I am experienced in Open Source VoIP Systems - Asterisk-Linux based, Call Center VoIP Systems (CDR & Recording, Realime Web Access on recordings), MySQL Databases, Asterisk VoIP-Dialplan,Call routing, A2Billing systems, Linux (CentOS-RedHat&Ubuntu),Intrusion Detection System Linux-Fail2Ban (SSH, Web-Apache, MySQL, Asterisk jails-services protect, GeoIP information of attacks etc), writing bash/perl scripts for different needs (alarming solutions via SMS or Phone Call, backup solutions between multiple Servers , monitoring tools for different services on many servers/equipments).
Webmin tool installation for managing on graphical interface the Linux server