如果linux不能用yum安装asterisk时，可以参照以下办法添加asterisk仓库

Installing a binary distribution of Asterisk makes it easier to maintain your system. Using the package management tools that are included with your Linux distribution, you can install and update software without manually managing dependencies (libraries and utilities on which applications rely). Currently Asterisk is available for automated binary installation using the 'yum' utility on CentOS 5 Linux and for RedHat Enterprise Linux 5.

The first step is to add the Asterisk yum repositories to your CentOS or RedHat system. This is done by creating an entry in the yum configuration directory (/etc/yum.repos.d by default).

Use the text editor of your choice to create a new file named "centos-asterisk.repo" in the "/etc/yum.repos.d" folder. Add the following text to the file:

[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

Save the new file and create another named "centos-digium.repo" and insert the following text:

[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

At this point your system has been updated to use the Asterisk and Digium repositories in addition to the base CentOS repositories. You are now ready to install Asterisk. To start the installation, execute the following at the Linux command line: