Archive for March 2018

Data Communication & Networking - True - False - 7

As the number of ISPs has grown, a new form of network access point called a metropolitan area exchange has emerged.

Answer: True

 Common carriers include the RBOCs, IXCs, and Cable TV companies.

Answer: True

 Common carriers sell or lease communication services and facilities to the public.

Answer: True

 Circuit switched networks run over the public switched telephone networks operated by the common carriers.

Answer: True

 Cloud (as in cloud architecture) means that the design for the common carrier's network comes from satellite networks above the clouds.

Answer: False

 A dedicated circuit is usually not available late at nights or on weekends.

Answer: False

 Full mesh networks are inexpensive.

Answer: False

 Full mesh design networks are more common than partial mesh design networks.

Answer: False

 Datagrams are connection-oriented.

Answer: False

 Connectionless routing sets up a TCP connection, or virtual circuit between a sender and receiver.

Answer: False

 Virtual private networks permit users to create permanent virtual circuits, or tunnels, through the Internet.

Answer: True

 National Internet service providers connect together and exchange data at Network Access Points.

Answer: True

 Network access points were originally designed to connect only local ISPs.

Answer: False

 A point of presence is the place at which the ISP provides services to its customers.

Answer: True

 Peering means that a national ISP does not charge another national ISP to transmit its messages.

Answer: True

 Digital Subscriber Line is a family of multipoint technologies.

Answer: False

 The dominant standard for a cable modem is Data over Cable System Interface Specification.

Answer: True

 Internet 2 is the common name for the Abilene network.

Answer: True

 Each of the networks in Internet 2 has a set of access points called terapops.

Answer: False

 Security on a network not only means being able to prevent a hacker from breaking into your computer but also includes being able to recover from temporary service problems or from natural disasters.

Answer: True

 The rise of the Internet has increased significantly the potential vulnerability of an organization's assets.

Answer: True

 Confidentiality is not a threat to business continuity.

Answer: False

 Intrusion refers to confidentiality and integrity of data.

Answer: True

 A control spreadsheet lists threats to the network across the top of the spreadsheet and lists the network assets down the side of the sheet.

Answer: True

 A threat to the data communications network is any potential adverse occurrence that can do harm, interrupt the systems using the network, or cause a monetary loss to the organization.

Answer: True

 Companies have learned that threats from hacking from its own employees occur about as often as by outsiders.

Answer: True

 A NAT proxy server uses an address table to translate private IP addresses used inside the organization into proxy data link layer addressed used on the Internet.

Answer: True

Data Communication & Networking - True - False - 6

A hardware device that is not included in a network profile cannot be accessed by another computer on the network.

Answer: True

 User profile refers to what resources on each server are available on the network for use by other computers and which devices or people are allowed access on the network.

Answer: True

 Traditional Ethernet is also known as shared Ethernet.

Answer: True

 Wireless LANs use Carrier Sense Multiple Access with Collision Detection (CSMA/CD) for medic access control.

Answer: False

 A collision on a bus circuit means that two computers on that circuit have transmitted at the same time.

Answer: True

 Traditional Ethernet is also known as shared Ethernet.

Answer: True

 Traditional Ethernet and switched Ethernet account for almost all LANs installed today.

Answer: True

 Wireless LANs serve the same purpose as wired LANs.

Answer: True

 Wireless LANs are never connected to a wire network.

Answer: False

 The data link layer protocols used by wireless LANs are similar to the ones used on Ethernet LANs.

Answer: True


 Wireless LANs do not share the bandwidth capacity of the wireless network.

Answer: False

 An access point (AP) is required to connect a WLAN to a wired network.

Answer: True

 A backbone network is a high-speed network that connects many networks

Answer: True

 Backbone networks typically use lower speed circuits to interconnect a series of LANs and provide connections to other backbone networks.

Answer: False

 One basic component of a backbone network is the hardware device that connects other networks to the backbone.

Answer: True

 Switches, routers, and gateways are devices that can connect networks to the BN.

Answer: True

 The cable to connect BNs is usually twisted pair.

Answer: False

 Routers can only connect the same type of cable.

Answer: False

 Routers use network layer address to forward packets between network segments.

Answer: True

 Routers operate at the application layer.

Answer: False

 Routers connect two or more network segments that use the same or different data link protocols, but the same network protocol.

 Answer: True

One advantage of a router is that it can choose the "best" route between networks when there is a choice.

 Answer: True

 Gateways are simpler than routers.

Answer: False

 The terms for hardware devices, such as routers and gateways, are interchangeable among vendors.

Answer: False

 Gateways connect two or more networks that use the same or different data link and the same or different network protocols.

Answer: True

 One of the least common uses of gateways is to enable LANs that use TCP/IP and Ethernet to communicate with mainframes that use other protocols.

Answer: False

 A room that contains a rack of equipment for a rack-based collapsed backbone is also called the main distribution facility (MDF) or central distribution facility (CDF).

Answer: True

Data Communication & Networking - True - False - 5

Translating an application layer address to a network layer address and finally to a data link layer address is called address resolution.

Answer: True

 Part of the function of address resolution is translating the application layer address of the destination into a network layer address.

Answer: True

 An Address Resolution Protocol message is broadcast to all computers in a subnet to find the data link layer address.

Answer: True

 Subnet masks tell computers what part of an IP address is to be used to determine whether a destination is in the same subnet or in a different subnet.

Answer: True

 The most common standard for dynamic addressing for TCP/IP networks is Dynamic Host Control Protocol.

Answer: True

 Connectionless routing sets up a TCP connection, or virtual circuit between a sender and receiver.

Answer: False

 Routing is the process of determining the path or route through the network that a particular message will follow from the sender to the recipient.

Answer: True

 There are four fundamental approaches to routing: centralized, static routing, dynamic routing, and monitor routing.

Answer: False

 Resource sharing refers to having users access the same data files, exchange information via e-mail, or use the Internet.

Answer: False

 On a network, it is always legal to purchase one copy of software, such as a word processing package, that multiple users use simultaneously.

Answer: False

 LAN metering software can be used to prohibit using more copies of a package than there are installed licenses.

Answer: True

 Software Publishers Association has embarked upon an aggressive software audit program to check the number of illegal software copies on LANs.

Answer: True

 LANs can be categorized as either dedicated (with a dedicated server) or peer-to-peer (without a dedicated server).

Answer: True

 Peer-to-peer networks have computers that are permanently assigned as network servers.

Answer: False

 As discussed in this textbook, three layers of a network model are the components required for a typical network, including local area networks.

Answer: False

 The Network Interface Card (NIC) permits a computer to be physically connected to a network's cable, which provides the network layer connection among the computers in the network.

Answer: False

A Network Operating System (NOS), such as Linux or Windows Server 2008, must be used in addition to the 'normal' operating system, such as Windows, on a server in a dedicated server LAN.

Answer: False

 One of the most important functions of Network Operating System (NOS) is a directory service.

Answer: True

 The NOS software for the server computer provides the physical, data link, and network layer functions.

Answer: False

Data Communication & Networking - True - False - 4

Contention is commonly used with Ethernet local area networks.

Answer: True

 Traditional Ethernet and switched Ethernet account for almost all LANs installed today.

Answer: True

 The Ethernet standard was developed first by the IEEE.

Answer: False

 At the transport layer in the Internet model, TCP is responsible for breaking large files received from the application layer into smaller packets and opening a connection to a server for transferring the packets.

Answer: True

 The transport layer routes messages thought the network selecting the best path from the source to the destination station.

Answer: False

 The transport layer process running on the destination computer, reassembles the fragmented application message before passing it up to the application layer.

Answer: True

 Because there is a limit on the length of a frame that the data link layer can transmit from node to node, the transport layer breaks up the message from the application layer into several smaller packets.

Answer: True

 The network layer is responsible for routing messages from the source computer to the destination computer.

Answer: True

 Ethernet is an example of a network layer protocol.

Answer: False

 The data link layer accepts messages from the network layer and controls the hardware that transmits them.

Answer: True

 The network layer sits directly between the application layer and the data link layer in the Internet five-layer network model.

Answer: False

TCP/IP is a data link protocol that is used on the Internet.

Answer: False

 The network layer is responsible for end-to-end delivery of the message.

Answer: False

 TCP is the network layer protocol used on the Internet today.

Answer: False

 The TCP portion of TCP/IP performs linking to the application layer.

Answer: True

 IP is responsible for error-free delivery of packets on a TCP/IP network.

Answer: False

 The latest version of IP is IPv7, which increases the address space from 128 bits to 256 bits.

Answer: False

TCP includes a sequence number so that the packets can be reassembled at the destination in the correct order.

Answer: True

 TCP/IP operates only as connection-oriented.

Answer: False

 Quality of Service routing is a special type of connection-oriented routing in which different connections are assigned different priorities.

Answer: True

 The data link layer address is generally encoded in a network card by the card's manufacturer.

Answer: True

 IPv4 addresses offer unlimited opportunity for expansion and growth on the Internet.

Answer: False

 Domain Name Servers provide the equivalent of directory assistance for application layer addresses.

Answer: True

Data Communication & Networking - True - False - 3

Eliminating jitter to generate a pure carrier signal in an analog circuit is impossible.

Answer: True

 The distance between repeaters or amplifiers on a telephone circuit is determined by the amount of power gained per unit length of the transmission.

Answer: False

 When we amplify the signal on an analog circuit, we also amplify any noise that is present on the circuit.

Answer: True

 In an odd parity-checking scheme, the parity bit is set to make the total number of ones in the byte (including the parity bit) an even number.

Answer: False

 Parity checking can only detect an error when an even number of bits are switched.

Answer: False

 The simplest method for error correction is retransmission.

Answer: True

 One type of forward error correction is the Hamming code.

Answer: True

 Forward error correction is commonly used in satellite transmission.

Answer: True

 Point-to-point Protocol is a byte-count-oriented protocol.

Answer: True

Data Communication & Networking - True - False - 2

Token passing is a term that refers to hub polling, in which one computer starts a poll and passes it to the next computer on a multipoint circuit.

Answer: True

 With contention, a computer does not have to wait before it can transmit. A computer can transmit at anytime.

Answer: False

 Contention is commonly used with Ethernet local area networks.

Answer: True

 Undesirable stray electrical voltage can cause data communication errors.

Answer: True

 Gaussian noise is a special type of attenuation.

Answer: False

 Impulse noise is caused by the thermal agitation of electrons.

Answer: False

 Crosstalk occurs when the signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel.

Answer: True

 Attenuation refers to the loss of signal strength.

Answer: True

 When the signals from two circuits combine to form a new signal that falls into a frequency band reserved for another signal, this is called, intermodulation noise.

Answer: True

Data Communication & Networking - True - False - 1

Frequency modulation refers to the changing of the height of the sound wave.

Answer: False

 Baud rate is the number of bits transmitted per second.

Answer: False

 Multiplexing increases the cost of provisioning network circuits.

Answer: False

 Media access controls refer to the need to control when computers transmit.

Answer: True

 Controlled access MAC approaches work better in a large network with high usage.

Answer: True

 A collision on a bus circuit means that two computers on that circuit have transmitted at the same time.

Answer: True

 Wireless LANs use Carrier Sense Multiple Access with Collision Detection (CSMA/CD) for medic access control.

Answer: False

 Polling is the process of permitting all clients to transmit or receive at any time.

Answer: False

 Most computer networks managed by a host mainframe computer use contention media access control.

Answer: False

 With roll-call polling, a server polls clients in a consecutive, pre-arranged priority list.

Answer: True

Threat of intrusion comes from ____________.

Threat of intrusion comes from ____________.




a. the government
b. crackers
c. outside of the organization
d. both inside and outside of the organization
e. inside of the organization



Answer: D

In recent years, management's concern about the adequacy of current control and security mechanisms used in a data communications environment has:

In recent years, management's concern about the adequacy of current control and security mechanisms used in a data communications environment has: 




a. decreased because the new sophisticated technology is far more secure than the old manual methods
b. remained the same because management was always deeply interest in control and security
c. decreased because of the change in moral and ethical codes in the U.S. to a kinder and gentler society
d. increased because this commitment to data communications has changed the potential vulnerability of the organization's assets
e. remained the same because there are very few threats to data communications



Answer: D

Internet 2 is also known as:

Internet 2 is also known as:




a. CA*Net3
b. IETF
c. Next Generation Internet
d. the Abilene network
e. passive optical networking



Answer: D

Digital Subscriber Line:

Digital Subscriber Line:




a. is a fairly recent approach to provide higher data transmission rates across traditional voice circuits in the local loop
b. combines analog transmission and frequency division multiplexing
c. involves the use of a customer premises equipment (CPE)
d. uses a combination of amplitude and phase modulation
e. all of the above



Answer: E

National ISPs connect together and exchange data at ___________.

National ISPs connect together and exchange data at ___________.




a. Network Access Points
b. cable modem termination system endpoints
c. distribution hubs
d. the Internet engineering task force headquarters
e. the Internet Society network center



Answer: A

Which of the following is not a type of VPN?

Which of the following is not a type of VPN?




a. intranet VPN
b. extranet VPN
c. access VPN
d. T-1 VPN
e. a VPN that enables employees to access an organization's network from a remote location



Answer: D

Mesh networks:

Mesh networks: 




a. usually provide relatively long routes through the network (compared to ring networks)
b. require more processing by each computer in the network than in star or ring networks
c. do not use decentralized routing
d. do not have much capacity wasted by network status information
e. do not have many possible routes through the network to prevent one circuit from becoming overloaded



Answer: B

In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.

In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.



Answer: True

In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.

In the three-tier architecture, the software on the client computer is responsible for the presentation logic, an application server is responsible for the application logic and a separate database server is responsible for the data access logic and data storage.



Answer: True
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