The purpose of this system is the automated testing of all accounts which can receive calls, with the Echo() application. It is based on a bash script which creates a call file and an extension in the dialplan. Basically when the system is started the script selects all users, starts calling (via call files) them one after another. This is very basic example of the "reverse application manipulation".

Before running through the core of this tutorial, let's make some small preparations for it.

The setup that we are going to use has the following properties: the system should find all users for curtain channel (iax2 or sip). Every user is been called by the Asterisk and is been greeted with announcement one. We will set an absolute timeout to two minutes (120 seconds). After that the Echo() application is going to start in order to make the test. If the user hangs up, Asterisk will do nothing, and the system is going to call the next user. If the user press the pound key, the system is going to run a program or script which will notify us for the problem.

Step 3.1: Creating the needed extensions
Let's create the extension that we are going to use. Since we are going to use a call file, there is no significance where (at which context) the extension will be placed. For this tutorial we will create a special context named `echotest`. Here what you have to do:

	Open your extensions.conf using a text redactor.
	At the bottom of the file (on new line) add new context by typing `[echotest]` (without the quotes).
	Add the following extension:
		exten => echo,1,Answer()
			; Answer the line
		exten => echo,n,Set(TIMEOUT(absolute)=120)
			; Sets maximum length of the call to two minutes (if someone forgets to hang up)
		exten => echo,n,Playback(file1)
			; Playbacks file named `f1`. The user will hear the contents of `f1`
			; In our tutorial `f1` is the first announcement that we have recorded.
		exten => echo,n,Echo()
			; starting Echo() application which will create the echo effect
		exten => echo,n,Playback(f2)
			; Playbacks file named `f2`. The user will hear the contents of `f2`
			; In our tutorial `f2` is the first announcement that we have recorded.
		exten => echo,n,System(/bin/notify_us ${CUR})
			; Notification script which will notify us that curtain user is experiencing problems.
		exten => echo,n,HangUp()
			; Hangs up the call.

Here is an screenshot of what it should look like:


This extension is very usefull even if you use it alone (without the script). If the user follows the instructions, there are two possible outcomes:

Remark: if you have only write access to /etc/asterisk/extensions.conf , create somewhere a file in which write the context and the extension. Then run the command:

		`cat /route/to/somewhere/file >> /etc/asterisk/extensions.conf`

where `/route/to/somewhere/file` is the path and the file in which you have written the thing.


Step 3.2: Preparation for the creation of call files
Now let's create a prototype for our call files. We will create it in /var/spool/asterisk/ directory. However the location of the prototype is not important for script (the location have to differs important dirs like `/dev`, `/boot`, `/var/spool/asterisk/outgoing`, etc...).

	Context: echotest
		# Asterisk will execute extension in this string
	Extension: echo
		# Name of the extension
	Priority: 1
		# At which priority Asterisk will begin the execution
	Callerid: Automated Test System <>
		# Setting the CallerID to the specified string.

If you copy/paste the protoype file, notice that you have to remove the comments marked with #. Asterisk will not escape those comments, and their might lead to unexpected results. The file should look like this one:You may notice that the only not optional keyword for the call files (Channel: CHAN/USER) is missing. Don't worry we will not make with this file. We will just use it for creation of the actual call files. We will use this prototype call file with the filename `echotest.org.call` at the following directory: /var/spool/asterisk/ echotest-$i.call;

Step 3.3: Making a list of people to call
Now let's create a small bash script which will make the whole work for us.
We will need to get all users which are added to our configuration files. There are two ways to do this:



Both methods have both pros and cons:



Run the script in the following way:
./echotest iax to test IAX2 users
./echotest sip to test SIP users


`example2`


Run the script in the following way:
./echotest IAX2 to test IAX2 users
./echotest SIP to test SIP users

Step 3.4: Improve the scripts to reduce the amount of extensions we forgot to call

`example1`


Run the script in the following way:
./echotest iax to test IAX2 users
./echotest sip to test SIP users


`example2`


Run the script in the following way:
./echotest IAX2 to test IAX2 users
./echotest SIP to test SIP users



The second version of those scripts were upgraded in some ways:
configuration file parsing - recurse search and parse of included files
configuration file parsing - script will place a message on the console for every user it calls
configuration file parsing - script will place a message on the console for file it starts to parse
console output - escape most of the messages by temporally setting the VERBOSE level to 0
configuration file parsing - script will place a message on the console for every user it calls

I am sure that the reader of this tutorial will try to modify these scripts. That's why I will leave some notifications which will help you:
SetVar: CUR=$1/$i - is setting a variable in the dialplan so Asterisk will be able to notify (in some way) that a problem occurred with curtain user
sleep 121; - removing this line may case the following problem - Asterisk will try to dial too much calls and might crash.
sleep 121; - setting a different value to the sleep command may cause the following bug - Asterisk will change the ${CUR} variable and if the user presses the pound key, you might be notified for an other user.