Create the Asterisk yum repositories and save it:

	# vi /etc/yum.repos.d/centos-asterisk.repo

	[asterisk-tested]
	name=CentOS-$releasever - Asterisk - Tested
	baseurl=http://packages.asterisk.org/centos/$releasever/tested/$basearch/
	enabled=0
	gpgcheck=0
	#gpgkey=http://packages.asterisk.org/RPM-GPG-KEY-Digium

	[asterisk-current]
	name=CentOS-$releasever - Asterisk - Current
	baseurl=http://packages.asterisk.org/centos/$releasever/current/$basearch/
	enabled=1
	gpgcheck=0
	#gpgkey=http://packages.asterisk.org/RPM-GPG-KEY-Digium

	# vi /etc/yum.repos.d/centos-digium.repo

	[digium-tested]
	name=CentOS-$releasever - Digium - Tested
	baseurl=http://packages.digium.com/centos/$releasever/tested/$basearch/
	enabled=0
	gpgcheck=0
	#gpgkey=http://packages.digium.com/RPM-GPG-KEY-Digium

	[digium-current]
	name=CentOS-$releasever - Digium - Current
	baseurl=http://packages.digium.com/centos/$releasever/current/$basearch/
	enabled=1
	gpgcheck=0
	#gpgkey=http://packages.digium.com/RPM-GPG-KEY-Digium

Install Asterisk and everything else:

	# yum -y install asterisk16 asterisk16-configs asterisk16-voicemail dahdi-linux dahdi-tools libpri

Test out the new install by starting Asterisk:

	# asterisk -vvvgci

Reference:
http://www.asterisk.org