Install , configure , and support an organization 's local area network ( LAN ), wide area network ( WAN ), and Internet systems or a segment of a network system . Monitor network to ensure network availability to all system users and may perform necessary maintenance to support network availability . May monitor and test Web site performance to ensure Web sites operate correctly and without interruption . May assist in network modeling , analysis , planning , and coordination between network and data communications hardware and software . May supervise computer user support specialists and computer network support specialists . May administer network security measures .