How to use Variables and Global Variables on Asterisk Dialplan Context

TO USE VARIABLES AND GLOBAL VARIABLES ON ASTERISK DIALPLAN CONTEXT

Introduction:

Asterisk can help you define your own patterns for call flow that will help regulate any unforeseen changes and optimize your communication system. Asterisk can use global, shared, and channel-specific variables for arguments to commands. There are variables that Asterisk automatically introduces.

Installation Steps:

Step 1: Check the OS version by using the below command

root@linuxhelp1:~# lsb_release -a
No LSB modules are available.
Distributor ID:    Ubuntu
Description:    Ubuntu 22.04.2 LTS
Release:    22.04
Codename:    jammy

Step 2: Check the status of the Asterisk by using the below command

root@linuxhelp1:~# lsb_release -a
root@linuxhelp1:~# systemctl status asterisk
● asterisk.service - LSB: Asterisk PBX
     Loaded: loaded (/etc/init.d/asterisk; generated)
     Active: active (running) since Tue 2023-07-25 07:27:52 IST; 21min ago
       Docs: man:systemd-sysv-generator(8)
    Process: 1408 ExecStart=/etc/init.d/asterisk start (code=exited, status=0/SUCCESS)
      Tasks: 71 (limit: 4537)
     Memory: 131.6M
        CPU: 16.600s
     CGroup: /system.slice/asterisk.service
             └─1432 /usr/sbin/asterisk

Jul 25 07:27:52 linuxhelp1 systemd[1]: Starting LSB: Asterisk PBX...
Jul 25 07:27:52 linuxhelp1 asterisk[1408]:  * Starting Asterisk PBX: asterisk
Jul 25 07:27:52 linuxhelp1 asterisk[1408]:    ...done.
Jul 25 07:27:52 linuxhelp1 systemd[1]: Started LSB: Asterisk PBX.
Jul 25 07:27:59 linuxhelp1 asterisk[1432]: radcli: rc_read_config: rc_read_config: can't open /etc/radiusclient-ng/>
Jul 25 07:27:59 linuxhelp1 asterisk[1432]: radcli: rc_read_config: rc_read_config: can't open /etc/radiusclient-ng/>

Step 3: Move to the Asterisk directory by using the below command

root@linuxhelp1:~# cd /etc/asterisk/

Step 4: Show the endpoints in the pjsip.conf file by using the below command

root@linuxhelp1:/etc/asterisk# vim pjsip.conf

Step 5: Open extensions.conf file to edit the dialplan using variables by using the below command

root@linuxhelp1:/etc/asterisk# vim extensions.conf

Step 6: Login to the Asterisk CLI mode by using the below command

root@linuxhelp1:/etc/asterisk# asterisk -rvvvvvvvvvvvvvvvvvvvvvv
Asterisk 20.3.1, Copyright (C) 1999 - 2022, Sangoma Technologies Corporation and others.
Created by Mark Spencer <markster@digium.com>
Asterisk comes with ABSOLUTELY NO WARRANTY; type 'core show warranty' for details.
This is free software, with components licensed under the GNU General Public
License version 2 and other licenses; you are welcome to redistribute it under
certain conditions. Type 'core show license' for details.
=========================================================================
Connected to Asterisk 20.3.1 currently running on linuxhelp1 (pid = 1432)

Step 7: Reload the dialplan by using the below command

linuxhelp1*CLI> dialplan reload
Dialplan reloaded.
[Jul 25 07:55:00] WARNING[6905]: pbx_config.c:1955 pbx_load_config: ==!!== Unknown directive: ringtime at line 3 of extensions.conf -- IGNORING!!!
    -- Including switch 'Lua/' in context 'local'
    -- Including switch 'Lua/' in context 'demo'
    -- Including switch 'Lua/' in context 'default'
    -- Including switch 'Lua/' in context 'public'


    -- Including switch 'DUNDi/e164' in context 'ael-dundi-e164-switch'
    -- Time to scan old dialplan and merge leftovers back into the new: 0.000680 sec
    -- Time to restore hints and swap in new dialplan: 0.000045 sec
    -- Time to delete the old dialplan: 0.000163 sec
    -- Total time merge_contexts_delete: 0.000888 sec
    -- pbx_config successfully loaded 27 contexts (enable debug for details).

Step 8: Exit from the Asterisk CLI by using the below command

linuxhelp1*CLI>
Disconnected from Asterisk server
Asterisk cleanly ending (0).
Executing last minute cleanups

Step 9: Again, login to the extension.conf to use channel variable by using the below command

root@linuxhelp1:/etc/asterisk# vim extensions.conf

Step 10: Login to the Asterisk CLI mode and reload the dialplan by using the below command

root@linuxhelp1:/etc/asterisk# asterisk -rvvvvvvvvvvvvvvvvvvvvvv
Asterisk 20.3.1, Copyright (C) 1999 - 2022, Sangoma Technologies Corporation and others.
Created by Mark Spencer <markster@digium.com>
Asterisk comes with ABSOLUTELY NO WARRANTY; type 'core show warranty' for details.
This is free software, with components licensed under the GNU General Public
License version 2 and other licenses; you are welcome to redistribute it under
certain conditions. Type 'core show license' for details.
=========================================================================
Connected to Asterisk 20.3.1 currently running on linuxhelp1 (pid = 1432)

linuxhelp1*CLI> dialplan reload
Dialplan reloaded.
[Jul 25 07:57:43] WARNING[7246]: pbx_config.c:1955 pbx_load_config: ==!!== Unknown directive: ringtime at line 3 of extensions.conf -- IGNORING!!!
    -- Including switch 'DUNDi/e164' in context 'ael-dundi-e164-switch'
    -- Including switch 'Lua/' in context 'public'
    -- Including switch 'Lua/' in context 'default'
    -- Including switch 'Lua/' in context 'demo'
    -- Including switch 'Lua/' in context 'local'
    -- Time to scan old dialplan and merge leftovers back into the new: 0.000437 sec
    -- Time to restore hints and swap in new dialplan: 0.000007 sec
    -- Time to delete the old dialplan: 0.000091 sec
    -- Total time merge_contexts_delete: 0.000535 sec
    -- pbx_config successfully loaded 27 contexts (enable debug for details).

Conclusion:

We have reached the end of this article. In this guide, we have walked you through the steps how to use Variables and Global Variables on Asterisk Dialplan Context. Your feedback is much welcome.