1 The Asterisk(R) Open Source PBX
2 by Mark Spencer <markster@digium.com>
3 and the Asterisk.org developer community
5 Copyright (C) 2001-2006 Digium, Inc.
6 and other copyright holders.
7 ================================================================
10 It is imperative that you read and fully understand the contents of
11 the security information file (doc/security.txt) before you attempt
12 to configure and run an Asterisk server.
15 Asterisk is an Open Source PBX and telephony toolkit. It is, in a
16 sense, middleware between Internet and telephony channels on the bottom,
17 and Internet and telephony applications at the top. For more information
18 on the project itself, please visit the Asterisk home page at:
20 http://www.asterisk.org
22 In addition you'll find lots of information compiled by the Asterisk
23 community on this Wiki:
25 http://www.voip-info.org/wiki-Asterisk
27 There is a book on Asterisk published by O'Reilly under the
28 Creative Commons License. It is available in book stores as well
29 as in a downloadable version on the http://www.asteriskdocs.org
32 * SUPPORTED OPERATING SYSTEMS
35 The Asterisk Open Source PBX is developed and tested primarily on the
36 GNU/Linux operating system, and is supported on every major GNU/Linux
40 Asterisk has also been 'ported' and reportedly runs properly on other
41 operating systems as well, including Sun Solaris, Apple's Mac OS X, and
46 First, be sure you've got supported hardware (but note that you don't need
47 ANY special hardware, not even a soundcard) to install and run Asterisk.
49 Supported telephony hardware includes:
51 * All Wildcard (tm) products from Digium (www.digium.com)
52 * QuickNet Internet PhoneJack and LineJack (http://www.quicknet.net)
53 * any full duplex sound card supported by ALSA or OSS
54 * any ISDN card supported by mISDN on Linux (BRI)
55 * The Xorcom AstriBank channel bank
56 * VoiceTronix OpenLine products
58 The are several drivers for ISDN BRI cards available from third party sources.
59 Check the voip-info.org wiki for more information on chan_capi and
62 * UPGRADING FROM AN EARLIER VERSION
64 If you are updating from a previous version of Asterisk, make sure you
65 read the UPGRADE.txt file in the source directory. There are some files
66 and configuration options that you will have to change, even though we
67 made every effort possible to maintain backwards compatibility.
69 In order to discover new features to use, please check the configuration
70 examples in the /configs directory of the source code distribution.
71 To discover the major new features of Asterisk 1.2, please visit
72 http://edvina.net/asterisk1-2/
76 Ensure that your system contains a compatible compiler and development
77 libraries. Asterisk requires either the GNU Compiler Collection (GCC) version
78 3.0 or higher, or a compiler that supports the C99 specification and some of
79 the gcc language extensions. In addition, your system needs to have the C
80 library headers available, and the headers and libraries for OpenSSL,
82 On many distributions, these files are installed by packages with names like
83 'glibc-devel', 'ncurses-devel', 'openssl-devel' and 'zlib-devel' or similar.
87 1) Read this README file.
89 There are more documents than this one in the doc/ directory.
90 You may also want to check the configuration files that contain
91 examples and reference guides. They are all in the configs/
96 Execute the configure script to guess values for system-dependent
97 variables used during compilation.
99 3) Run "make menuselect" [optional]
101 This is needed if you want to select the modules that will be
102 compiled and to check modules dependencies.
106 Assuming the build completes successfully:
108 5) Run "make install"
110 Each time you update or checkout from the repository, you are strongly
111 encouraged to ensure all previous object files are removed to avoid internal
112 inconsistency in Asterisk. Normally, this is automatically done with
113 the presence of the file .cleancount, which increments each time a 'make clean'
114 is required, and the file .lastclean, which contains the last .cleancount used.
116 If this is your first time working with Asterisk, you may wish to install
117 the sample PBX, with demonstration extensions, etc. If so, run:
121 Doing so will overwrite any existing config files you have.
123 Finally, you can launch Asterisk in the foreground mode (not a daemon)
128 You'll see a bunch of verbose messages fly by your screen as Asterisk
129 initializes (that's the "very very verbose" mode). When it's ready, if
130 you specified the "c" then you'll get a command line console, that looks
135 You can type "help" at any time to get help with the system. For help
136 with a specific command, type "help <command>". To start the PBX using
137 your sound card, you can type "dial" to dial the PBX. Then you can use
138 "answer", "hangup", and "dial" to simulate the actions of a telephone.
139 Remember that if you don't have a full duplex sound card (and Asterisk
140 will tell you somewhere in its verbose messages if you do/don't) then it
141 won't work right (not yet).
143 "man asterisk" at the Unix/Linux command prompt will give you detailed
144 information on how to start and stop Asterisk, as well as all the command
145 line options for starting Asterisk.
147 Feel free to look over the configuration files in /etc/asterisk, where
148 you'll find a lot of information about what you can do with Asterisk.
150 * ABOUT CONFIGURATION FILES
152 All Asterisk configuration files share a common format. Comments are
153 delimited by ';' (since '#' of course, being a DTMF digit, may occur in
154 many places). A configuration file is divided into sections whose names
155 appear in []'s. Each section typically contains two types of statements,
156 those of the form 'variable = value', and those of the form 'object =>
157 parameters'. Internally the use of '=' and '=>' is exactly the same, so
158 they're used only to help make the configuration file easier to
159 understand, and do not affect how it is actually parsed.
161 Entries of the form 'variable=value' set the value of some parameter in
162 asterisk. For example, in chan_dahdi.conf, one might specify:
166 in order to indicate to Asterisk that the switch they are connecting to is
167 of the type "national". In general, the parameter will apply to
168 instantiations which occur below its specification. For example, if the
169 configuration file read:
171 switchtype = national
177 the "national" switchtype would be applied to channels one through
178 four and channels 10 through 12, whereas the "dms100" switchtype would
179 apply to channels 25 through 47.
181 The "object => parameters" instantiates an object with the given
182 parameters. For example, the line "channel => 25-47" creates objects for
183 the channels 25 through 47 of the card, obtaining the settings
184 from the variables specified above.
186 * SPECIAL NOTE ON TIME
188 Those using SIP phones should be aware that Asterisk is sensitive to
189 large jumps in time. Manually changing the system time using date(1)
190 (or other similar commands) may cause SIP registrations and other
191 internal processes to fail. If your system cannot keep accurate time
192 by itself use NTP (http://www.ntp.org/) to keep the system clock
193 synchronized to "real time". NTP is designed to keep the system clock
194 synchronized by speeding up or slowing down the system clock until it
195 is synchronized to "real time" rather than by jumping the time and
196 causing discontinuities. Most Linux distributions include precompiled
197 versions of NTP. Beware of some time synchronization methods that get
198 the correct real time periodically and then manually set the system
201 Apparent time changes due to daylight savings time are just that,
202 apparent. The use of daylight savings time in a Linux system is
203 purely a user interface issue and does not affect the operation of the
204 Linux kernel or Asterisk. The system clock on Linux kernels operates
205 on UTC. UTC does not use daylight savings time.
207 Also note that this issue is separate from the clocking of TDM
208 channels, and is known to at least affect SIP registrations.
212 Depending on the size of your system and your configuration,
213 Asterisk can consume a large number of file descriptors. In UNIX,
214 file descriptors are used for more than just files on disk. File
215 descriptors are also used for handling network communication
216 (e.g. SIP, IAX2, or H.323 calls) and hardware access (e.g. analog and
217 digital trunk hardware). Asterisk accesses many on-disk files for
218 everything from configuration information to voicemail storage.
220 Most systems limit the number of file descriptors that Asterisk can
221 have open at one time. This can limit the number of simultaneous
222 calls that your system can handle. For example, if the limit is set
223 at 1024 (a common default value) Asterisk can handle approxiately 150
224 SIP calls simultaneously. To change the number of file descriptors
225 follow the instructions for your system below:
227 == PAM-based Linux System ==
229 If your system uses PAM (Pluggable Authentication Modules) edit
230 /etc/security/limits.conf. Add these lines to the bottom of the file:
232 root soft nofile 4096
233 root hard nofile 8196
234 asterisk soft nofile 4096
235 asterisk hard nofile 8196
237 (adjust the numbers to taste). You may need to reboot the system for
238 these changes to take effect.
240 == Generic UNIX System ==
242 If there are no instructions specifically adapted to your system
243 above you can try adding the command "ulimit -n 8192" to the script
244 that starts Asterisk.
248 See the doc directory for more documentation on various features. Again,
249 please read all the configuration samples that include documentation on
250 the configuration options.
252 Finally, you may wish to visit the web site and join the mailing list if
253 you're interested in getting more information.
255 http://www.asterisk.org/support
257 Welcome to the growing worldwide community of Asterisk users!
262 Asterisk is a trademark belonging to Digium, inc