Asterisk Installation on OpenWRT

This guide refers to the package of Asterisk version 1.0.10,
tested on the WRT54GL hardware on the OpenWrt 0.9 GNU/Linux distribution, which you may find, for example, here

Index

• OpenWrt installation
• Preparing OpenWrt
• Installing Asterisk
• Get Asterisk to start at boot
• First execution of Asterisk
• Reboot and verify
• Configuring the Asterisk modules
• System optimization

OpenWrt installation

It’s possible to build your own OpenWrt distribution, customizing the kernel and the packages, by using this buildsystem.
Alternatively, follow this procedure to install a pre-built firmware:

• Download the most appropriate firmware for your router; with our hardware, for example, the file openwrt-wrt54g-squashfs.bin
• Be sure to be able to transmit to the router, for example with the command:
  ping 192.168.1.1
• Turn off the WRT54GL and run, from a Unix like box, the following command (all in one row):
  atftp --trace --option "timeout 1" --option "mode octet" --put --local-file openwrt-wrt54g-squashfs.bin 192.168.1.1
• Turn on the WRT54GL, which should automatically receive the new firmware and wait some minutes

If you have troubles or if you are installing from a different operating system or architecture, you can refer to this great guide

Preparing OpenWrt

• Now it should be possible to login in the new OpenWrt installation, with, in our case, the command:
  telnet 192.168.1.1
• It’s possible to set the root password by running passwd which wll also disable the telnet service in favor of the openbear server, which offers the ssh service
• To set the 4 LAN ports of the router to get the IP address automatically, by using the DHCP protocol, write the command:
  nvram set lan_proto=dhcpclient
  and then the command:
  nvram commit
  which will save the changes on the flash memory and apply them on the next reboot

Here you will find the documentation of the nvram options

Installing Asterisk

• Having the OpenWrt router connected to the Internet, update it’s packages database, by running:
  ipkg update
• Upgrade all the packages to the last version, by running:
  ipkg upgrade
• Install Asterisk by running:
  ipkg install asterisk

Get Asterisk to start at boot

If you want the Asterisk daemon to start at boot, modify with your favourite text editor the file /etc/default/asterisk changing the row:
ENABLE_ASTERISK=”no”
in
ENABLE_ASTERISK=”yes”

First execution of Asterisk

As the superuser root, from whatever folder you are in, run:
asterisk -vvvc
Asterisk will load it’s modules and it’s configuration, you should then read:
Asterisk Ready.
*CLI>
this is the command line interface of Asterisk, to logout run the command:
stop now

Reboot and verify

Reboot the system with the command:
reboot
after the reboot process, you can verify that Asterisk is running with the command:
asterisk -r
and logout from the command line interface with the command:
exit

Configuring the Asterisk modules

The default Asterisk configuration on OpenWrt disables some modules, in particular some codecs.
Modify in accordance with your needs the directives of the /etc/asterisk/modules.conf file, like, for example:
noload => codec_alaw.so
with
load => codec_alaw.so
obtaining a result similar to this

System optimization

• The WRT54GL has 4 MB of flash memory, which acts as an hard drive, and 16 MB of RAM.
  By installing Asterisk it will remain less than 1 MB of free space on the flash.
  It’s advisable to disable the logging of Asterisk, by changing with your favourite text editor the file /etc/asterisk/logger.conf, obtaining a result like this

  Also, those are some commands you may find useful:

  • It’s possible to view the partitions usage with the command: df -h
  • Obtain the list of the installed packages with the command: ipkg status|grep Package
  • Uninstall a package with the command, for example: ipkg remove asterisk
• Even more important is the RAM usage, because going out of RAM and SWAP will result in some service failure, or even a system crash (until the next reboot)

  Here are some commands you may find useful for monitoring memory usage:

  • It’s possible to view the memory usage with the command: free
  • How much memory is using a process with the command: ps
  • With the command top you will have a view, in real time, of the running processes, the CPU percentage usage, the memory usage and the total load on the system

This guide is also available in Italian