[Asterisk-Users] Can you invoke an app before dialtone?

[John Todd]

>say I needed to send a broadcast message that I wanted every user to
>hear when the pick up thier phone?  can I "Play,message" on a line just
>before they get dialtone?  or maybe after they dial before ring?  how
>about a "ringdown" to a voicemail box and on end return them to thier
>line for the dialout?   can * do ringdowns?  when a user picks up an
>extension it automagically rings an extension?
>
>Dave

This depends on the hardware you're using.  A SIP phone (or H323 or 
MGCP) will normally wait until a certain number of digits or a 
timeout before sending the dial request to the * server.  You can (in 
Cisco's example, at least) create a PLAR (Private Line Auto-Ringdown) 
which will dial a specified number the moment the phone goes off the 
hook.  This could lead into an extension that auto-plays a series of 
messages and then re-provides dial tone via a DISA application.  So, 
in short, yes, Asterisk can do what you want if your desktop hardware 
understands auto-ringdowns.

Even if they don't understand PLAR, you can still play a message 
after the user dials and before the call is actually "dialed".  This 
is a simple matter of variable setting in the correct order.

If you are using Zap hardware (analog lines going into a Digium 
4-port FXS card or into a channel bank and then into a T100P card) 
then use the immediate= line commented on in a previous post.

JT