10.5. Call Files

Call files allow you to create calls through the Linux shell. These powerful events are triggered by depositing a .call file in the directory /var/spool/asterisk/outgoing/. The actual name of the file does not matter, but it's good form to give the file a meaningful name and to end the filename with .call.

Figure 10-1. The Flash Operator Panel management interface

When a call file appears in the outgoing folder, Asterisk will almost immediately^[*] act on the instructions contained therein.

^[*] We're talking seconds or less.

Call files are formatted in the following manner. First, we define where we want to call:

    Channel: <channel>

We can control how long to wait for a call to be answered (the default is 45 seconds), how long to wait between call retries, and the maximum number of retries. If MaxRetries is omitted, the call will be attempted only once:

    WaitTime: <number>
    RetryTime: <number>
    MaxRetries: <number>

If the call is answered, we specify where to connect it here:

    Context: <context-name>
    Extension: <ext>
    Priority: <priority>

Alternatively, we can specify a single application and pass arguments to it:

    Application: Playback( )
    Data: hello-world

Next, we set the Caller*ID of the outgoing call:

    CallerID: Asterisk <800-555-1212>

Then we set channel variables, as follows:

    SetVar: john=Zap/1/5551212
    SetVar: sally=SIP/1000

and add a CDR account code:

    Account: documentation

When you create a call file, do not do so from the spool directory. Asterisk monitors the spool aggressively and will try to grab your file before you've even finished writing it. Create call files in some other folder, and then mv them into the spool directory.