The Asterisk Open Source PBX
by Mark Spencer <email@example.com>
Copyright (C) 2001, Linux Support Services, Inc.
It is imperative that you read and fully understand the contents of
the SECURITY file before you attempt to configure an Asterisk server.
* WHAT IS ASTERISK
Asterisk is an Open Source PBX and telephony toolkit. It is, in a
sense, middleware between Internet and telephony channels on the bottom,
and Internet and telephony applications at the top. For more information
on the project itself, please visit the Asterisk home page at:
Asterisk is distributed under GNU General Public License. The GPL also
must apply to all loadable modules as well, except as defined below.
Linux Support Services, Inc. retains copyright to all of the core
Asterisk system, and therefore can grant, at its sole discression, the
ability for companies, individuals, or organizations to create proprietary
or Open Source (but non-GPL'd) modules which may be dynamically linked at
runtime with the portions of Asterisk which fall under our copyright
umbrella, or are distributed under more flexible licenses than GPL. At
this time (5/21/2001) the only component of Asterisk which is covered
under GPL and not under our Copyright is the Xing MP3 decoder.
If you wish to use our code in other GPL programs, don't worry -- there
is no requirement that you provide the same exemption in your GPL'd
products (although if you've written a module for Asterisk we would
strongly encourage you to make the same excemption that we do).
Specific permission is also granted to OpenSSL and OpenH323 to link to
If you have any questions, whatsoever, regarding our licensing policy,
please contact us.
* REQUIRED COMPONENTS
== Linux ==
Currently, the Asterisk Open Source PBX is only known to run on the
Linux OS, although it may be portable to other UNIX-like operating systems
* GETTING STARTED
First, be sure you've got supported hardware. To use Asterisk right now,
you will need one of the following:
* All Wildcard (tm) products from LSS (www.linux-support.net)
* QuickNet Internet PhoneJack and LineJack (http://www.quicknet.net)
* Full Duplex Sound Card supported by Linux
* Adtran Atlas 800 Plus
* ISDN4Linux compatible ISDN card
* Tormenta Dual T1 card (www.bsdtelephony.com.mx)
Assuming you have one of these (most likely the third) you're ready to
1) Run "make"
2) Run "make install"
If this is your first time working with Asterisk, you may wish to install
the sample PBX, with demonstration extensions, etc. If so, run:
Doing so will overwrite any existing config files you have.
Finally, you can launch Asterisk with:
You'll see a bunch of verbose messages fly by your screen as Asterisk
initializes (that's the "very very verbose" mode). When it's ready, if
you specified the "c" then you'll get a command line console, that looks
You can type "help" at any time to get help with the system. For help
with a specific command, type "help <command>". To start the PBX using
your sound card, you can type "dial" to dial the PBX. Then you can use
"answer", "hangup", and "dial" to simulate the actions of a telephone.
Remember that if you don't have a full duplex sound card (And asterisk
will tell you somewhere in its verbose messages if you do/don't) than it
won't work right (not yet).
Feel free to look over the configuration files in /etc/asterisk, where
you'll find a lot of information about what you can do with Asterisk.
* ABOUT CONFIGURATION FILES
All Asterisk configuration files share a common format. Comments are
delimited by ';' (since '#' of course, being a DTMF digit, may occur in
many places). A configuration file is divided into sections whose names
appear in 's. Each section typically contains two types of statements,
those of the form 'variable = value', and those of the form 'object =>
parameters'. Internally the use of '=' and '=>' is exactly the same, so
they're used only to help make the configuration file easier to
understand, and do not affect how it is actually parsed.
Entries of the form 'variable=value' set the value of some parameter in
asterisk. For example, in tormenta.conf, one might specify:
In order to indicate to Asterisk that the switch they are connecting to is
of the type "national". In general, the parameter will apply to
instantiations which occur below its specification. For example, if the
configuration file read:
switchtype = national
channel => 1-4
channel => 10-12
switchtype = dms100
channel => 25-47
Then, the "national" switchtype would be applied to channels one through
four and channels 10 through 12, whereas the "dms100" switchtype would
apply to channels 25 through 47.
The "object => parameters" instantiates an object with the given
parameters. For example, the line "channel => 25-47" creates objects for
the channels 25 through 47 of the tormenta card, obtaining the settings
from the variables specified above.
* MORE INFORMATION
Finally, you may wish to visit the web site and join the mailing list if
you're interested in getting more information.