[Asterisk-Users] Alert extensions without answering incoming call?

[John Todd]

>Hi, * gurus,
>
>I wonder if there is a way to alert the in-house extension(s) in case of an
>incoming external call without actually answering it, before somebody picks
>up the phone on one of the extensions? This way the caller wouldn't have to
>pay for the call until somebody answers.
>
>Regards,
>Christian Lademann

The Cisco 79xx series phones in SIP mode have a "distinctive ring" 
that can be triggered from within Asterisk using the "ALERT_INFO" 
variable.  They are the only phones that I am aware of that support 
this SIP standard variable.

JT