Page 68 - Asterisk™: The Future of Telephony

Obtaining the Source Code

The best place to get source code for Asterisk and it’s packages is directly from the
http://www.asterisk.org web site or FTP server.

Release Versus Trunk
The Asterisk code base is under a constant state of change. Developers use a sofware
‡
revision tool called Subversion (SVN) to manage the code base. Subversion allows a
communty of developers to collaborate with each other on complex programming
projects.
There are two main areas where Asterisk is developed, and these are referred to as the
Branch and the Trunk. In the Trunk, new features, architectural changes, and any of
the brand-new stuff that is going on is performed. This place in the code base contains
all the new toys, but at any time can be in a nonworking state, and is absolutely for-
bidden from production use (see figure).

1.0 1.2 1.4

Trunk

Just like a tree, a Trunk will have Branches. These Branches have the major revision
numbers such as 1.0, 1.2, and 1.4 (in the future we will likely see 1.6, 1.8, 1.8.2, 1.8.4.
§
1.8.6, 1.8.8. 1.8.8.2…um…etc…). Within the Branch there are no major architectural
changes or new features—simply bug and security fixes. In a production environment,
stability is far more important than feature evolution.
Roughly every 14 months (although Asterisk does not follow a formal release timeline
like many commercial software packages), a version of Asterisk is released intended for
use in production environments. The first version of Asterisk was 1.0, which was re-
leased at the very first AstriCon in Atlanta in September of 2004. Asterisk 1.2 was
released at IP4IT in November 2005, and Asterisk 1.4 was released in December of
2006.

Obtaining Asterisk Source Code

The easiest way to obtain the most recent release is through the use of the program
wget.

‡ Subversion is an excellent code management system, available at http://subversion.tigris.org/. It also has an equally
excellent Creative Commons released book, Version Control with Subversion, by Ben Collins Sussman et al.
(O’Reilly), available online at http://svnbook.red-bean.com/.
§ As of the release date of this book, there has been no determination that the next Asterisk release will be 1.6. It
could just as easily be 2.0. Therefore, when discussing new features, you’ll see us talk about what’s in Trunk or
what will be in the next release—without mentioning the specific version.

40 | Chapter 3: Installing Asterisk