Dozens of vendors market Wi-Fi products, and organizations of every size and type are considering, if not deploying, wireless LANs. Now that wireless LANs have become mainstream, organizations want to tightly integrate wireless LANs with wired LANs. Network managers are reluctant or unwilling to deploy wireless LANs unless those LANs provide the type of security, manageability, and scalability offered by wired LANs. The chief concern is security, which encompasses access control and privacy. Access control ensures that sensitive data can be accessed only by authorized users.
Privacy ensures that transmitted data can be received and understood only by the intended audience.
Therefore, access control for a wired LAN often is viewed in terms of physical access to LAN ports. Similarly, because data transmitted on a wired LAN is directed to a particular destination, privacy cannot be compromised unless someone uses specialized equipment to intercept transmissions on their way to their destination. In short, a security breach on a wired LAN is possible only if the LAN is physically compromised. With a wireless LAN, transmitted data is broadcast over the air using radio waves, so it can be received by any wireless LAN client in the area served by the data transmitter. Because radio waves travel through ceilings, floors, and walls, transmitted data may reach unintended recipients on different floors and even outside the building of the transmitter.