Final Exam - COSC 4325

The _______ is a United States government agency that regulates voice and data communication

FCC

A VLAN requires the computer manager to reconfigure the physical cables to the switch if a computer is moved from one port to another port on a switch .

False

A backbone network that connects many backbone networks spanning several buildings at a single location is often called an Internet backbone .

False

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

False

A disadvantage of a star architecture is that the failure of one circuit will disrupt the entire network .

False

A hardware device that operates at the application layer is a router .

False

A switch always broadcasts all the packets it receives to all the computers that are connected to the switch .

False

An OC - 1 circuit provides a data rate of 155 Mbps .

False

An access point plays the same role in a wireless network as a router does in a wired Ethernet network .

False

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

False

Cut - through switching has fewer errors than store and forward switching

False

Digital Subscriber Line is a family of multipoint technologies .

False

Fiber optic cable is thicker and heavier than unshielded twisted pair

False

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

False

One advantage of a routed backbone is that is requires little management.

False

The three latest versions of Ethernet run at speeds of 1Gbps , 10Gbps , and 50 Gbps .

False

A____________ type of BN has a star topology with a switch at its center resulting in all devices on the BN segment being part of the same IP network

Switched backbone

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

True

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

True

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

True

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

True

A switch can send and receive on all circuits simultaneously

True

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

True

Directional antennas signals are much stronger than omnidirectional antennas .

True

Hub - based Ethernet is a star physical topology and a bus logical topology .

True

In constructing Wide Area Networks , many organizations do not build their own long distance communication circuits .

True

Peering means that a tier 1 ISP does not charge another tier 1 ISP to transmit its messages .

True

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

True

The Network Interface Card ( NIC ) permits a computer to be physically connected to a network's cable .

True

The RFCs that form the basis for Internet standards are developed by the IETF and its working groups .

True

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

True

When a switch receives an Ethernet frame with a destination address that is not in its forwarding table , the switch will broadcast the frame out all of its other ports .

True

A _______ type of BN is a new type of LAN / BN architecture made possible by intelligent , high speed switches that assign computers to LAN segments via software rather than by hardware .

Virtual LAN

A ( n ) _____ is a radio transceiver that plays the same role as a hub or switch in a wired network and connects the WLAN to the wired network .

access point

Which of the following would be least effective in improving backbone performance ?

adding new keyboards to the client computers

A star topology is :

dependent upon the capacity of the central computer for its performance

A _____ is a group of centrally organized , related resources

domain

Which of the following is not a type of hardware device that can be used to interconnect networks ?

dumb terminals

The cheapest time to install network cabling is :

during the construction of the building

In a ring design WAN ,

failure in one circuit means that the network can most likely continue to function

A ( n ) _____ allows many users to share the same set of files on a common , shared disk drive .

file server

When a computer transmits at the same time because it cannot sense that another computer on the WLAN is currently transmitting is referred to as the :

hidden node problem

Of the following , which is not true about fiber optic cable ?

it has a very low capacity

Switches :

learn addresses by reading the source and destination addresses

The _____ is the connection from a home or business to the telephone company end office .

local loop

A logical bus topology

permits every message to be received by every computer on the bus , even when those messages are intended for other computers

Hubs :

usually incorporate repeaters or amplifiers

A _______ is a particular type of network that uses circuits that run over the Internet but that appears to the user to be a private network .

virtual private network

Fiber to the Home uses

wavelength division multiplexing

______ are dedicated digital circuits that are the most commonly used form of dedicated circuit services in North America today .

T-carrier services

Some of the new applications being developed for a high - speed Internet include

Tele - immersion

The most common cable modem standard is Data over Cable Service Interface Specification ( DOCSIS ) .

True

The most common type of DSL today is ADSL .

True

The primary advantage of a routed backbone is that it clearly segments each part of the network connected to the backbone because each segment has its own subnet addresses that can be managed separately

True

The step of understanding current traffic on a network provides a baseline against which future network requirements can be compared.

True

Tier 1 service providers connect together and exchange data at IXPs .

True

Time division multiplexing is more efficient that frequency division multiplexing because the guard-bands used in the frequency division multiplexing or not needed.

True

Today, many organizations design networks using the building - block approach.

True

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

True

WDM is a version of FDM used in fiber-optic cables.

True

Your typical web browsing scenario where a person using a web browser accesses a web page from a server on the Internet is a good example of a client - server application architecture.

True

A backbone network is:

a high speed central network that connects other networks in a distance spanning up to several miles.

A(n) is the way in which the functions of the application layer software are spread among the clients and servers in the network

application architecture

Errors on a network can occur:

because of noise on the line

The goal of the needs analysis step is to produce a _______ or a statement of the network elements necessary to meet the needs of the organization.

logical network design

Routers :

may also be called TCP / IP gateways

In a ring design WAN ,

messages can take a long time to travel from the sender to the receiver

The building block design approach is sometimes called:

narrow and deep

The ________ layer is responsible for routing of messages from the sender to the final destination.

network layer

Cross talk:

occurs when one circuit picks up signals in another

A ( n ) ______ is used to connect a fiber optic cable from the cable TV company side to a coaxial cable on the customer side .

optical electrical converter

A ____ is a user's connection into a packet switched service .

packet assembly / disassembly device

With contention:

computers wait until the circuit is free before they send data

Which of the following is not a property of a WAN:

connects a group of computers in a small geographic area such as room, floor, building or campus

A "thick client" architecture approach:

places all or almost all of the application logic on the client

________ is the presentation of information to the user and the acceptance of the user's commands.

presentation logic

The traditional network design approach does not work well for ______ networks.

rapidly growing

There are optional and required parts of an HTTP request. They are:

request line, request header, request body

There are required and optional parts of an HTTP response. They are:

response status, response header, response body

In the Internet model, the application layer corresponds to the layer(s) of the OSI model.

session, presentation, and application

Which of the following is not included in the key deliverable for the needs assessment stage of the building-block network design process , the set of logical network diagrams?

specific routers that have been chosen to implement the proposed network

We transmit 1000 bytes using Ethemet 802.3ac frame (see Figure 4-8a). Assume VLAN tag is not used and the control field is 1 byte long . Ignore Interframe spacing. What is the transmission efficiency? Round your answer to the nearest whole number percentage.

97

Give the answer in milliseconds. My office has a 1 Gbps connection to the Internet. How long does it take for my office to upload the 100 files in the previous question. (remember, 1 ms = one thousandth of a second)

160

How many bits are uploaded each day from my office? Give the answer in megabits. My office uploads 100 files each day where the average size of a file is 200,000 bytes (remember, 1 megabit = 1 million bits).

160

What is the bit rate of an analog circuit with a 20 MHz symbol rate using 256 - QAM ? Give the answer in Mbps.

160

Asynchronous transmission uses 7 bits for transmitting a character and 1 start bit and 1 parity bit for each character. What is the transmission efficiency in % (rounded to the nearest whole number) ?

78

A ______ is a device that permits a customer to connect to a digital T - carrier service

CSU / DSU

______ refers to the amount of data transmitted on a circuit.

Circuit loading

_____ are companies that build a data and telecommunications infrastructure from which other companies can lease services for WANs and MANS .

Common carriers

An intranet VPN connects different organizations over the Internet .

False

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

False

Data transmission errors are typically uniformly distributed in time

False

Digital transmission produces more errors than analog transmission.

False

Due to advances in high speed communication networks , the information lag, or the time it takes for information to be disseminated around the world, has been significantly lengthened.

False

Ethernet is a layer 3 protocol , which operates at the network layer .

False

Ethernet is an example of a network layer protocol.

False

Fiber optic cable carries signals in traditional electrical form.

False

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

False

Guided media refers to the type of media in which the message is broadcast through the air.

False

Host-based and client-based networks are similar in that the client computer performs most of the work.

False

In simplex transmission, the data flows in both directions at the same time

False

Layer - 3 switches switch messages based only on their data link layer address .

False

MPLS operate at layer 4 .

False

Needs analysis is the final step in the building block approach to network design.

False

Nonreturn to zero is a type of unipolar signaling

False

Only the sender of a data transmission needs to be concerned about the rules or protocols that govern how It communicates with the receiver

False

Propagation delay is negligible with satellite transmission.

False

Routers can only connect the same type of cable .

False

Symbol rate is the number of bits transmitted per second.

False

Technologies such as DSL and cable modem are called narrowband technologies .

False

The Internet is flat in structure .

False

The Internet is one large network .

False

The OSI model is currently the most widely implemented network model used to develop and build networks of any size, including the Internet itself.

False

The Simple Mail Transfer Protocol is the least commonly used e-mail standard

False

The application layer is the seventh layer of the Internet model and specifies the type of connection and the electrical signals that pass through it.

False

The campus backbone (or core layer) is the network architecture component responsible for providing end user access to the network.

False

The goals in the needs analysis step of network design are exactly the same when designing LANs vs. when designing WANS.

False

The standard protocol for communication between a Web browser and a Web server is the web protocol.

False

The traditional network design approach works very well for rapidly changing networks.

False

The turnpike effect results when a network is used at a much lower rate than was anticipated when it was designed.

False

Today, all network traffic is due to traffic from internal application systems.

False

Today, the most expensive part of the network is the hardware.

False

Using the POP standard for client to server e-mail communication, the e-mail messages remain on the server computer.

False

When obtaining the support of senior management for a proposed network it is important to use as much technical network jargon as possible.

False

With modem communications, the receiving modem converts the incoming digital signal from the telephone line into an analog signal that can be understood by the computer.

False

A T1 circuit provides a data rate of 1.544Mbps

True

A WAN with a ring topology can use full or half duplex circuits .

True

A car manufacturer may give access to certain portions of its network to some of its suppliers via the Internet. This is an example of an extranet.

True

A traditional network design approach follows a structured systems analysis and design process similar to that used in building applications.

True

A walkie-talkie is an example of half-duplex transmission.

True

ADSL uses FDM to create three channels over the one local loop circuit : one for voice , one for upstream data , and one for downstream data .

True

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

True

Attenuation refers to the loss of signal strength.

True

Coding schemes are groups of bits that translate into the "alphabet" of any given system.

True

Contention is commonly used with Ethernet local area networks

True

Cost assessment is used to look at the relative cost of technologies used in a network design.

True

Data communication standards enable each layer in the sending computer to communicate with its corresponding layer in the receiving computer.

True

Data compression can increase the throughput of a communication link.

True

Ethernet, a common LAN technology, uses Manchester encoding.

True

If a computer transmits a message containing "ABC" and the destination computer receives "abc" as the message, the message is corrupted

True

In a client-server network, the presentation logic is the responsibility of the client computer.

True

In full-duplex transmission, two stations can send and receive simultaneously.

True

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

True

The campus backbone is usually faster than the backbones used inside buildings.

True

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

True

The four general functions of any application program are: data storage, data access logic, application logic and presentation logic.

True

With odd parity and a 7 - bit ASCII code, 0110011, what is the parity bit ?

1

Consider case study IV (Alpha Corp on page 110). How many bits per second are generated by web accesses. Give your answer in whole number kbps.

267

Consider case study IV (Alpha Corp) on page 110. How many bits per second are generated by both email and web applications? Give your answer in whole number kbps.

270

Which of the following is not a step under the traditional network design approach?

An analyst takes the traffic on the current network and then multiplies that by a factor of 3.65 to come up with the estimate of the total traffic for the new network

Data communications and networking can be considered as a global area of study because:

Both A&B. A. new technologies and applications emerge from a variety of countries and spread around the world B. the technologies enable global communication

In a _____ more than one data bit is changed by the error-causing condition .

Burst error

Which of the following would not be a type of circuit that needs to be considered when planning for technology design capacity?

Ethernet

A(n) is a LAN that uses the same technologies as the Internet but is provided to invited users outside the organization who access it over the Internet.

Extranet

A "thin client" approach places most of the application logic on the client.

False

A VLAN network assigns computers to LAN segments by hardware .

False

A local area network (LAN) connects other LANs and backbone networks (BNS) located in different areas to each other and to wide area networks in a span from 3 to 30 miles.

False

Which department of Next Day Air Service Inc (the case study) has no automation whatsoever?

Fleet Maintenance Division

Which of the following is a term used to group together the physical and data link layers?

Hardware layers.

Which of the following new Internet efforts was started by 34 universities ?

Internet2

A(n) is a LAN that uses the same technologies as the Internet but is open to only those inside the organization

Intranet

Which of the following is not a key advantage of digital transmission?

It permits only low transmission rates.

Which of the following is not directly contributing to the dramatic increase in network traffic today?

Much of the video processing on computers can be off - loaded from the CPU onto high end video cards .

In the _______ step of the building-block process to network design , the network designer examines the available technologies and assesses which options will meet the users' needs.

Needs analysis

______ is an effective way to prevent Impulse noise cross talk, and Intermodulation noise.

Shielding wires

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.

True

Microwave transmissions require a line of sight between any two points.

True

Middleware is a software that can translate between software from different vendors.

True

Networks requirements can be divided into mandatory, desirable and wish-list requirements.

True

Scalability refers to the ability to increase or decrease the capacity of the computing infrastructure in response to changing capacity needs.

True

Which of the following is false about staff costs for a network?

When a variety of devices from different vendors are used in a network , it takes less time to perform network management activities

A local area network is:

a group of personal computers or terminals located in the same general area and connected by a common cable (communication circuit) so they can exchange information such as a set of rooms, a single building, or a set of well-connected buildings

With a client-based network, one fundamental problem is that

all data on the server must travel to the client for processing

With the two-tier client-server architecture, only the server is responsible for the ____ logic .

data access

Two fundamentally different types of data are:

digital and analog

When a signal is reflected back to the transmitting equipment, it is called a(n)

echo

The primary reason for networking standards is to:

ensure that hardware and software produced by different vendors can work together

Which of the following media is least susceptible to noise ?

fiber optic cable

Which of the following is not one of the three major steps used in the building-block process to network design?

implementation and maintenance

Media access control

is not very important in point to-point with full duplex configuration

How are the application architecture functions split up in a client-server network?

the presentation logic is on the client while the data storage and data access logic are on the server

One underlying problem with a host-based network is that:

the server can get overloaded since it must process all messages

Which layer of the OSI model is responsible for ensuring that all packets sent are received by the destination station by dealing with end-to-end issues?

transport

The _________ layer performs error checking which is redundant to some extent with the function of the _________ layer.

transport, data link

Mesh networks :

typically contain more circuits in the network than in star or ring networks

For access to DSL , ______ equipment is installed at the customer location .

customer premises

A T1 level of ADSL has a maximum downstream rate of about _______ Mbps .

1.5

Data traffic from the DSL customer premises is sent to a which is located at the local carrier's end office.

DSLAM

In general , tier 3 ISPs make money by charging

customers

Ethernet LAN was developed by

DEC , Xerox , and Intel

The _____ is responsible for technical management of IETF and the Internet standards process .

Internet Engineering Steering Committee

The _____ is a large open international community of network designers , operators , vendors , and researchers concerned with the evolution of the Internet architecture and smooth operation of the Internet .

Internet Engineering Task Force

At the top of the Internet structure are tier 1 ______ such as AT & T and Sprint .

Internet service providers

_______ is a common standard for use by layer 2 access VPNs for encapsulation .

L2TP

A subnetted or hierarchical backbone can also be called :

Routed backbone

_____ is the software that controls the network .

Network Operating System

Which of the following is not a basic LAN component ?

PAD

Which of the following is not a benefit of packet switched services ?

The data transmission rates tend to be lower than dial - up or dedicated circuits .

Which of the following is true regarding switched backbones ?

They place all network devices for one part of the building physically in the same room , often in a rack of equipment

Which of the following is not true about backbone networks ?

They tend to use lower speed circuits than LANS .

Which of the following is not a technology layer that is considered when designing backbone networks ?

decentralized layer

Technologies that provide higher - speed communications than traditional modems e.g. , DSL are known as technologies .

broadband

Which of the following is not a basic architecture for dedicated circuit networks ?

bus

A ( n ) ______ contains a series of cable modems / multiplexers and converts the data from cable modem protocols into protocols needed for Internet traffic , before passing them to a router connected to an ISP POP .

cable modem termination system

A ( n ) _____ is not a common type of dedicated server

collision server

Routers :

connect different IP networks or subnetworks

A star architecture :

connects all computers to one central computer that routes messages to the appropriate computer

A ------ geometric layout connects all computers in a closed loop , with each computer linked to the next usually with a series of point - to - point dedicated circuits

ring design

Which of the following is not true about switched backbones ?

there are many more networking devices in a switched backbone network compared to the number of LANS attaching to it