OpenMicroServer Implementation

VoIP Server with Asterisk

  1. Asterisk
  2. Express Talk
  3. Checking the Installation

The following document describes how to set up an OpenMicroServer (OMS) as a server for VoIP telephony (SIP server). We use Asterisk, an open source telephony tool kit to act as the server software, and Express Talk, a free VoIP software, for the client.

We assume a basic setup with two PCs on a local network. To build this basic connection, we need:

Asterisk

Asterisk is a leading open source telephony engine and tool kit. It allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network (PSTN). It was originially created by Mark Spencer, and is released under GNU General Public License (GPL).

Preparing the MicroServer

To install asterisk on your OpenMicroServer, you need to fit the server with a CompactFlash card in the internal slot, or a USB thumb drive or hard disk and install the firmware on that device. The standard internal flash ROM is not big enough to hold Asterisk.

See the OMS User's Guide on how to install firmware on a flash card / HDD.

Firmware

OpenMicroServer Firmware Remote directory

Download Asterisk

Precompiled packages of Asterisk are available for the OpenMicroServer.

OpenMicroServer

The disk space needed for the installation of Asterisk is about 100 MB.

Installing Asterisk

Enter the following to start the installation: 

# tar zxpvf asterisk-1.4.4-mipsel-1.tgz -C /
# tar zxpvf net-snmp-5.3.0.1-mipsel-1.tgz -C /
# /sbin/ldconfig

Configuration

Assuming there are the SIP server (OpenMicroServer) and two Windows PCs on our network.

Example Network
Host IP address
SIP Server 192.168.0.1
PC1 192.168.0.100
PC2 192.168.0.200
SIP Numbers
PC SIP Number
PC1 100
PC2 200

Configuration files

/usr/local/etc/asterisk/sip.conf

Add the following lines to the end of the file, /usr/local/etc/asterisk/sip.conf. 

[100]
type=friend
secret=plathome
username=user100
host=dynamic

[200]
type=friend
secret=plathome
username=user200
host=dynamic

/usr/local/etc/asterisk/extensions.conf

In the “;default” category of the file, /usr/local/etc/asterisk/extensions.conf, change as follows.

Old: include => demo
New: ;include => demo

Add the following lines to the “;default” category of the file, /usr/local/etc/asterisk/extensions.conf.

exten => 100,1,Dial(SIP/100,12)
exten => 100,2,Congestion
exten => 100,102,Busy

exten => 200,1,Dial(SIP/200,12)
exten => 200,2,Congestion
exten => 200,102,Busy

exten => _.,1,Answer()
exten => _.,2,Wait(2)
exten => _.,3,Playback(pbx-invalid)
exten => _.,3,Congestion

Express Talk

Express Talk VoIP Softphone is a free VoIP software from NCH Swift Sound, available for Windows PC and Mac.

Installation on Windows PC

Download the installation file from the Express Talk VoIP Softphone Homepage and install it to the PC. Also connect microphone and speaker.

Below are the necessary settings to use Express Talk with Asterisk installed on OpenMicroServer or OpenBlockS266.

Express Talk (Options ?> Lines) PC1 PC2
Settings for Line Default Line Settings
Full 'Friendly' Display Name user100 user200
Server (SIP Proxy or Virtual PBX) 192.168.0.1
SIP Number (or User Name) 100 200
Password plathome plathome

Checking the Installation

Once you have set up your server and clients, you can log in to the OMS and start the asterisk server to create a test connection.

Start Asterisk

Type the following command on the OpenMicroServer

# asterisk

Talk

Start Express Talk on PC1 and PC2. Call and Talk.

Stop Asterisk

Type the following command on the OpenMicroServer

# asterisk -r

The prompt, CLI, is displayed. Type the following command. 

CLI> stop gracefully

Contact

If you have questions concerning this installation, please contact Plat'Home USA Ltd. support@plathome.com