I wanna install kamailio packages on Ubuntu 11.10. I've found a tutorial for installing kamailio but I'm facing problems installing packages after adding the repository lines to /etc/apt/sources.list and using:

apt-get install kamailio kamailio-mysql-modules kamailio-tls-modules

The following message appear:

E: Unable to locate package kamailio

E: Unable to locate package kamailio-mysql-modules    

E: Unable to locate package kamailio-tls-modules

this is the link for the
tutorial