Using templates

You can use templates in your Asterisk configuration files (e.g. in sip.conf) to avoid repetitive sections. To appreciate their usefulness, consider the following code:

[bob]
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

[alice]
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

[jack]
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

[hellen]
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

In the code above, we’ve defined parameters for each peer individually, even though they all hold the same values. This is where templates come into play – we can define a template containing these parameters and then apply it to each peer.

To define a template, we need to place an exclamation mark in parentheses after the section name, like this:

[internal-phones](!)

Now we can define the parameters that the template will contain:

[internal-phones](!)
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

To apply a template, we simply type the template name in parentheses after the device name, e.g.:

[hellen](internal-phones)

Now, our code will be much shorter, but will not lose any of the functionality:

[internal-phones](!)
type=friend
context=local
allow=ulaw,alaw
secret=verysecret1
host=dynamic
dtmfmode=rfc2833

[bob](internal-phones)

[alice](internal-phones)

[jack](internal-phones)

[hellen](internal-phones)