Which of the following is a telecommunication service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between end-points in a wide area network (WAN)?
Correct Answer: B
Frame relay is a telecommunication service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between end-points in a wide area network (WAN). Frame relay puts data in a variable-size unit called a frame. It checks for lesser errors as compared to other traditional forms of packet switching and hence speeds up data transmission. When an error is detected in a frame, it is simply dropped. The end points are responsible for detecting and retransmitting dropped frames. Answer option C is incorrect. Integrated Services Digital Network (ISDN) is a digital telephone/telecommunication network that carries voice, data, and video over an existing telephone network infrastructure. It requires an ISDN modem at both the ends of a transmission. ISDN is designed to provide a single interface for hooking up a telephone, fax machine, computer, etc.ISDN has two levels of service, i.e., Basic Rate Interface (BRI) and Primary Rate Interface (PRI). Answer option A is incorrect. The Point-to-Point Protocol, or PPP, is a data link protocol commonly used to establish a direct connection between two networking nodes. It can provide connection authentication, transmission encryption privacy, and compression. PPP is commonly used as a data link layer protocol for connection over synchronous and asynchronous circuits, where it has largely superseded the older, non-standard Serial Line Internet Protocol (SLIP) and telephone company mandated standards (such as Link Access Protocol, Balanced (LAPB) in the X.25 protocol suite). PPP was designed to work with numerous network layer protocols, including Internet Protocol (IP), Novell's Internetwork Packet Exchange (IPX), NBF, and AppleTalk. Answer option D is incorrect. The X.25 protocol, adopted as a standard by the Consultative Committee for International Telegraph and Telephone (CCITT), is a commonly-used network protocol. The X.25 protocol allows computers on different public networks (such as CompuServe, Tymnet, or a TCP/IP network) to communicate through an intermediary computer at the network layer level. X.25's protocols correspond closely to the data-link and physical-layer protocols defined in the Open Systems Interconnection (OSI) communication model.
Question 57
Jason has set a firewall policy that allows only a specific list of network services and denies everything else. This strategy is known as a ____________.
Correct Answer: D
Question 58
You are responsible for network functions and logical security throughout the corporation. Your company has over 250 servers running Windows Server 2012, 5000 workstations running Windows 10, and 200 mobile users working from laptops on Windows 8. Last week 10 of your company's laptops were stolen from a salesman, while at a conference in Barcelona. These laptops contained proprietary company information. While doing a damage assessment, a news story leaks about a blog post containing information about the stolen laptops and the sensitive information. What built-in Windows feature could you have implemented to protect the sensitive information on these laptops?
Correct Answer: C
Question 59
Which of the following IEEE standards is an example of a DQDB access method?
Correct Answer: B
Question 60
Which of the following TCP/IP state transitions represents no connection state at all?
