Basic FreePBX (Asterisk) Operations


Here are some basic operations of your Asterisk (FreePBX) server.

Any information provided here regarding "Asterisk" or "FreePBX" servers refers only to Telos-commissioned FreePBX (Asterisk) servers used with Telos Alliance telephony products. While these are third-party servers and software, we are able to provide limited pointers and advice (like this article) under normal support. 

We are also happy to provide advanced, dedicated support and training on a VX and FreePBX system through various paid TelosCare Service Level Agreement options, or a la carte via our Dedicated Remote and Onsite Support service. Please use the Contact Us link above for more information on these options. We can guide you through this entire process.

This article is meant to be a quick reference. There are exhaustive procedures, instructions, descriptions, and tutorials available on the wiki page for Asterisk here:


If removing power is required, your FreePBX server should always be shutdown gracefully using the following method:

  1. Open a terminal window.
  2. At the command prompt type:  shutdown -h now
  3. The server will halt and power off. The power LED on the front of the unit will do dark when the shutdown is finished.


Your FreePBX (Asterisk) server is regarded as highly stable. In our experience, restarting the server is almost never beneficial when attempting to resolve an issue. It is best to find the root problem, which is rarely the FreePBX server or software itself.

If you do need to restart the FreePBX server, use the following method:

  1. Open a terminal window.
  2. At the command prompt type:  shutdown -r now
  3. The server will restart. This will take 5-7 minutes.

Boot up

To start the server while it is powered down, press the power button on the front of the server. It may be behind a door.

Once fully booted (5-7 minutes), you will be presented with a login prompt.

The server will function completely (process calls) even if you do not log in with the below steps. The server does not require any manual intervention for normal operation once booted.

Accessing the desktop

  1. If you are being presented with a login prompt, enter the username and password provided after commissioning.
  2. Enter command startx. The desktop will load.

Using TeamViewer

During commissioning, if allowed by the customer, a Telos engineer will typically set up TeamViewer unattended operation. If the server is rebooted, this TeamViewer access may not be possible until the following steps are taken. Follow these steps to re-allow a Telos support engineer access to your server for remote assistance.

  1. Follow the Accessing the Desktop steps above if desktop is not currently displayed.
  2. Using the menu bar at the top of the screen, navigate to Applications > Internet. Click TeamViewer.
  3. If you are presented with a windows telling you the Teamviewer daemon is not started, press OK and go to step a. Otherwise, go to step 4.
    1. Open a terminal window.
    2. Type command teamviewer --daemon start (note there are two dashes, and the spelling of daemon).
    3. Press enter. You should be presented with the message teamviewerd start/running. If you receive an error, check the spelling and case of the above command.
    4. Repeat step 2.
  4. Send the displayed ID and password to the Telos support engineer.

Identify an Ethernet Interface

This is a defacto Linux command for identifying a network port:

ethtool -p eth0 120

This command will make the activity LEDs on the ethernet port named eth0 flash on and off for 120 seconds. You can make the port flash for longer or shorter by changing the value of the number at the end of the command.

Accessing Asterisk CLI (remote console)

The Asterisk command line interface (CLI) is reached by using the Linux shell command

asterisk -r

For more verbose output, add one or more "v"s to the "-r" parameter.

Full context of the Asterisk CLI is far beyond the scope of this article. That's OK because there's way more information here:

SIP Debug

You can collect SIP debug information from asterisk by using the following command:

sip set debug on

Full context of this utility can be found on the asterisk wiki here:

When debugging is complete and you want to stop the utility, use the alternate command:

sip set debug off

TCP Dump / Packet Capture

It is possible to take a packet capture from the command line if the system supports tcpdump. In such cases, the following syntax is used:

tcpdump -i any -w capture.pcap

Pressing Enter after keying in this command will begin the capturing process. Press Ctrl+C to stop the capture.

Use, or replace "any" with the name of the interface to be captured from.

Use, or replace "capture.pcap" with the desired name for your packet capture file. This file will be saved in the directory within which this command is run. You may want to use an SSH utility such as WinSCP to retrieve the pcap file from the system for analysis.

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