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=== The Asterisk(R) Open Source PBX

===

=== by Mark Spencer <markster@digium.com>

=== and the Asterisk.org developer community

===

=== Copyright (C) 2001-2016 Digium, Inc.

=== and other copyright holders.

===============================================================================

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--- SECURITY ------------------------------------------------------------------

It is imperative that you read and fully understand the contents of

the security information document before you attempt to configure and run

an Asterisk server.

If you downloaded Asterisk as a tarball, see the security section in the PDF

version of the documentation in doc/tex/asterisk.pdf. Alternatively, pull up

the HTML version of the documentation in doc/tex/asterisk/index.html. The

source for the security document is available in doc/tex/security.tex.

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--- 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. However, Asterisk supports

more telephony interfaces than just Internet telephony. Asterisk also has a

vast amount of support for traditional PSTN telephony, as well. For more

information on the project itself, please visit the Asterisk home page at:

http://www.asterisk.org

The official Asterisk wiki can be found at:

https://wiki.asterisk.org

In addition you'll find lots of information compiled by the Asterisk

community on this Wiki:

http://www.voip-info.org/wiki-Asterisk

There is a book on Asterisk published by O'Reilly under the Creative Commons

License. It is available in book stores as well as in a downloadable version on

the http://www.asteriskdocs.org web site.

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--- SUPPORTED OPERATING SYSTEMS -----------------------------------------------

--- Linux

The Asterisk Open Source PBX is developed and tested primarily on the

GNU/Linux operating system, and is supported on every major GNU/Linux

distribution.

--- Others

Asterisk has also been 'ported' and reportedly runs properly on other

operating systems as well, including Sun Solaris, Apple's Mac OS X, Cygwin,

and the BSD variants.

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--- GETTING STARTED -----------------------------------------------------------

First, be sure you've got supported hardware (but note that you don't need

ANY special hardware, not even a sound card) to install and run Asterisk.

Supported telephony hardware includes:

* All Analog and Digital Interface cards from Digium (www.digium.com)

* QuickNet Internet PhoneJack and LineJack (http://www.quicknet.net)

* any full duplex sound card supported by ALSA, OSS, or PortAudio

* any ISDN card supported by mISDN on Linux

* The Xorcom Astribank channel bank

* VoiceTronix OpenLine products

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--- UPGRADING FROM AN EARLIER VERSION -----------------------------------------

If you are updating from a previous version of Asterisk, make sure you

read the UPGRADE.txt file in the source directory. There are some files

and configuration options that you will have to change, even though we

made every effort possible to maintain backwards compatibility.

In order to discover new features to use, please check the configuration

examples in the /configs directory of the source code distribution. For a

list of new features in this version of Asterisk, see the CHANGES file.

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--- NEW INSTALLATIONS ---------------------------------------------------------

Ensure that your system contains a compatible compiler and development

libraries. Asterisk requires either the GNU Compiler Collection (GCC) version

3.0 or higher, or a compiler that supports the C99 specification and some of

the gcc language extensions. In addition, your system needs to have the C

library headers available, and the headers and libraries for ncurses.

There are many modules that have additional dependencies. To see what

libraries are being looked for, see ./configure --help, or run

"make menuselect" to view the dependencies for specific modules.

On many distributions, these dependencies are installed by packages with names

like 'glibc-devel', 'ncurses-devel', 'openssl-devel' and 'zlib-devel'

or similar.

So, let's proceed:

1) Read this README file.

There are more documents than this one in the doc/ directory. You may also

want to check the configuration files that contain examples and reference

guides. They are all in the configs/ directory.

2) Run "./configure"

Execute the configure script to guess values for system-dependent

variables used during compilation.

3) Run "make menuselect" [optional]

This is needed if you want to select the modules that will be compiled and to

check dependencies for various optional modules.

4) Run "make"

Assuming the build completes successfully:

5) 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:

6) "make samples"

Doing so will overwrite any existing configuration files you have installed.

Finally, you can launch Asterisk in the foreground mode (not a daemon) with:

# asterisk -vvvc

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

like this:

*CLI>

You can type "core show help" at any time to get help with the system. For help

with a specific command, type "core show help <command>". To start the PBX using

your sound card, you can type "console dial" to dial the PBX. Then you can use

"console answer", "console hangup", and "console 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)

then it won't work right (not yet).

"man asterisk" at the Unix/Linux command prompt will give you detailed

information on how to start and stop Asterisk, as well as all the command

line options for starting Asterisk.

Feel free to look over the configuration files in /etc/asterisk, where you

will find a lot of information about what you can do with Asterisk.

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--- 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 dahdi.conf, one might specify:

switchtype=national

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

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 card, obtaining the settings

from the variables specified above.

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--- SPECIAL NOTE ON TIME ------------------------------------------------------

Those using SIP phones should be aware that Asterisk is sensitive to

large jumps in time. Manually changing the system time using date(1)

(or other similar commands) may cause SIP registrations and other

internal processes to fail. If your system cannot keep accurate time

by itself use NTP (http://www.ntp.org/) to keep the system clock

synchronized to "real time". NTP is designed to keep the system clock

synchronized by speeding up or slowing down the system clock until it

is synchronized to "real time" rather than by jumping the time and

causing discontinuities. Most Linux distributions include precompiled

versions of NTP. Beware of some time synchronization methods that get

the correct real time periodically and then manually set the system

clock.

Apparent time changes due to daylight savings time are just that,

apparent. The use of daylight savings time in a Linux system is

purely a user interface issue and does not affect the operation of the

Linux kernel or Asterisk. The system clock on Linux kernels operates

on UTC. UTC does not use daylight savings time.

Also note that this issue is separate from the clocking of TDM

channels, and is known to at least affect SIP registrations.

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--- FILE DESCRIPTORS ----------------------------------------------------------

Depending on the size of your system and your configuration,

Asterisk can consume a large number of file descriptors. In UNIX,

file descriptors are used for more than just files on disk. File

descriptors are also used for handling network communication

(e.g. SIP, IAX2, or H.323 calls) and hardware access (e.g. analog and

digital trunk hardware). Asterisk accesses many on-disk files for

everything from configuration information to voicemail storage.

Most systems limit the number of file descriptors that Asterisk can

have open at one time. This can limit the number of simultaneous

calls that your system can handle. For example, if the limit is set

at 1024 (a common default value) Asterisk can handle approximately 150

SIP calls simultaneously. To change the number of file descriptors

follow the instructions for your system below:

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--- PAM-based Linux System ----------------------------------------------------

If your system uses PAM (Pluggable Authentication Modules) edit

/etc/security/limits.conf. Add these lines to the bottom of the file:

root soft nofile 4096

root hard nofile 8196

asterisk soft nofile 4096

asterisk hard nofile 8196

(adjust the numbers to taste). You may need to reboot the system for

these changes to take effect.

== Generic UNIX System ==

If there are no instructions specifically adapted to your system

above you can try adding the command "ulimit -n 8192" to the script

that starts Asterisk.

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--- MORE INFORMATION ----------------------------------------------------------

See the doc directory for more documentation on various features. Again,

please read all the configuration samples that include documentation on

the configuration options.

If this release of Asterisk was downloaded from a tarball, then some

additional documentation should have been included.

* doc/tex/asterisk.pdf --- PDF version of the documentation

* doc/tex/asterisk/index.html --- HTML version of the documentation

Finally, you may wish to visit the web site and join the mailing list if

you're interested in getting more information.

http://www.asterisk.org/support

Welcome to the growing worldwide community of Asterisk users!

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--- Mark Spencer, and the Asterisk.org development community

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Asterisk is a trademark of Digium, Inc.