Page 141 - Asterisk™: The Future of Telephony

In the introduction to this section, we mentioned the possible bandwidth savings when
utilizing IAX2 trunking. It’s simple to enable this functionality in Asterisk, as we just
need to add trunk=yes to our friend definition. As long as a timing interface is installed
and running (i.e., dummy), then we can take advantage of IAX2 trunking.

The secret is straightforward: it’s our authentication password. We’re defining the
[incoming_osaka] context as the place we will process incoming calls for this friend in
the extensions.conf file. Finally, we block all IP addresses with the deny option from
being allowed to authenticate, and explicitly permit 192.168.1.107.
The iax.conf configuration for Osaka is nearly identical, except for the changes in IP
address and names:
[general]
autokill=yes

register => osaka:welcome@192.168.1.104
[toronto]
type=friend
host=dynamic
trunk=yes
secret=welcome
context=incoming_toronto
deny=0.0.0.0/0.0.0.0
permit=192.168.1.104/255.255.255.255

IAX Phone Configuration

In the “Configure the Softphone” section, we configured our first IAX2 softphone using
idefisk. The configuration we’ll be using here is nearly identical except for minor
changes in order to cause the peers to be unique. If you’ve already configured a SIP
softphone, then you can also utilize that on one (or both) of the peers. Remember that
Asterisk is a multiprotocol application, and you can send a call from a SIP phone to
Asterisk, across an IAX2 trunk, and then down to another SIP phone (or H.323, MGCP,
etc.).

On Osaka:
[1001]
type=friend
host=dynamic
context=phones
On Toronto:

[2001]
type=friend
host=dynamic
context=phones

Connecting Two Asterisk Boxes Together via IAX | 113