--- 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.
--- 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
In addition you'll find lots of information compiled by the Asterisk community on this Wiki:
http://www.voip-info.org/wiki-Asterisk
--- 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.
--- 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
--- 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.
--- 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:
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
"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.
--- 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.
--- 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.
--- 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.
--- 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 ==
--- 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/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
--- Mark Spencer, and the Asterisk.org development community
Asterisk is a trademark of Digium, Inc.