Ian's Blog: Installing asterisk 10 realtime

Installing asterisk 10 realtime

2012-09-04 11:28 by Ian

Pre-requisites and forward

This is a brief guide to setting up asterisk on a generic linux host. This particular guide was written using CentOS 6. The process and configuration have been checked for accuracy on CentOS 6, Debian, and Gentoo. I have tried to indicate steps where such differences are relevant,

A resonably recent linux installation.
Depending on several factors, your hardware requirements will vary. I have implemented similarly-configured builds of asterisk on hardware as limited as a Raspberry Pi with good results.
About 3 hours, depending on how fast your box can compile.

Helpful resources:

Asterisk can be an intimidating package. It helps to have read some introductory material first. O'Reilly Media has delivered, and made freely-available Asterisk™: The Definitive Guide. It is worth the time you spend to read it cover-to-cover.
Once you have the basics under control, there is The Asterisk Documentation. When in doubt, those pages are canon.

Installation

Initial System Setup

Be advised… You will need to adjust this command to your distro. Debian has a very similar tool called apt-get, arch uses pacman, and gentoo uses portage.

Also, for CentOS users: if you are on a Xen VM, you will need to fetch kernel-xen-devel, rather than kernel-devel.

Also, for CentOS users: if you are compiling on x86_64, you will probably need to soft-link your MySQL libraries to /usr/lib/mysql. CentOS is somewhat dumb about which libs get installed. Usually it will install both i386 and x86_64 unless you specify which you want. LD is somewhat dumb about which libs to use if both are present. So make sure the only ones that get installed are the ones that match your architecture. I have not encountered this problem on any other distribution.

Some of this is my personal taste. If your server is going to be exposed to the internet, I would strongly recommend fail2ban, for instance. You know what's best for your box, but HDD is cheap these days, so rock on...

yum install mysql mysql-server mysql-devel curl curl-devel kernel-headers openssl openssl-devel speex speex-devel php php-bcmath php-gd php-imap php-mbstring php-mcrypt php-mysql php-odbc mysql-connector-odbc unixODBC-devel unixODBC flac libvorbis libvorbis-devel alsa-lib-devel alsa-lib alsa-utils httpd kernel-devel gcc make gcc-c++ libxml2 libxml2-devel bzip2-devel bzip2 perl ncurses-devel libtool-ltdl-devel libao-devel libao monit vsftpd subversion fail2ban sqlite-devel sqlite mlocate mod_ssl

That about covers the software that is typically available from baseline repositories. For CentOS (and I'm sure other distros) there exist binary repositories aimed at asterisk users. That being said, there are numerous advantages to building your own binaries, and I will continue assuming you are doing this.

Building the non-repo software

Using a telco interface card? Not without DAHDI, you aren't:

wget http://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/releases/dahdi-linux-complete-2.6.1+2.6.1.tar.gz
tar zxvf dahdi-linux-*
cd dahdi-linux-*
make
make install
cd ..

Note that the MeetMe conferance bridge also requires DAHDI, but asterisk 10 has deprecated MeetMe in favor of a new conferance bridge that takes better advantage of the extended media system. The new bridge does not require DAHDI.

Most casual users of VoIP don't understand that it is not simply SIP. SIP is the control and session-initiation channel. The actual stream that carries the voice (or video) is actually called RTP (Realtime Transport Protocol). If you want your communication to be encrypted, you will need to install the SRTP library...

wget http://srtp.sourceforge.net/srtp-1.4.2.tgz
tar zxvf srtp-1.4.2.tgz
cd srtp
./configure
make CFLAGS=-fPIC
make install
cd ..

Jabber support (and arbitrary handset-to-handset messages) needs a special XML library:

wget http://iksemel.googlecode.com/files/iksemel-1.4.tar.gz 
tar zxvf iksemel-1.4.tar.gz
cd iksemel-1.4
./configure
make
make install
cd ..

The speex codec was split into two packages for the 1.2 release. If you want to compile Asterisk against it, you will need to download the source from xiph.org and install it yourself…

wget http://downloads.xiph.org/releases/speex/speex-1.2rc1.tar.gz
tar zxvf speex-1*
cd speex-1*
./configure

Optionally, setup vsftpd and disable anonymous login…

vi /etc/vsftpd/vsftpd.conf

If you are going to be using FTP to upload to the new server, you will need to disable SELinux...

vi /etc/selinux/config

Change this line…

SELINUX=enforcing

To this…

SELINUX=permissive

Add our basic services to the group of services to be launched on startup…

chkconfig monit on
chkconfig mysqld on
chkconfig vsftpd on
chkconfig httpd on

Configure asterisk

The first step is to download asterisk. While you are there, have a look at their other packages and decide if you need any of them.
Once you have the tarball, extract it and enter the directory.

I will usually run the script to download the third-party mp3 CODEC at this point.

cd asterisk*
./configure
contrib/scripts/get_mp3_source.sh
make menuconfig

There are numerous configuration options for the build. If you want database-driven configuration, CDR, and Voicemail, you will need to select those things at this step. Also, you can opt to download sound-packages. Once you have finished choosing the particulars of your build, compile asterisk. If you have a multicore CPU, I would highly recommend the "-j" switch to distribute the workload across multiple CPUs. I usually use the number of cores in the machine.

make -j4

If that worked with no complaints, you can now install asterisk with....

make install

If you are doing this for the first time, you might want to...

make samples

...to build the example configuration files. We will be replacing most of these later, but the samples have lots of excellent documentation in them. They will also give you an idea about possibilities that you may not have imagined before.

If you want SILK support, go here and select the binary that most-closely matches your architecture, and copy it into your asterisk module directory.

At this point I also configure monit to keep the service alive.

Create a new file….

vi /etc/monit.d/asterisk.monit

…and into it, paste this…

check process asterisk
        with pidfile /var/run/asterisk/asterisk.pid
        start program = "/usr/sbin/asterisk_start"
        stop program = "/usr/sbin/asterisk_stop"

Now, create the wrapper scripts that are referenced in the above monit define…
The startup script...

touch /usr/sbin/asterisk_start
chmod +x /usr/sbin/asterisk_start
vi /usr/sbin/asterisk_start

#!/bin/bash
nohup asterisk 2>&1 &

And my corresponding shutdown script...

touch /usr/sbin/asterisk_stop
chmod +x /usr/sbin/asterisk_stop
vi /usr/sbin/asterisk_stop

#!/bin/bash 
asterisk -rx "core stop now"

Configuring asterisk

A brief aside on how I have configured asterisk

There is much documentation and many forum posts over the past 8 years and 5 major asterisk versions. The most reliable documentation I've found has been the extensive commentary present in many of the configuration files for the version in question. Most of the options in the config files seem to be transposable into the database (at least, those that I have tried thus far). For the purposes of this page, I have built asterisk to store VoiceMail, CDR (Call Detail Records), and SIP users in the database. The database definition for the SIP users was arrived at via a great deal of trial and error. It is known to be compatible with asterisk 1.8, and there appears to be leniency with respect to the number of fields from sip.conf that are reflected in the DB. Any fields defined in the table must have the same name as the field in sip.conf. The sip.conf file is still loaded and used, but any of the fields that are also defined in the database will override the values given in the conf file.

All of that being said, my database definition is given here (ast_table_defs.sql). If you wish to replicate my configuration, you will need this file later.

My sip.conf file reads thusly (/etc/asterisk/sip.conf):

[general]
context=default                 ; Default context for incoming calls
allowguest=no                  ; Allow or reject guest calls (default is yes)
allowoverlap=no                 ; Disable overlap dialing support. (Default is yes)

tcpenable=yes                    ; Enable server for incoming TCP connections (default is no)
udpbindaddr=0.0.0.0             ; IP address to bind UDP listen socket to (0.0.0.0 binds to all)
tcpbindaddr=0.0.0.0             ; IP address for TCP server to bind to (0.0.0.0 binds to all interfaces)
bindport=5060

srvlookup=yes                   ; Enable DNS SRV lookups on outbound calls
engine=asterisk                ; RTP engine to use when communicating with the device

If you downloaded the SILK module earlier, you should make sure that something to this effect resides in your codecs.conf file (/etc/asterisk/codecs.conf):

[silk8]
type=silk
samprate=8000
fec=true
packetloss_percentage=10
maxbitrate=20000
dtx=false

[silk12]
type=silk
samprate=12000
fec=true
packetloss_percentage=10
maxbitrate=25000
dtx=false

[silk16]
samprate=16000
fec=true
packetloss_percentage=10
maxbitrate=30000
dtx=false

[silk24]
samprate=24000
fec=true
packetloss_percentage=10
maxbitrate=40000
dtx=false

Creating the database

First we should start the mysql service and set a password. Typically, we will also want the DB to start on boot.

service mysqld start
mysqladmin -u root password 'change_this_to_your_password'
chkconfig --level 2345 mysqld on

Now we need to open the MySQL console and create users, DB's, and permissions.

mysql -u root -p

Once logged into the mysql server, we need to define our DB. I usually....

source ast_table_defs.sql

...where ast_table_defs.sql is the file you may have downloaded earlier. I decline to paste this file text here, because it is too large to paste into an SSH window for most clients.

Add yourself a user, and also one for the local asterisk user.

Depending on your MySQL version, these queries may fail because they contain the wrong number of fields for the user table. If anyone explains why, I can fix the queries and remove this box. :-)

USE mysql;
insert into user values
('localhost','asterisk',PASSWORD('PLAINTEXT_PASSWORD'),'N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','','','','',0,0,0,0),
('%','asterisk',PASSWORD('PLAINTEXT_PASSWORD'),'N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','N','','','','',0,0,0,0);

insert into db values
	('localhost','ast_db','asterisk','Y','Y','Y','Y','Y','N','N','Y','Y','Y','Y','Y','Y','Y','N','N','N','N','N'),
	('%','ast_db','asterisk','Y','Y','Y','Y','Y','N','N','Y','Y','Y','Y','Y','Y','Y','N','N','N','N','N');

FLUSH PRIVILEGES;

Configure ODBC

Next, we need to setup ODBC so that Asterisk can use MySQL…

This is written with CentOS 6 in mind. Gentoo does the ODBC dance a little differently. I recommend that if these instructions do not work on your gentoo build, review This section of the ODBC documentation, and verify that your odbc.ini and odbcinst.ini files are being read from /etc/, and not /etc/unixODBC. If the latter, adjust your paths appropriately. Also verfiy that the driver name in your DSN matches the MySQL driver's name in odbcinst.ini.

vi /etc/odbc.ini

[asterisk]
Description=Asterisk config and log.
Driver=MySQL
Server=localhost
Database=ast_db
User=asterisk
Password=PLAINTEXT_PASSWORD
Port=3306
Option=3

Next, we need to tell Asterisk which data it should look for in the DB, and the names of the tables in which it is stored…

vi /etc/asterisk/extconfig.conf

[settings]
sipusers => odbc,asterisk,sipfriends
sippeers => odbc,asterisk,sipfriends
voicemail => odbc,asterisk,voiceboxes

OBDC Resource config file…

vi /etc/asterisk/res_odbc.conf

[ENV]
[asterisk]
enabled => yes
dsn => asterisk
username => asterisk
password => PLAINTEXT_PASSWORD
pre-connect => yes
sanitysql => select 1
idlecheck => 3600
share_connections => yes
backslash_is_escape => no

MySQL Config File…

vi /etc/asterisk/res_config_mysql.conf

[general]
dbhost = 127.0.0.1
dbname = ast_db
dbuser = asterisk
dbpass = PLAINTEXT_PASSWORD
dbport = 3306
dbsock = /tmp/mysql.sock
dbcharset = latin1

Add a few users...

All of this work will be completely useless without users. Let's add 4 of them for now. Log back into MySQL and run this query to insert 4 users...

USE ast_db;
INSERT INTO `voiceboxes` VALUES (4,'103','default','103','1234',NULL,NULL,NULL,'central','yes','yes',NULL,NULL,'no','no','no','no',1,'no','no','yes','no','no','yes','2012-01-26 20:27:01'),
(3,'102','default','102','1234',NULL,NULL,NULL,'central','yes','yes',NULL,NULL,'no','no','no','no',1,'no','no','yes','no','no','yes','2012-01-26 20:27:01'),
(2,'101','default','101','1234',NULL,NULL,NULL,'central','yes','yes',NULL,NULL,'no','no','no','no',1,'no','no','yes','no','no','yes','2012-01-26 20:27:01'),
(1,'100','default','100','1234',NULL,NULL,NULL,'central','yes','yes',NULL,NULL,'no','no','no','no',1,'no','no','yes','no','no','yes','2012-01-26 20:27:01');

INSERT INTO `sipfriends` VALUES 
	(1,'100','',0,'100',NULL,NULL,'',0,'dynamic','peer','users',NULL,NULL,'PASS0',NULL,NULL,NULL,'inband','no','comedia',NULL,NULL,'en','gsm;speex;ulaw;alaw;ilbc;speex16',NULL,NULL,'no',NULL,NULL,NULL,NULL,NULL,'Ext 100',NULL,NULL,NULL,'no',NULL,NULL,NULL,NULL,'100@novoicemail.com',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no',NULL,30,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no','no',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,5,NULL,NULL,NULL,NULL,NULL,'yes'),
	(2,'101','',0,'101',NULL,NULL,'',0,'dynamic','peer','users',NULL,NULL,'PASS1',NULL,NULL,NULL,'inband','no','comedia',NULL,NULL,'en','gsm;speex;ulaw;alaw;ilbc;speex16',NULL,NULL,'no',NULL,NULL,NULL,NULL,NULL,'Ext 101',NULL,NULL,NULL,'no',NULL,NULL,NULL,NULL,'101@novoicemail.com',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no',NULL,30,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no','no',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,5,NULL,NULL,NULL,NULL,NULL,'yes'),
	(3,'102','',0,'102',NULL,NULL,'',0,'dynamic','peer','users',NULL,NULL,'PASS2',NULL,NULL,NULL,'inband','no','comedia',NULL,NULL,'en','gsm;speex;ulaw;alaw;ilbc;speex16',NULL,NULL,'no',NULL,NULL,NULL,NULL,NULL,'Ext 102',NULL,NULL,NULL,'no',NULL,NULL,NULL,NULL,'102@novoicemail.com',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no',NULL,30,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no','no',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,5,NULL,NULL,NULL,NULL,NULL,'yes'),
	(4,'103','',0,'103',NULL,NULL,'',0,'dynamic','peer','users',NULL,NULL,'PASS3',NULL,NULL,NULL,'inband','no','comedia',NULL,NULL,'en','gsm;speex;ulaw;alaw;ilbc;speex16',NULL,NULL,'no',NULL,NULL,NULL,NULL,NULL,'Ext 103',NULL,NULL,NULL,'no',NULL,NULL,NULL,NULL,'103@novoicemail.com',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no',NULL,30,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,'no','no',NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,5,NULL,NULL,NULL,NULL,NULL,'yes');

Define a simple dial-plan...

The dial-plan (/etc/asterisk/extensions.conf) on one of my test machines reads like this:

[stations]
  exten => _1XX,1,Wait(2)
  exten => _1XX,n,Set(DIALEDEXT=${EXTEN})
  exten => _1XX,n,Dial(SIP/${DIALEDEXT},20)
  exten => _1XX,n,Goto(${DIALSTATUS},1)
  exten => _1XX,n,Hangup

  exten => ANSWER,1,Hangup()
  exten => CANCEL,1,Hangup()

  exten => NOANSWER,1,Voicemail(${DIALEDEXT}@default,u)
  exten => NOANSWER,n,Hangup()

  exten => BUSY,1,Voicemail(${DIALEDEXT}@default,b)
  exten => BUSY,n,Hangup()

  exten => CONGESTION,1,Voicemail(${DIALEDEXT}@default,u)
  exten => CONGESTION,n,Hangup()

  exten => CHANUNAVAIL,1,Voicemail(${DIALEDEXT}@default,u)
  exten => CHANUNAVAIL,n,Hangup()

[voicemail]
  exten => 000,1,Wait(1)
  exten => 000,n,VoicemailMain(${CALLERID(num)}@default,a)
  exten => 000,n,Hangup

[users]
include => voicemail
include => stations

The setup is simple. Four SIP users with voice mail. No conference rooms. No trunking. Whole applications can be written here, and this topic will be covered here in the future. But not now.

Test the installation

Run asterisk in (5)very verbose mode:

asterisk -cvvvvv

Examine the output for WARNING tags. If your scrollback buffer isn't large enough, the same output will be appended to the asterisk log file, which can be tailed in this way:

tail -f /var/log/asterisk/messages

Some general tips and a command cheat sheet:

core show translation

Performance notes:

ARM6 (Raspberry Pi)

core show translation
         Translation times between formats (in microseconds) for one second of data
          Source Format (Rows) Destination Format (Columns)

            gsm  ulaw  alaw  g726 adpcm  slin lpc10 speex speex16  ilbc g726aal2  g722 slin16 testlaw speex32 slin12 slin24 slin32 slin44 slin48 slin96 slin192
      gsm     - 15000 15000 15000 15000  9000 15000 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
     ulaw 15000     -  9150 15000 15000  9000 15000 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
     alaw 15000  9150     - 15000 15000  9000 15000 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
     g726 15000 15000 15000     - 15000  9000 15000 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
    adpcm 15000 15000 15000 15000     -  9000 15000 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
     slin  6000  6000  6000  6000  6000     -  6000  6000   14000  6000     6000  8250   8000    6000   14000   8000   8000   8000   8000   8000   8000    8000
    lpc10 15000 15000 15000 15000 15000  9000     - 15000   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
    speex 15000 15000 15000 15000 15000  9000 15000     -   23000 15000    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
  speex16 23500 23500 23500 23500 23500 17500 23500 23500       - 23500    23500 15000   9000   23500   23000  17500  17000  17000  17000  17000  17000   17000
     ilbc 15000 15000 15000 15000 15000  9000 15000 15000   23000     -    15000 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
 g726aal2 15000 15000 15000 15000 15000  9000 15000 15000   23000 15000        - 17250  17000   15000   23000  17000  17000  17000  17000  17000  17000   17000
     g722 15600 15600 15600 15600 15600  9600 15600 15600   15000 15600    15600     -   9000   15600   23000  17500  17000  17000  17000  17000  17000   17000
   slin16 14500 14500 14500 14500 14500  8500 14500 14500    6000 14500    14500  6000      -   14500   14000   8500   8000   8000   8000   8000   8000    8000
  testlaw 15000 15000 15000 15000 15000  9000 15000 15000   23000 15000    15000 17250  17000       -   23000  17000  17000  17000  17000  17000  17000   17000
  speex32 23500 23500 23500 23500 23500 17500 23500 23500   23500 23500    23500 23500  17500   23500       -  17500  17500   9000  17000  17000  17000   17000
   slin12 14500 14500 14500 14500 14500  8500 14500 14500   14000 14500    14500 14000   8000   14500   14000      -   8000   8000   8000   8000   8000    8000
   slin24 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500   14000   8500      -   8000   8000   8000   8000    8000
   slin32 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500    6000   8500   8500      -   8000   8000   8000    8000
   slin44 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500   14500   8500   8500   8500      -   8000   8000    8000
   slin48 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500   14500   8500   8500   8500   8500      -   8000    8000
   slin96 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500   14500   8500   8500   8500   8500   8500      -    8000
  slin192 14500 14500 14500 14500 14500  8500 14500 14500   14500 14500    14500 14500   8500   14500   14500   8500   8500   8500   8500   8500   8500       -

Previous: Automotive Isolation Box
Next: Building a FIPS capable OpenSSL (Gentoo)

Ian's Blog

Oh god... how did this get here? I am not good with computer.

Installing asterisk 10 realtime

Category list

Identity