Which of the following is a sophisticated computer based switch that can be thought of as essentially a small in-house phone company for the organization?
A. Private Branch Exchange
B. Virtual Local Area Network
C. Voice over IP
D. Dial-up connection
A Private Branch Exchange(PBX) is a sophisticated computer based switch that can be thought of as essentially a small in-house phone company for the organization that operates it. Protection of PBX is thus a height priority. Failure to secure PBX can result in exposing the organization to toll fraud, theft of proprietary or confidential information, loss of revenue or legal entanglements.
PBX environment involves many security risks, presented by people both internal and external to an organization. The threat of the PBX telephone system are many, depending on the goals of these attackers, and include:
Theft of service – Toll fraud, probably the most common of motives for attacker.
Disclosure of Information -Data disclosed without authorization, either by deliberate actionably accident. Examples includes eavesdropping on conversation and unauthorized access to routing and address data.
Data Modification -Data altered in some meaningful way by recording, deleting or modifying it. For example, an intruder may change billing information or modify system table to gain additional services.
Unauthorized access – Actions that permit an unauthorized user to gain access to system resources or privileges.
Denial of service -Actions that prevent the system from functioning in accordance with its intended purpose. A piece of equipment or entity may be rendered inoperable or forced to operate in a degraded state; operations that depend on timeliness may be delayed.
Traffic Analysis – A form of passive attack in which an intruder observes information about calls and make inferences, e.g. from the source and destination number or frequency and length of messages. For example, an intruder observes a high volume of calls between a companys legal department and patent office, and conclude that a patent is being filed.
The following were incorrect answers:
Virtual Local Area Network – A virtual local area network (VLAN) is a logical group of workstations, servers and network devices that appear to be on the same LAN despite their geographical distribution. A VLAN allows a network of computers and users to communicate in a simulated environment as if they exist in a single LAN and are sharing a single broadcast and multicast domain. VLANs are implemented to achieve scalability, security and ease of network management and can quickly adapt to change in network requirements and relocation of workstations and server nodes.
Voice over IP – VoIP is a technology where voice traffic is carried on top of existing data infrastructure. Sounds are digitalized into IP packets and transferred through the network layer before being decode back into the original voice.
Dial-up connection – Dial-up refers to an Internet connection that is established using a modem. The modem connects the computer to standard phone lines, which serve as the data transfer medium. When a user initiates a dial-up connection, the modem dials a phone number of an Internet Service Provider (ISP) that is designated to receive dial-up calls. The ISP then establishes the connection, which usually takes about ten seconds and is accompanied by several beeping an buzzing sounds.
The following reference(s) were/was used to create this question:
CISA review manual 2014 Page number356