All Matches
Solution Library
Expert Answer
Textbooks
Search Textbook questions, tutors and Books
Oops, something went wrong!
Change your search query and then try again
Toggle navigation
FREE Trial
S
Books
FREE
Tutors
Study Help
Expert Questions
Accounting
General Management
Mathematics
Finance
Organizational Behaviour
Law
Physics
Operating System
Management Leadership
Sociology
Programming
Marketing
Database
Computer Network
Economics
Textbooks Solutions
Accounting
Managerial Accounting
Management Leadership
Cost Accounting
Statistics
Business Law
Corporate Finance
Finance
Economics
Auditing
Ask a Question
Search
Search
Sign In
Register
study help
computer science
computer networking
Questions and Answers of
Computer Networking
Compare the data rates for Standard Ethernet, Fast Ethernet, Gigabit Ethernet, and 10 Gigabit Ethernet.
What is the hexadecimal equivalent of the following Ethernet address?01011010 00010001 01010101 00011000 10101010 00001111
Why is there no need for CSMA/CD on a full-duplex Ethernet LAN?
Check to see if the following set of chips can belong to an orthogonal system. [+1, +1, +1, +1] , [+1,1,1, +1], [1, +1, +1, 1] , [+1, 1, 1, +1]
Check to see if the following set of chips can belong to an orthogonal system.[+1, +1] and [+1, −1]
List some strategies in CSMA/CA that are used to avoid collision.
Answer the following questions:a. Can a routing table in a datagram network have two entries with the same destination address? Explain.b. Can a switching table in a virtual-circuit network have two
Based on Figure 12.13, how do we interpret success in an Aloha network?Figure 12.13 Figure 12.13 Flow diagram for the CSMA/CD Station has a frame to send K=0 Legend T Frame average transmission time
Redraw Figure 11.11 using a variable to hold the one-bit sequence number and a variable to hold the one-bit acknowledgment number.Figure 11.11 Figure 11.11 FSM for the Stop-and-Wait protocol Sending
In Figure 11.11, do the ready and blocking states use the same timer? Explain.Figure 11.11 Figure 11.11 FSM for the Stop-and-Wait protocol Sending node Packet came from network layer. Make a frame,
Using the following specifications, draw a finite state machine with three states (I, II, and III), six events, and four actions:a. If the machine is in state I, two events can occur. If event 1
Using the following specifications, draw a finite state machine with three states (I, II, and III), five events, and six actions:a. If the machine is in state I, two events can occur. If event 1
In the Stop-and-Wait Protocol, assume that the sender has only one slot in which to keep the frame to send or the copy of the sent frame. What happens if the network layer delivers a packet to the
Redraw Figure 11.2 using the following scenario:Figure 11.2a. Frame 0 is sent, but lost.b. Frame 0 is resent and acknowledged.c. Frame 1 is sent and acknowledged, but the acknowledgment is lost.d.
Compare and contrast flow control and error control.
Redraw Figure 11.12 using the following scenario:Figure 11.12a. The first frame is sent and acknowledged.b. The second frame is sent and acknowledged, but the acknowledgment is lost.c. The second
In the previous problem we tried to find the number of bits to be added to a dataword to correct a single-bit error. If we need to correct more than one bit, the number of redundant bits increases.
In the interleaving approach to FEC, assume each packet contains 10 samples from a sampled piece of music. Instead of loading the first packet with the first 10 samples, the second packet with the
Manually simulate the Fletcher algorithm (Figure 10.18) to calculate the checksum of the following bytes: (2B)16, (3F)16, (6A)16, and (AF)16. Also show that the result is a weighted checksum.Figure
Assume a packet is made only of four 16-bit words (A7A2)16, (CABF)16, (903A)16, and (A123)16. Manually simulate the algorithm in Figure 10.17 to find the checksum.Figure 10.17 Figure 10.17 Algorithm
Traditional checksum calculation needs to be done in one’s complement arithmetic. Computers and calculators today are designed to do calculations in two’s complement arithmetic. One way to
This problem shows a special case in checksum handling. A sender has two data items to send: (4567)16 and (BA98)16. What is the value of the checksum?
We have sampled a low-pass signal with a bandwidth of 200 KHz using 1024 levels of quantization.a. Calculate the bit rate of the digitized signal.b. Calculate the SNRdB for this signal.c. Calculate
Using the code in Table 10.2, what is the dataword if each of the following codewords is received?Table 10.2a. 01011b. 11111c. 00000d. 11011 Table 10.2 Simple parity-check code C(5, 4) Dataword
In Figures 9.11 to 9.13, both the forwarding table and ARP are doing a kind of mapping. Show the difference between them by listing the input and output of mapping for a forwarding table and
Why is it better not to change an end-to-end address from the source to the destination?
In Figure 9.7, do you think that system A should first check its cache for mapping from N2 to L2 before even broadcasting the ARP request?Figure 9.7 Figure 9.7 ARP operation LAN System A System B
In Figure 9.5, show the process of frame change in routers R1 and R2.Figure 9.5 Figure 7.5 UTP connector 12345678 2343678 RJ-45 Female RJ-45 Male
Redesign the configuration of Problem 8-12 using the Clos criteria.Problem 8-12We need a three-stage space-division switch with N = 100. We use 10 crossbars at the first and third stages and 4
Repeat Problem 8-12 if we use 6 crossbars at the middle stage.Problem 8-12We need a three-stage space-division switch with N = 100. We use 10 crossbars at the first and third stages and 4 crossbars
When we talkabout the broadcast address in a link, do we mean sending a message to all hosts and routers in the link or to all hosts and routers in the Internet? In other words, does a broadcast
In the previous problem, do we need both network and data-link layers?Previous ProblemAssume we have an internet (a private small internet) in which all hosts are connected in a mesh topology. Do we
Assume we have an internet (a private small internet) in which all hosts are connected in a mesh topology. Do we need routers in this internet? Explain.
We need a three-stage time-space-time switch with N = 100. We use 10 TSIs at the first and third stages and 4 crossbars at the middle stage.a. Draw the configuration diagram.b. Calculate the total
The horizontal axes in Figures 7.6 and 7.9 represent frequencies. The horizontal axis in Figure 7.16 represents wavelength. Can you explain the reason? If the propagation speed in an optical fiber is
Use the results of Problem P7-4 to infer that the bandwidth of a coaxial cable decreases with the increase in distance.Problem P7-4Using Figure 7.9, tabulate the attenuation (in dB) of a 2.6/9.5 mm
Use the results of Problem P7-1 to infer that the bandwidth of a UTP cable decreases with an increase in distance.Problem 7-1Using Figure 7.6, tabulate the attenuation (in dB) of a 18-gauge UTP for
An entry in the switching table of a virtual-circuit network is normally created during the setup phase and deleted during the teardown phase. In other words, the entries in this type of network
We mentioned that two types of networks, datagram and virtual-circuit, need a routing or switching table to find the output port from which the information belonging to a destination should be sent
Five equal-size datagrams belonging to the same message leave for the destination one after another. However, they travel through different paths as shown in Table 8.1.We assume that the delay
Repeat Problem 6-4 if each output slot carries 2 bits from each source.Problem 6-4We need to use synchronous TDM and combine 20 digital sources, each of 100 Kbps. Each output slot carries 1 bit from
Show the contents of the five output frames for a synchronous TDM multiplexer that combines four sources sending the following characters. Note that the characters are sent in the same order that
Distinguish between a link and a channel in multiplexing.
An analog signal has a bandwidth of 20 KHz. If we sample this signal and send it through a 30 Kbps channel, what is the SNRdB?
Repeat Problem P4-3 for the differential Manchester scheme.Problem 4-3Draw the graph of the NRZ-L scheme using each of the following data streams, assuming that the last signal level has been
Repeat Problem P4-3 for the Manchester scheme.Problem 4-3Draw the graph of the NRZ-L scheme using each of the following data streams, assuming that the last signal level has been positive. From the
Repeat Problem P4-3 for the NRZ-I scheme.Problem 4-3Draw the graph of the NRZ-L scheme using each of the following data streams, assuming that the last signal level has been positive. From the
List three techniques of digital-to-digital conversion.
The light of the sun takes approximately eight minutes to reach the earth. What is the distance between the sun and the earth?
If the bandwidth of the channel is 5 Kbps, how long does it take to send a frame of 100,000 bits out of this device?
Is the frequency domain plot of a voice signal discrete or continuous?
Using the internet in Figure 1.11 (Chapter 1) in the text, show the layers of the TCP/IP protocol suite and the flow of data when two hosts, one on the west coast and the other on the east coast,
Which of the following data units has an application-layer message plus the header from layer 4?a. A frameb. A user datagramc. A bit
Which of the following data units is decapsulated from a user datagram?a. A datagramb. A segmentc. A message
Which of the following data units is encapsulated in a frame?a. A user datagramb. A datagramc. A segment
Explain the difference between an Internet draft and a proposed standard.
What is the first principle we discussed in this chapter for protocol layering that needs to be followed to make the communication bidirectional?
When a resident uses a dial-up or DLS service to connect to the Internet, what is the role of the telephone company?
In a LAN with a link-layer switch (Figure 1.8b), Host 1 wants to send a message to Host 3. Since communication is through the link-layer switch, does the switch need to have an address?
Why are protocols needed?
Assume six devices are arranged in a mesh topology. How many cables are needed? How many ports are needed for each device?
Although it was not mentioned in the text, an alternative form for a URL is to use the IP address instead of its DNS name. Use this information to explain why a DNS name cannot end with a digit.
A binary file is 4560 bytes long. How long will it be if encoded using base 64 encoding, with a CR+LF pair inserted after every 110 bytes sent and at the end?
On the day of a major sporting event, such as the championship game in some popular sport, many people go to the official Web site. Is this a flash crowd in the same sense as the 2000 Florida
Assume that compression is not used for audio CDs. How many MB of data must the compact disc contain in order to be able to play two hours of music?
In Fig. 7-42(c), quantization noise occurs due to the use of 4-bit samples to represent nine signal values. The first sample, at 0, is exact, but the next few are not. What is the percent error for
An audio streaming server has a one-way ‘‘distance’’ of 100 msec to a media player. It outputs at 1 Mbps. If the media player has a 2-MB buffer, what can you say about the position of the
What is the bit rate for transmitting uncompressed 1200 × 800 pixel color frames with 16 bits/pixel at 50 frames/sec?
Consider a 50,000-customer video server, where each customer watches three movies per month. Two-thirds of the movies are served at 9 P.M. How many movies does the server have to transmit at once
Break the following monoalphabetic substitution cipher. The plaintext, consisting of letters only, is an excerpt from a poem by Lewis Carroll.mvyy bek mnyx n yvjjyr snijrh invq n muvjvdt je n idnvy
An affine cipher is a version of a mono-alphabetic substitution cipher, in which the letters of an alphabet of size m are first map to the integers in the range 0 to m-1. Subsequently, the integer
Alice used a transposition cipher to encrypt her messages to Bob. For added security, she encrypted the transposition cipher key using a substitution cipher, and kept the encrypted cipher in her
Find a 77-bit one-time pad that generates the text Hello World from the cipher text of Fig. 8-4.Figure 8-4 Message 1: Pad 1: Ciphertext: 1001001
You are a spy, and, conveniently, have a library with an infinite number of books at your disposal. Your operator also has such a library at his disposal. You have agreed to use Lord of the Rings as
Quantum cryptography requires having a photon gun that can, on demand, fire a single photon carrying 1 bit. In this problem, calculate how many photons a bit carries on a 250-Gbps fiber link. Assume
In the text, we computed that a cipher-breaking machine with a million processors that could analyze a key in 1 nanosecond would take 1016 years to break the 128-bit version of AES. Let us compute
Suppose that a message has been encrypted using DES in counter mode. One bit of cipher text in block Ci is accidentally transformed from a 0 to a 1 during transmission. How much plain text will be
Using the RSA public key cryptosystem, with a = 1, b = 2 . . . y = 25, z = 26.(a) If p = 5 and q = 13, list five legal values for d.(b) If p = 5, q = 31, and d = 37, find e.(c) Using p = 3, q = 11,
Alice and Bob use RSA public key encryption in order to communicate between them. Trudy finds out that Alice and Bob shared one of the primes used to determine the number n of their public key pairs.
A math class has 25 students. Assuming that all of the students were born in the first half of the year—between January 1st and June 30th— what is the probability that at least two students have
Alice wants to send a message to Bob using SHA-1 hashes. She consults with you regarding the appropriate signature algorithm to be used. What would you suggest?
Suppose an organization uses VPN to securely connect its sites over the Internet. Jim, a user in the organization, uses the VPN to communicate with his boss, Mary. Describe one type of communication
The Diffie-Hellman key exchange is being used to establish a secret key between Alice and Bob. Alice sends Bob (227, 5, 82). Bob responds with (125). Alice’s secret number, x, is 12, and Bob’s
Two users can establish a shared secret key using the Diffie-Hellman algorithm, even if they have never met, share no secrets, and have no certificates(a) Explain how this algorithm is susceptible to
Is it possible to multicast a PGP message? What restrictions would apply?
Point-of-sale terminals that use magnetic-stripe cards and PIN codes have a fatal flaw: a malicious merchant can modify his card reader to log all the information on the card and the PIN code in
Alice is using the public-key authentication protocol of Fig. 8-43 to authenticate communication with Bob. However, when sending message 7, Alice forgot to encrypt RB. Trudy now knows the value of
Imagine that you have trained your St. Bernard, Bernie, to carry a box of three 8-mm tapes instead of a flask of brandy. (When your disk fills up, you consider that an emergency.) These tapes each
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 (i) Digitized voice traffic? (ii) Video
What are two reasons for using layered protocols? What is one possible disadvantage of using layered protocols?
The president of the Specialty Paint Corp. gets the idea to work with a local beer brewer to produce an invisible beer can (as an anti-litter measure). The president tells her legal department to
The Internet is roughly doubling in size every 18 months. Although no one really knows for sure, one estimate put the number of hosts on it at 600 million in 2009. Use these data to compute the
Mobile phone network operators need to know where their subscribers’ mobile phones (hence their users) are located. Explain why this is bad for users. Now give reasons why this is good for users.
An image is 1600 × 1200 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
Suppose the algorithms used to implement the operations at layer k is changed. How does this impact operations at layers k − 1 and k + 1?
Suppose there is a change in the service (set of operations) provided by layer k. How does this impact services at layers k-1 and k+1?
Provide a list of reasons for why the response time of a client may be larger than the best-case delay.
What are the disadvantages of using small, fixed-length cells in ATM?
In the Internet File Server example (Figure 6-6), can the connect( ) system call on the client fail for any reason other than listen queue being full on the server? Assume that the network is
In Figure 6-20, suppose a new flow E is added that takes a path from R1 to R2 to R6. How does the max-min bandwidth allocation change for the five flows?
Showing 1300 - 1400
of 2026
First
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21