Identify four types of software licenses frequently used. Which approach does the best job of ensuring a steady, predictable stream of revenue from customers? Which approach is most fair for the...

For what are Telnet and FTP used?

Johnson & Johnson is the world's most "comprehensive and broadly based manufacturer of health care products, as well as a provider of related services, for the consumer, pharmaceutical, and medical...

What sort of benefits should the suppliers and customers of a firm that has successfully implemented an ERP system see? What sort of issues might arise for suppliers and customers during an ERP...

Assume that you work for an insurance company. Describe three applications that are critical to your business. What tools would you use to develop applications?

Your team has been hired to determine the requirements of a new medium-cost coffee bar to compete with higher priced coffee shops such as Starbucks. The new coffee bar will offer computer kiosks for...

The performance of a client-server system is influenced by two network factors: the bandwidth of the network (how many bits/sec it can transport) and the latency (how many seconds it takes for the...

Besides bandwidth and latency, what other parameter is needed to give a good characterization of the quality of service offered by a network used for digitized voice traffic?

A group of 2n - 1 router is interconnected in a centralized binary tree, with a router at each tree node. Router i communicate with router j by sending a message to the root of the tree. The root...

List two ways in which the OSI reference model and the TCP/IP reference model are the same. Now list two ways in which they differ.

The subnet of Fig. 1-25(b) was designed to withstand a nuclear war. How many bombs would it take to partition the nodes into two disconnected sets? Assume that any bomb wipes out a node and all of...

An image is 1024 x 768 pixels with 3 bytes/pixel. Assume the image is uncompressed. How long does it take to transmit it over a 56-kbps modem channel? Over a 1-Mbps cable modem, over a 10-Mbps...

Compute the Fourier coefficients for the function f (t) = t ( < t < 1).

Is an oil pipeline a simplex system, a half-duplex system, a full-duplex system, or none of the above?

An ADSL system using DMT allocates 3/4 of the available data channels to the downstream link. It uses QAM-64 modulation on each channel. What is the capacity of the downstream link?

Compare the maximum data rate of a noiseless 4-kHz channel using (a) Analog encoding (e.g., QPSK) with 2 bits per sample. (b) The T1 PCM system.

A pure sine wave of amplitude A is encoded using delta modulation, with x samples/sec. An output of +1 corresponds to a signal change of +A/8, and an output signal of -1 corresponds to a signal...

What is the essential difference between message switching and packet switching?

At the low end, the telephone system is star shaped, with all the local loops in a neighborhood converging on an end office. In contrast, cable television consists of a single long cable snaking its...

A cable TV system has 100 commercial channels, all of them alternating programs with advertising. Is this more like TDM or like FDM?

How fast can a cable user receive data if the network is otherwise idle?

Data link protocols almost always put the CRC in a trailer rather than in a header. Why?

In protocol 6, when a data frame arrives, a check is made to see if the sequence number differs from the one expected and nonak is true. If both conditions hold, a NAK is sent. Otherwise, the...

Imagine that you are writing the data link layer software for a line used to send data to you but not from you. The other end uses HDLC, with a 3-bit sequence number and a window size of seven...

Frames of 1000 bits are sent over a 1-Mbps channel using a geostationary satellite whose propagation time from the earth is 270 msec. Acknowledgements are always piggybacked onto data frames. The...

A 100-km-long cable runs at the T1 data rate. The propagation speed in the cable is 2/3 the speed of light in vacuum. How many bits fit in the cable?

PPP is based closely on HDLC, which uses bit stuffing to prevent accidental flag bytes within the payload from causing confusion. Give at least one reason why PPP uses byte stuffing instead.

Measurements of a slotted ALOHA channel with an infinite number of users show that 10 percent of the slots are idle. (a) What is the channel load, G? (b) What is the throughput? (c) Is the channel...

A LAN uses Mok and Ward's version of binary countdown. At a certain instant, the ten stations have the virtual station numbers 8, 2, 4, 5, 1, 7, 3, 6, 9, and 0. The next three stations to send are 4,...

Two CSMA/CD stations are each trying to transmit long (multi frame) files. After each frame is sent, they contend for the channel, using the binary exponential back off algorithm. What is the...

An IP packet to be transmitted by Ethernet is 60 bytes long, including all its headers. If LLC is not in use, is padding needed in the Ethernet frame, and if so, how many bytes?

Some books quote the maximum size of an Ethernet frame as 1518 bytes instead of 1500 bytes. Are they wrong? Explain your answer.

How many frames per second can gigabit Ethernet handle? Think carefully and take into account all the relevant cases. Hint: the fact that it is gigabit Ethernet matters.

Name two networks that allow frames to be packed back-to-back. Why is this feature worth having?

In Fig. 4-27, four stations, A, B, C, and D, are shown. Which of the last two stations do you think is closest to A and why?

IEEE 802.16 supports four service classes. Which service class is the best choice for sending uncompressed video?

Bluetooth supports two types of links between a master and a slave. What are they and what is each one used for?

Consider the network of Fig. 4-49(a). If machine J were to suddenly become white, would any changes be needed to the labeling? If so what?

Briefly describe the difference between store-and-forward and cut-through switches.

Consider the network of Fig. 5-7, but ignore the weights on the lines. Suppose that it uses flooding as the routing algorithm. If a packet sent by A to D has a maximum hop count of 3, list all the...

Compute a multicast spanning tree for router C in the following subnet for a group with members at routers A, B, C, D, E, F, I, and K.

Suppose that node B in Fig. 5-20 has just rebooted and has no routing information in its tables. It suddenly needs a route to H. It sends out broadcasts with TTL set to 1, 2, 3, and so on. How many...

Convert the IP address whose hexadecimal representation is C22F1582 to dotted decimal notation.

A router has just received the following new IP addresses: 57.6.96.0/21, 57.6.104.0/21, 57.6.112.0/21, and 57.6.120.0/21. If all of them use the same outgoing line, can they be aggregated, If so to...

The Protocol field used in the IPv4 header is not present in the fixed IPv6 header. Why not?

When the IPv6 protocol is introduced, does the ARP protocol have to be changed? If so, are the changes conceptual or technical?

Why does UDP exist? Would it not have been enough to just let user processes send raw IP packets?

A process on host 1 has been assigned port p, and a process on host 2 has been assigned port q. Is it possible for there to be two or more TCP connections between these two ports at the same time?

Give a potential disadvantage when Nagle's algorithm is used on a badly-congested network.

Consider the effect of using slow start on a line with a 10-msec round-trip time and no congestion. The receive window is 24 KB and the maximum segment size is 2 KB. How long does it take before the...

If the TCP round-trip time, RTT, is currently 30 msec and the following acknowledgements come in after 26, 32, and 24 msec, respectively, what is the new RTT estimate using the Jacobson algorithm?...

In a network that has a maximum TPDU size of 128 bytes, a maximum TPDU lifetime of 30 sec, and an 8-bit sequence number, what is the maximum data rate per connection?

A CPU executes instructions at the rate of 1000 MIPS. Data can be copied 64 bits at a time, with each word copied costing 10 instructions. If a coming packet has to be copied four times, can this...

According to the information given in Fig. 7-3, is little-sister.cs.vu.nl on a class A, B, or C network?

DNS uses UDP instead of TCP. If a DNS packet is lost, there is no automatic recovery. Does this cause a problem, and if so, how is it solved?

Can a machine with a single DNS name have multiple IP addresses? How could this occur?

Can a computer have two DNS names that fall in different top-level domains? If so, give a plausible example. If not, explain why not.

The number of companies with a Web site has grown explosively in recent years. As a result, thousands of companies are registered in the com domain, causing a heavy load on the top-level server for...

Some e-mail systems support a header field Content Return:. It specifies whether the body of a message is to be returned in the event of non-delivery. Does this field belong to the envelope or to the...

Electronic mail systems need directories so people's e-mail addresses can be looked up. To build such directories, names should be broken up into standard components (e.g., first name, last name) to...

A binary file is 3072 bytes long. How long will it be if encoded using base64 encoding, with a CR+LF pair inserted after every 80 bytes sent and at the end?

Using the RSA public key cryptosystem, with a = 1, b = 2, etc., a. If p = 7 and q = 11, list five legal values for d. b. If p = 13, q = 31, and d = 7, find e. c. Using p = 5, q = 11, and d = 27, find...

The SSL data transport protocol involves two nonces as well as a pre-master key. What value, if any, does using the nonces have?

Get the total number of projects supplied by supplier S1.

Show that a graph has a unique minimum spanning tree if, for every cut of the graph, there is a unique light edge crossing the cut. Show that the converse is not true by giving a counterexample.

What is a recoverable schedule? Why is recoverability of schedules desirable? Are there any circumstances under which it would be desirable to allow nonrecoverable schedules? Explain your answer.

Explain the notions of transparency and autonomy. Why are these notions desirable from a human-factors stand point?

Consider a relation that is fragmented horizontally by plant-number: Employee (name, address, salary plant-number) assumes that each fragment has two replicas: one stored at the New York site and one...

Repeat Exercise 18.1 for the case of learning to play tennis (or some other sport with which you are familiar) is this supervised learning or reinforcement learning?

Some experts believe that the growth in e-commerce will cause states and local governments to lose tax revenue, unless Internet transactions are subject to sales tax. What is one argument that...

Should the IT director report to the company president, or somewhere else? Does it matter?

Research newspaper, business magazine articles, or the Web to find IT companies whose stock is traded publicly. Choose a company and pretend to buy $5,000 of its stock. Why did you choose that...

Visit at least three Web sites to learn more about agile system development and spiral models. Prepare a list of the sites you visited and a summary of the results.

What is information technology and why is it important? Suggest three fictitious headlines that might be added to Figure 1-1 on page2. Can Google Avoid Global Censorship? Web Sales Surge as Gas...

You are the IT manager at Hi-Voltage Components, a medium-sized firm that makes specialized circuit boards. Hi-Voltages largest customer, Green Industries, recently installed a computerized...

Identify and briefly describe five common fact-finding methods.

Would you continue to work for a company if you disagreed with the firms mission statement? Why or why not?

What is a task? What is an event? What is a milestone?

What specific information do you need to create a work breakdown structure?

Explain the differences between a Gantt chart and a PERT/CPM chart.

What formula can a project manager use to estimate task duration? Provide an example.

Why is it important to deliver effective project reports and communications?

What is the Hawthorne Effect? Have you ever experienced it? When and where?

1. In business process modeling notation, a gateway is like a fork in the road, allowing the flow to go one way or another. You can learn more about gateways in the Visible Analyst Glossary feature....

Define an object, and provide three examples.

Define a method, and provide three examples.

Define encapsulation, and explain how it is used in object-oriented analysis.

Define polymorphism, and provide three examples.

Provide suggestions for reducing input volume.

What is the most important Information Technology (IT) security issues facing companies today? Have these changed in the last five years, and will they continue to change? How should companies...

Why is practice so important when preparing a presentation? Provide a specific example from your own experience.

How do you know if a project is economically feasible? Why is TCO important?

In Chapter 4, you saw the creation of the Tiny College database design. That design reflected such business rules as a professor may advise many students and a professor may chair one department....

Find the customer balance summary for all customers who have not made purchases during the current invoicing period. The results are shown inFigure. Total Balances Minimum Balanace Maximum Balance...

In general, what are the strategies for exploiting spatial locality and temporal locality?

What is the kernel of an OS?

List and briefly explain five storage management responsibilities of a typical OS.

What is swapping and what is its purpose?

For the seven-state process model of Figure, draw a queuing diagram similar to that of Figure 3.8b. New 6 Suspend K Activate Dispatch ReleaseExit Ready/ suspen Ready unning Suspend Time-out Activate...

What is the distinction between competing processes and cooperating processes?