0. Introduction - Tests Flashcards
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
A local area network (LAN) is a group of computers located in the same general area. A LAN covers a clearly defined small area, such as one floor or work area, a single building, or a group of buildings.
Most LANs are connected to a backbone network (BN), a larger, central network connecting several LANs, other BNs, MANs, and WANs. BNs typically span from hundreds of feet to several miles and provide very high-speed data transmission, commonly 100–1,000 Mbps
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
The transport layer deals with end-to-end issues, such as procedures for entering and departing from the network.
It establishes, maintains, and terminates logical connections for the transfer of data between the original sender and the final destination of the message.
It is responsible for breaking a large data transmission into smaller packets (if needed), ensuring that all the packets have been received, eliminating duplicate packets, and performing flow control to ensure that no computer is overwhelmed by the number of messages it receives.
Although error control is performed by the data link layer, the transport layer can also perform error checking.
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 network model that dominates current hardware and software is a more simple five-layer Internet model. Unlike the OSI model that was developed by formal committees, the Internet model evolved from the work of thousands of people who developed pieces of the Internet.
The OSI model is a formal standard that is documented in one standard, but the Internet model has never been formally defined; it has to be interpreted from a number of standards. The two models have very much in common. Simply put, the Internet model collapses the top three OSI layers into one layer. Because it is clear that the Internet has won the “war,” we use the five-layer Internet model for the rest of this book
An intranet is a LAN that uses Internet technologies and is publicly available to people outside of the organization.
False
An intranet is a LAN that uses the same technologies as the Internet (e.g., Web servers, Java, HTML [Hypertext Markup Language]) but is open to only those inside the organization. For example, although some pages on a Web server may be open to the public and accessible by anyone on the Internet, some pages may be on an intranet and therefore hidden from those who connect to the Web server from the Internet at large.
Sometimes, an intranet is provided by a completely separate Web server hidden from the Internet. The intranet for the Information Systems Department at Indiana University, for example, provides information on faculty expense budgets, class scheduling for future semesters (e.g., room, instructor), and discussion forums.
In the OSI model, the application layer provides a set of utilities for applications and is the end user’s access to the network.
True
The application layer is the end user’s access to the network. The primary purpose is to provide a set of utilities for application programs.
Each user program determines the set of messages and any action it might take on receipt of a message. Other network-specific applications at this layer include network monitoring and network management.
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
An extranet is similar to an intranet in that it, too, uses the same technologies as the Internet but instead is provided to invited users outside the organization who access it over the Internet. It can provide access to information services, inventories, and other internal organizational databases that are provided only to customers, suppliers, or those who have paid for access.
Typically, users are given passwords to gain access, but more sophisticated technologies such as smart cards or special software may also be required. Many universities provide extranets for Web-based courses so that only those students enrolled in the course can access course materials and discussions.
According to John Chambers, CEO of Cisco (a leading networking technology company), the information age is the second Industrial Revolution.
True
Over the past decade or so, it has become clear that the world has changed forever. We continue to forge our way through the Information Age—the second Industrial Revolution, according to John Chambers, CEO (chief executive officer) of Cisco Systems, Inc., one of the world’s leading networking technology companies.
The first Industrial Revolution revolutionized the way people worked by introducing machines and new organizational forms. New companies and industries emerged, and old ones died off
Telecommunications is the transmission of voice and video as well as data and usually implies transmitting a longer distance than in a data communication network.
True
Data communications is the movement of computer information from one point to another by means of electrical or optical transmission systems. Such systems are often called data communications networks.
In contrast to the broader term telecommunications, which includes the transmission of voice and video (images and graphics) as well as data and usually implies longer distances. In general, data communications networks collect data from personal computers and other devices and transmit those data to a central server that is a more powerful personal computer, minicomputer, or mainframe, or they perform the reverse process, or some combination of the two.
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 shortened.
True
Collapsing the information lag to Internet speeds means that people can communicate and access information anywhere in the world regardless of their physical location. In fact, today’s problem is that we cannot handle the quantities of information we receive.
The network layer performs the same functions in both the OSI and Internet models and is responsible for routing messages from the source computer to the destination computer.
True
The network layer performs routing. It determines the next computer to which the message should be sent, so it can follow the best route through the network and finds the full address for that computer if needed.
The _________ layer is responsible for routing of messages from the sender to the final destination.
- data communication layer
- resident layer
- application layer
- network layer
network layer
The three stages of the de jure standardization process are ______________________.
- specification, identification of choices and acceptance.
- planning, implementing and acceptance.
- brainstorming, identification and implementing.
- specification, formalization, and acceptance.
specification, identification of choices and acceptance
Which is not a function of the physical layer:
- transmission of bits.
- defining the rules by which one and zeroes are
transmitted. - providing error-free transmission of data.
- providing the physical connection between sender and
receiver. - specifying the type of connection and type of signals,
waves or pulses that pass through it.
providing error-free transmission of data.
Which of the following is a function of the transport layer?
- linking the physical layer to the network layer
- formatting messages by indicating where they
start and end - deciding which route the message should take
- breaking long messages into several smaller
messages - specifying the type of connection and the
electrical - signals, radio waves, or light pulses that pass
through it
breaking long messages into several smaller messages
The American National Standards Institute:
- is the coordinating organization for the United States’
national system of standards - is a professional society in the U.S. whose standards
committees focus on local area network standards
sets the standards that govern how much of the Internet
will operate - is an agency that develops federal information
processing standards for the federal government
makes technical recommendations about global
telephone rates
is the coordinating organization for the United States’ national system of standards
