Requirement
"Security mechanisms, service levels and service requirements of network services shall be identified, implemented and monitored."[1]
Explanation
Network security covers network authentication encryption in transit and monitoring the use of network services. Organizations should control remote access to their network by requiring authentication and protecting remote connections using encryption (e.g. IP Sec). Network authentication such as requiring 802.1x authentication or a pre-shared key should also be addressed. Other important topics include blocking or restricting certain network services such as only allowing HTTP HTTPS POP3 and SMTP traffic into the network.