CISSP Practice

81. d. A mobile topology is similar to a cellular network because multiple base stations (BSs) collaborate to provide seamless communications over a distributed network to both subscriber stations (SSs) and mobile subscribers (MSs). A non-line-of-sight (NLOS) signal propagation is electromagnetic signaling that uses advanced modulation techniques to compensate for signal obstacles and enables indirect communications between transmitting stations. Mobile WiMAX topology operates on NLOS signal propagation, whereas the other three topologies use either LOS or NLOS signal propagation. A line-of-sight (LOS) signal propagation is electromagnetic signaling that is highly sensitive to radio frequency obstacles requiring an unobstructed view between transmitting stations. The other three choices are also examples of WiMAX operating topologies.

A point-to-point topology consists of a dedicated long-range, high-capacity wireless link between two sites. This topology is used for high-bandwidth wireless backhaul services at maximum operating ranges using either LOS or NLOS signal propagation. It uses a backhaul as a high-capacity line from a remote site or network to a central site or network.

A point-to-multipoint topology is composed of a central BS supporting multiple SSs, providing network access from one location to many locations. It is commonly used for last-mile broadband access, private enterprise connectivity to remote offices, and long-range wireless backhaul services for multiple sites. Last-mile broadband access refers to communications technology that bridges the transmission distance between the broadband service provider and the customer premises equipment.

A multihop relay topology, also referred to as mesh networking, is used to extend a BS’s coverage area by permitting SSs or MSs to replay traffic by acting as a relay station.

82. Which of the following worldwide interoperability for microwave access (WiMAX) operating topologies uses a concept of security zone?

a. Point-to-point

b. Point-to-multipoint

c. Multihop relay

d. Mobile

82. c. A multihop relay topology, also referred to as mesh networking, is used to extend a base station’s (BS) coverage area by permitting subscriber stations (SSs) or mobile subscribers (MSs) to replay traffic by acting as a relay station. A multihop uses a security zone concept where it is a set of trusted relationships between a BS and a group of relay stations (RSs). An RS can forward traffic to only RSs or SSs within its security zone. The other three choices, which are also examples of WiMAX operating topologies, do not use the concept of security zone.

A point-to-point topology consists of a dedicated long-range, high-capacity wireless link between two sites. This topology is used for high-bandwidth wireless backhaul services at maximum operating ranges using either line-of-sight (LOS) or no-line-of-sight (NLOS) signal propagation. It uses a backhaul as a high-capacity line from a remote site or network to a central site or network.

A point-to-multipoint topology is composed of a central BS supporting multiple SSs, providing network access from one location to many locations. It is commonly used for last-mile broadband access, private enterprise connectivity to remote offices, and long-range wireless backhaul services for multiple sites. Last-mile broadband access refers to communications technology that bridges the transmission distance between the broadband service provider and the customer premises equipment.

A mobile topology is similar to a cellular network because multiple BSs collaborate to provide seamless communications over a distributed network to both SSs and MSs.

83. Which of the following is a detective control in a local-area network (LAN) environment?

a. File backup

b. Contingency plan

c. Electronic surveillance

d. Locks and keys

83. c. Electronic surveillance is an example of detective controls. File backup is incorrect because it is an example of recovery controls. A contingency plan is incorrect because it is an example of recovery controls. Locks and keys are incorrect because they are examples of preventive controls.

84. Which of the following establishes accountability in a local-area network environment?

a. Network monitoring tools

b. Access logs

c. Lock and key systems

d. Card key systems

84. b. Access logs along with user IDs and passwords provide a reasonable amount of accountability in a local-area network (LAN) environment because user actions are recorded.