Page 192 - Asterisk™: The Future of Telephony

You must restart Asterisk after editing features.conf, as the file is read
only on startup. Running the reload command will not cause the
features.conf file to be read.

Also note that because the user needs to be able to transfer the calls to the parking lot
extension, you should make sure you’re using the t and/or T options to the Dial()
application.
So, let’s create a simple dialplan to show off call parking:
[incoming]
include => parkedcalls
exten => 103,1,Dial(SIP/Bob,,tT)
exten => 104,1,Dial(SIP/Charlie,,tT)
To illustrate how call parking works, say that Alice calls into the system and dials
extension 103 to reach Bob. After a while, Bob transfers the call to extension 700, which
tells him that the call from Alice has been parked in position 701. Bob then dials Charlie
at extension 104, and tells him that Alice is at extension 701. Charlie then dials exten-
sion 701 and begins to talk to Alice. This is a simple and effective way of allowing callers
to be transferred between users.

The t and T arguments to Dial() are not needed on all channel types.
For example, many SIP phones implement this via a softkey or hardkey
and utilize SIP signaling.

Conferencing with MeetMe()

Last but not least, let’s cover setting up an audio conference bridge with the MeetMe()
*
application. This application allows multiple callers to converse together, as if they
were all in the same physical location. Some of the main features include:
• The ability to create password-protected conferences
• Conference administration (mute conference, lock conference, kick participants)
• The option of muting all but one participant (useful for company announcements,
broadcasts, etc.)
• Static or dynamic conference creation
Let’s walk through setting up a basic conference room. The configuration options for
the MeetMe conferencing system are found in meetme.conf. Inside the configuration
file, you define conference rooms and optional numeric passwords. (If a password is

* In the world of legacy PBXes, this type of functionality is very expensive. Either you have to pay big bucks
for a dial-in service, or you have to add an expensive conferencing bridge to your proprietary PBX.

164 | Chapter 6: More Dialplan Concepts