT. The arguments specified by args will be passed to the
program.
This application has been written specifically for dead channels, as the normal AGI
interface doesn’t work correctly if the channel has been hung up.
Use the show agi command on the command-line interface to list all of the available
AGI commands.
exten => h,1,DeadAGI(agi-test)

See Also
AGI(), FastAGI()

Dial() Attempts to connect channels

Dial(tech/username:password@hostname/extension[&tech2/peer2...]
[,ring-timeout[,flags[,URL]]])
*
Allows you to connect together all of the various channel types. Dial() is the most
important application in Asterisk; you’ll want to read through this section a few times.
Any valid channel type (such as SIP, IAX2, H.323, MGCP, Local, or Zap) is acceptable
to Dial(), but the parameters that need to be passed to each channel will depend on
the information the channel type needs to do its job. For example, a SIP channel will
need a network address and user to connect to, whereas a Zap channel is going to want
some sort of phone number.

When you specify a channel type that is network-based, you can pass the destination
host (name or IP address), username, password, and remote extension as part of the

* The fact that Asterisk will happily connect IAX, SIP, H.323, Skinny, PRI, FX(O/S), and anything else is
amazing, but possibly the most amazing of all is the Local channel. By allowing a single Dial() command to
connect to multiple Local channels, one Dial() event can trigger a multitude of completely independent and
unique actions in other parts of the dialplan. The power of this concept is truly revolutionary and has to be
experienced to be believed.

382 | Appendix B: Application Reference