Page 791 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

Conducting a Site Survey

One method used to discover areas of a physical environment where
unwanted wireless access might be possible is to perform a site survey.
A site survey is the process of investigating the presence, strength, and
reach of wireless access points deployed in an environment. This task
usually involves walking around with a portable wireless device, taking

note of the wireless signal strength, and mapping this on a plot or
schematic of the building.

Site surveys should be conducted to ensure that sufficient signal
strength is available at all locations that are likely locations for
wireless device usage, while at the same time minimizing or
eliminating the wireless signal from locations where wireless access
shouldn’t be permitted (public areas, across floors, into other rooms,

or outside the building). A site survey is useful for evaluating existing
wireless network deployments, planning expansion of current
deployments, and planning for future deployments.

Using Secure Encryption Protocols

The IEEE 802.11 standard defines two methods that wireless clients
can use to authenticate to WAPs before normal network
communications can occur across the wireless link. These two
methods are open system authentication (OSA) and shared key
authentication (SKA). OSA means there is no real authentication
required. As long as a radio signal can be transmitted between the
client and WAP, communications are allowed. It is also the case that
wireless networks using OSA typically transmit everything in clear

text, thus providing no secrecy or security. SKA means that some form
of authentication must take place before network communications can
occur. The 802.11 standard defines one optional technique for SKA
known as Wired Equivalent Privacy (WEP). Later amendments to the
original 802.11 standard added WPA, WPA2, and other technologies.

WEP

Wired Equivalent Privacy (WEP) is defined by the IEEE 802.11

standard. It was designed to provide the same level of security and