CPS Flashcards
1
Q
The sender and receiver end points, in a communications system, are referred to as
A
host
2
Q
host
A
refers to as the sender and receiver end points, in a communications system
3
Q
Since data communication is predominantly serial, we usually describe the data as a
A
byte stream
4
Q
byte stream
A
How we usually describe the data since data communication is predominantly serial.
5
Q
To solve the related problems of channel availability and maximum utilization, there must be a way to break long messages into smaller units. These units are called
A
packets
6
Q
packets
A
These units are used to solve the related problems of channel availability and maximum utilization, a way to break long messages into smaller units.
7
Q
A _________is equivalent to an envelope containing pages of data
A
packet
8
Q
packet
A
is equivalent to an envelope containing pages of data
9
Q
packet
A
is equivalent to an envelope containing pages of data
10
Q
A direct USB connection between a smartphone and a personal computer is an example of
A
point-to-point connection
11
Q
Example of a point-to-point connection
A
A direct USB connection between a smartphone and a personal computer.
12
Q
The typical communication channel is actually divided into segments; connections along the segments are called
A
links
13
Q
links
A
Connections along the segments on a typical communication channel.
14
Q
The rate of speed with which data can be moved successfully through the channel is usually measured as a
A
bit rate. (bandwidth)
15
Q
bit rate. (bandwidth)
A
The measurement of the rate of speed with which data can be moved successfully through the channel.
16
Q
Which is not an example of an unguided medium?
A
USB connection from computer to smartphone
17
Q
USB connection from computer to smartphone is not an example of what?
A
unguided medium
18
Q
Some channel characteristics are determined innately by the medium. For example, unguided messaging must be carried by an analog signal known as a
A
carrier signal.
19
Q
A carrier signal
A
is an analog signal where some channel characteristics are determined innately by the medium. For example, unguided messaging must be carried by an analog signal known as a carrier signal
20
Q
Channels that carry messages in only one direction are known as
A
simplex channels.
21
Q
simplex channels.
A
Channels that carry messages in only one direction
22
Q
Channels that carry messages in both directions, but only one direction at a time, are called
A
half-duplex channels
23
Q
half-duplex channels
A
Channels that carry messages in both directions, but only one direction at a time
24
Q
Channels that carry signals simultaneously in both directions are called
A
full-duplex channels.
25
full-duplex channels
Channels that carry signals simultaneously in both directions
26
A relatively small number of standard protocols, consisting primarily of the _____________ protocol suites, satisfy nearly all of the communication requirements for modern data communication networks.
TCP/IP and Ethernet
27
TCP/IP and Ethernet
A relatively small number of standard protocols, consisting primarily of the _____________ protocol suites, satisfy nearly all of the communication requirements for modern data communication networks.
28
In a __________ topology each computer node gets every message, but processes only those addressed to that node. There is no central hub in this topology.
bus
29
Which of the following topologies is used primarily for local area networks; all nodes are connected point-to-point to a central device that uses switching technology to connect pairs of nodes together?
star
30
star
used primarily for local area networks; all nodes are connected point-to-point to a central device that uses switching technology to connect pairs of nodes together
31
bus
each computer node gets every message, but processes only those addressed to that node. There is no central hub in this topology.
32
Which of the following topologies consists of point-to-point connections from each node on the network to the next node; the last node on the network is connected back to the first and there is no central hub?
ring
33
ring
consists of point-to-point connections from each node on the network to the next node; the last node on the network is connected back to the first and there is no central hub
34
Which type of topology describes the actual layout of the wiring for the network?
physical
35
physical
describes the actual layout of the wiring for the network
36
Which type of topology defines the operational relationship between the various network components?
logical
37
logical
defines the operational relationship between the various network components
38
Which type of network connects computers and other supporting devices over a relatively small localized area, typically a room, the floor of a building, a building, or multiple buildings within close range of each other?
LAN
39
LAN
network that connects computers and other supporting devices over a relatively small localized area, typically a room, the floor of a building, a building, or multiple buildings within close range of each other?
40
The most familiar, and often most practical and useful, way to categorize networks is by their
geographical range of service
41
geographical range of service
The most familiar, and often most practical and useful, way to categorize networks
42
) In a(n) ___________ hub, all of the connections at the hub are simply tied together inside the hub and the hub performs no operation or modification of the signals as they arrive at the hub.
passive
43
passive hub
In a(n) ___________ hub, all of the connections at the hub are simply tied together inside the hub and the hub performs no operation or modification of the signals as they arrive at the hub.
44
Which Ethernet technology uses radio-based signals to communicate to devices connected on the local area network?
Wi-Fi
45
Wi-Fi
Ethernet technology uses radio-based signals to communicate to devices connected on the local area network
46
Which Ethernet type is based logically on a star topology and when one node on the network wishes to communicate with another node, the switch sets up a direct connection between the two?
Switched Ethernet
47
Switched Ethernet
Ethernet type is based logically on a star topology and when one node on the network wishes to communicate with another node, the switch sets up a direct connection between the two
48
Each wireless unit is connected by radio to a base station _____________ that is somewhat equivalent to a hub.
access point
49
access point
Each wireless unit is connected by radio to a base station _____________ that is somewhat equivalent to a hub.
50
Which type of network is used to interconnect local area networks? The primary motivation for this type of network is to improve overall performance of a larger network by creating separate local area networks for groups of users who communicate primarily with each other.
backbone networks
51
backbone networks
network is used to interconnect local area networks? The primary motivation for this type of network is to improve overall performance of a larger network by creating separate local area networks for groups of users who communicate primarily with each other.
52
In a wireless network where the access points are connected by radio, the mesh points operate at the ___________ and are essentially invisible to the upper layers of the network.
media access control layer (layer 2)
53
media access control layer (layer 2)
In a wireless network where the access points are connected by radio, the mesh points operate at the ___________ and are essentially invisible to the upper layers of the network.
54
Operation of a metropolitan area network (MAN) generally requires
right of way access.
55
right of way access.
Operation of a metropolitan area network (MAN) generally requires
56
An access router that is located between the public Internet and the internal LAN is called (a)n
edge router.
57
edge router.
An access router that is located between the public Internet and the internal LAN is called (a)n
58
Which type of network is designed to facilitate communications between users and applications over large distances—between the various corporate offices of an international organization that are located in cities all over the world, for example.
WAN
59
WAN
Which type of network is designed to facilitate communications between users and applications over large distances—between the various corporate offices of an international organization that are located in cities all over the world, for example.
60
Which type of network has ranges of only thirty feet or less, but is sufficient for an individual to interconnect his personal computing devices?
PAN
61
PAN
Which type of network has ranges of only thirty feet or less, but is sufficient for an individual to interconnect his personal computing devices?
62
How might a LAN be designed in a business setting to minimize extraneous traffic where possible?
Create separate LANs for each department.
63
Create separate LANs for each department.
How might a LAN be designed in a business setting to minimize extraneous traffic where possible?
64
What makes virtual circuits more efficient in the use of transmission resources than traditional circuit switching?
Links and intermediate nodes are shared with other connections.
65
Links and intermediate nodes are shared with other connections.
What makes virtual circuits more efficient in the use of transmission resources than traditional circuit switching?
66
Which of the following is not true about datagram switching?
TCP/IP rarely uses datagram switching.
67
TCP/IP rarely uses datagram switching.
Which of the following is not true about datagram switching?
68
How do routers and gateways differ?
Routers connect similar networks together; gateways interconnect dissimilar networks.
69
Which of the following is not a major organization that participates in the creation of standards for data communications, networks, and internetworks?
Association for Computing Machinery (ACM)
70
Association for Computing Machinery (ACM)
Which of the following is not a major organization that participates in the creation of standards for data communications, networks, and internetworks?
71
How is the word "data" used in this chapter?
"Note that we use the word “data” in the broadest possible sense of the word, to include programs, as well as traditional data, e-mail, music, streaming video, instant messaging, cell phone texts, network-based telephony—indeed, anything that can be communicated with bits and bytes."
72
What types of interpersonal communication do networks enable?
"…texting, e-mail, instant messaging (IM), social networking, voice-over-IP Internet telephony, Internet multiplayer games, collaborative work tools, real-time video conferencing, web surfing…. " examples of the application layer
73
What are the three essential ingredients for data communication?
"first, the data being passed between sender and receiver represents messages that are to be shared among the parties to the communications, second, there must be a communication channel that can capably and reliably transport the messages, and third, there must exist protocols that establish accurate and appropriate meaning to the messages that are understood by both senders and receivers. The second example also raises the issues of connectivity methods and addressing."
74
Why is it important to limit the length of a message sent over a communications channel?
Without some form of control, very large messages (i.e., streaming video download) could tie up a communication channel indefinitely. This would prohibit the use of the channel for other messages sharing the channel. It is easily broken up and causing errors.
75
Give a general description of the types of information contained in a "packet."
Answers will vary. But generally, as described in subsection Packets under section 12.3, a packet consists of the message content enclosed with information about receiver and sender address, error-checking, and information about the enclosed content (i.e. length of the content message), etc. Also, a packet number if the packet was part of a larger message and needs to be reassembled.
76
Give a general description of the types of information contained in a "packet."
Answers will vary. But generally, as described in subsection Packets under section 12.3, a packet consists of the message content enclosed with information about receiver and sender address, error-checking, and information about the enclosed content (i.e. length of the content message), etc. Also, a packet number if the packet was part of a larger message and needs to be reassembled.
77
What are the important advantages of using packets in data communications? There are at least 6 advantages listed in the class, here are 3 to get started:
1) Packets simplify operations and increase communication efficiency. Packets reduce communication overhead by making it possible to transmit a large block of data while requiring only a single block of overhead information to identify the destination and meaning of the enclosed data.
2) Packets also present an opportunity to check and fix errors in individual packets as the message is being sent, rather than having to resend the entire message.
3) A packet represents a reasonable unit for the routing of data. This factor is particularly important in wide area networks, where a packet of data may be passed through many different networks and communication channels before it reaches its destination.
78
What are "links" in a communications channel?
"the communication channel is actually divided into segments, called links, with intermediate nodes between the links that forward packets from one link to the next."
79
Each individual link channel is characterized by a number of different properties. Some of them are a) type of medium, b) signaling method, c) directionality of signals, d) nature of the interfaces with the end nodes and with other links. What are the other properties?
e) link bandwidth
f) restrictions on the length of the channel
g) the time delay between the time the channel receives data from its incoming node and the time it releases the data to its outgoing node
h) the number of connections sharing the channel
i) the noise characteristics of the channel
j) guided or unguided
k) the electrical or optical properties of the channel
80
How many connections are required for 30 nodes to be connected in a full mesh topology?
The formula is
Number of connections = (Nodes)(Nodes-1)/2
30*29/2 = 435
81
With a bus topology, each node is tapped into the bus. To communicate, a sending node “broadcasts” a message that travels along the bus. How does the recipient node know the message is intended for that node?
Since every node receives the message, each node must compare its address to the message destination address. If the destination address is different, the message is ignored. If the destination address matches, the node processes the message.
82
What is the difference between physical and logical topology?
"…it is important to understand that there is a difference between physical topology and logical topology. Physical topology describes the actual layout of the wiring for the network. Logical topology defines the operational relationship between the various network components."
83
What is the difference between a "passive" and "active" hub?
"The word “passive” means that the hub performs no operation or modification of the signals as they arrive at the hub. In contrast, an active hub recreates the arriving signals."
“Hop”
84
How do backbone networks improve the efficiency of very large LANs?
Backbone networks interconnect separate LANs. Separate LANs can be provided to localized groups of users, such as an HR department, library, dormitory areas, dining halls etc. This isolates the traffic within areas of common usage. A backbone network would provide the interconnections between all of these LANs, thus making it possible to extend the overall range of the combined networks well beyond that of a single LAN.
85
What is an intranet? And what are the limitations due to geographic considerations?
"An intranet is an organizational network where the user interfaces and applications are based primarily on Web services. Its use is restricted to authorized users within the organization. Some network practitioners refer to it as a 'private Internet'."
86
The Internet is just a gigantic network of interconnected networks, connecting a high percentage of all the computers in the world. In practice, though, the number of intermediate nodes, measured as hops between nodes, would make this scheme impractical. How is the number of "hops" reduced on the Internet?
Fast connections between distant points are used to reduce the time it takes to traverse long distances, to reduce the number of hops to just a few, and to reduce the traffic on the local connections.
87
Please draw TCP/IP model and explain the main function of each layer.
4. Application : Represents the data to the user plus encoding and dialog control. 3. Transport: supports communication between diverse devices across diverse networks. 2. Internet: Determines the best path through the network 1. Network: Controls the hardware devices and media that make up the network.
88
Please list at least 3 jobs of a system administrator.
install, upgrade and monitor software and hardware. data backup and recovery. maintain the essentials such as operating systems, business applications, security tools, web-servers, email, PCs, local and wide area networking both hardware and software and mid-range server hardware.
89
What is an operating system Kernel?
the kernel is a computer program that manages I/O (input/output) requests from software, and translates them into data processing instructions for the central processing unit and other electronic components of a computer.
90
Please draw a diagram to describe Bootstrapping procedure with a loader.
1. start, roll (loader)
2. Locate OS kernel (HD)
3. Load Kernel into RAM memory
4. Transfer Control
91
Please draw the three design patterns for operating systems and their pros and cons.
Table , recursive and multiple
