Using Sound Card for Paging

[Tony Davis]

Has anyone had any experience setting up the sound card as an extension
for paging. There is a good article on this
 
http://www.voip-info.org/wiki/view/Setting+up+paging+with+a+sound+card
 
however, I am using Trixbox 1.1.? and it seems that a number of the
directories have moved or been replaced since the article was written.
As an example, there is no /usr/src/asterisk directory.