http://www.asterisk.org/downloads/yum
only shows a partial list of packages. The webpage format truncates the command string.
For example, my browser shows:
yum install asterisk16 asterisk16-configs asterisk16-voicemail dahdi-linux dahdi
look at the source for the yum install page shows:
yum install asterisk16 asterisk16-configs asterisk16-voicemail dahdi-linux dahdi-tools libpri