Definitive Kamailio for engineers
5.0(3)Debian system administration
5.0(3)CentOS system administration
5.0(3)Suse system administration
5.0(3)Ubuntu system administration
5.0(3)Red Hat system administration
5.0(3)Linux system administration (LPIC-1)
5.0(3)Linux for network engineers
5.0(3)UNIX system administration
5.0(3)Concise Mikrotik routers for engineers
5.0(3)