The Network Administrator is responsible for the computer network. He manages workstations, user accounts, Internet connectivity, including routers, modems, firewalls, proxy, virtual private networks (VPN). Depending on the type of organization, the Network Administrator is also in charge of telephony (conventional, VoIP, Mobile). Sometimes the Network Administrator can also act as System Administrator and manages servers (Windows, Linux / Unix). Common tasks of the Network Administrator include: Network cable management (physical connection between several machines), routing management (logical connection between inside and outside the network or across multiple subnets), security management (antivirus, firewall, intrusion prevention etc.), management of user access rights (network access, etc.).