Overview:
Asterisk allows people to communicate using the internet. It is one of the cheapest ways to talk. The PC clients connect to each other through an Asterisk server which uses a Linux/Unix OS.

Asterisk calls can be passed through different channel protocols. The most popular forms of calls are H323, SIP, IAX or Zap. Depending on the type of channel you use, the user must have the appropriate software to handle the call type.



SIP/IAX Client Configuration:
Now, we will describe how you can register SIP and IAX users. This includes the adjustment of all Asterisk and client phone settings.

First, make sure Asterisk is installed. Most of the files to be modified are stored in /etc/asterisk.

To make calls with this kind of telephone system you should have the following:


All configuration information for the Asterisk PBX knows is written to the conf files located in /etc/asterisk.



To place a call through Asterisk, registration to Asterisk is not required. However, you do need a username and password which will allow you to call someone who is registered.

To receive a call, you must be a registered user and have an extension.

To Register SIP Users:

All users must be registered in sip.conf and all valid extensions must be declared in extensions.conf

Follow these steps for:


1. Go to the /etc/asterisk directory on your Asterisk server. Open sip.conf and register the following test user.

Note that ALL characters after ‘;’ (semi-colomn) are interpreted by Asterisk as a comment.
[ivan]

type=friend

username=ivan

secret=pwd_ivan

host=dynamic

context=tutorial


This completes the user registration process on Asterisk. Now let us register an extension for the user.

2. Go to /etc/asterisk and open extensions.conf


[tutorial]

exten => 1234,1,Dial(SIP/ivan)


We now have a registered SIP user and extension on Asterisk. Follow this same process to register another SIP user and extension in order to place test calls.

Start by registering the second user in the same way in /etc/asterisk/sip.conf



Register the extension(4321) in /etc/asterisk/extensions.conf in the same context = tutorial.



Now when user 'ivan' or any other user from the tutorial context dials 4321, the user 'test' will be called.

3. The final step is to register the user to a compatible softphone. However, softphones will be reviewed later. For now, just make sure you have registered the users and extensions.

More detailed configuration information for a series of phones can be found here:

01. asterisk with softphones
02. asterisk with hardphones

To Register IAX Users: