A beam of light moves from one medium to another medium with less density. The critical angle is 60. Do we have refraction or reflection for each of the following incident angles? Show the bending of...

Figure 8.28 shows a switch in a virtual-circuit network. Find the output port and the output VCI for packets with the following input port and input VCI addresses: a. Packet 1: 3, 78 b. Packet 2: 2,...

Using Figure 7.16, tabulate the attenuation (in dB) of an optical fiber for the indicated wavelength and distances. Figure 7.16 100 50 10 0.5 0.1 0.05 0.01 800 1000 1200 1400 1600 1800 Wavelength...

Assume that a voice channel occupies a bandwidth of 4 kHz. We need to multiplex 10 voice channels with guard bands of 500 Hz using FDM. Calculate the required bandwidth.

A cable company uses one of the cable TV channels (with a bandwidth of 6 MHz) to provide digital communication for each resident. What is the available data rate for each resident if the company uses...

The telephone line has 4 KHz bandwidth. What is the maximum number of bits we can send using each of the following techniques? Let d = 0. a. ASK b. QPSK c. 16-QAM d. 64-QAM

What is the required bandwidth for the following cases if we need to send 4000 bps? Let d = 1. a. ASK b. FSK with 2f = 4 KHz c. QPSK d. 16-QAM

Draw the constellation diagram for the following: a. ASK, with peak amplitude values of 1 and 3 b. BPSK, with a peak amplitude value of 2 c. QPSK, with a peak amplitude value of 3 d. 8-QAM with two...

Calculate the baud rate for the given bit rate and type of modulation. a. 2000 bps, FSK b. 4000 bps, ASK c. 6000 bps, QPSK d. 36,000 bps, 64-QAM

Consider an n k crossbar switch with n inputs and k outputs. a. Can we say that the switch acts as a multiplexer if n > k? b. Can we say that the switch acts as a demultiplexer if n < k?

An NRZ-I signal has a data rate of 100 Kbps. Using Figure 4.6, calculate the value of the normalized energy (P) for frequencies at 0 Hz, 50 KHz, and 100 KHz. Figure 4.6 10 | 0 | 1 0 | r = 1 Save =...

Define a DC component and its effect on digital transmission.

How many bits can fit on a link with a 2 ms delay if the bandwidth of the link is a. 1 Mbps? b. 10 Mbps? c. 100 Mbps?

We need to upgrade a channel to a higher bandwidth. Answer the following questions: a. How is the rate improved if we double the bandwidth? b. How is the rate improved if we double the SNR?

What is the theoretical capacity of a channel in each of the following cases? a. Bandwidth: 20 KHz SNR dB = 40 b. Bandwidth: 200 KHz SNR dB = 4 c. Bandwidth: 1 MHz SNR dB = 20

The attenuation of a signal is 10 dB. What is the final signal power if it was originally 5 W?

Is the frequency domain plot of an alarm system discrete or continuous?

What is the frequency of the signal in Figure 3.36? 4 ms Time

Can we say whether a signal is periodic or nonperiodic by just looking at its frequency domain plot? How?

What is the phase shift for the following? a. A sine wave with the maximum amplitude at time zero b. A sine wave with maximum amplitude after 1/4 cycle c. A sine wave with zero amplitude after 3/4...

Unstuff the following frame payload in which E is the escape byte, F is the flag byte, and D is a data byte other than an escape or a flag character. D DEF E D DD DE E

Assume the network in Figure 9.7 does not support broadcasting. What do you suggest for sending the ARP request in this network? Figure 9.7 LAN System A System B N, L, N, L2 Request N3L3 N, L4...

In a slotted Aloha network with G = 1/2, how is the throughput affected in each of the following cases? a. G is increased to 1. b. G is decreased to 1/4.

In the previous problem, we showed that the throughput is S = Ge 2G for a pure Aloha network and S = Ge G for a slotted Aloha network. In this problem, we want to find the value of G in each network...

To understand the uses of K in Figure 12.13, find the probability that a station can send immediately in each of the following cases: Figure 12.13 a. After one failure. b. After four failures....

Assume the propagation delay in a broadcast network is 5 s and the frame transmission time is 10 s. a. How long does it take for the first bit to reach the destination? b. How long does it take for...

We have a pure ALOHA network with a data rate of 10 Mbps. What is the maximum number of 1000-bit frames that can be successfully sent by this network?

Can the value of a traditional checksum be all 0s (in binary)? Defend your answer.

Assume we are sending data items of 16-bit length. If two data items are swapped during transmission, can the traditional checksum detect this error? Explain.

Consider Figure 1. 1 (b). Suppose that each link between the server and the client has a packet loss probability p, and the packet loss probabilities for these links are independent. What is the...

Consider the rt2.2 receiver in Figure 3.14, and the creation of a new packet in the se1f-ansition (i.e., the transition from the state back to itself) in the Waifor-0-from-below arid the...

Consider the previous problem, but suppose that D has the value a. 1001010101. b. 0101101010. c. 1010100000.

In Section 8.6. 1, it is shown that without sequence numbers, Trudy (a woman- in-the middle) can wreak havoc in an SSL session by interchanging TCP segments. Can Trudy do something similar by...

What is a private network address? Should a data-gram with a private network address ever be present in the larger public Internet? Explain.

Suppose that the receiver in Figure 7.6 wanted to receive the data being sent by sender 2. Show (by calculation) that the receiver is indeed able to recover sender 2s data from the aggregate channel...

Suppose that all the switches in Figure 6.15 are replaced by hubs. All links are 100 Mbps. Now answer the questions posed in problem P23. Data From Problem 6.23 Consider Figure 6.15. Suppose that all...

Consider Figure 6.15. Suppose that all links arc loo Mbps. What is the maximum total aggregate throughput that can be achieved among the 9 hosts and 2 servers in this network? You can assume that any...

Consider a TCP connection between Host A and Host B. Suppose that the TCP segments traveling from Host A to Host B have source port number x and destination port number y. What are the source and...

A simple telephone system consists of two end offices and a single toll office to which each end office is connected by a 1-MHz full-duplex trunk. The average telephone is used to make four calls per...

Suppose that a message 1001 1100 1010 0011 is transmitted using Internet Checksum (4-bit word). What is the value of the checksum?

Suppose that the fie measured Sample RTT values (see Section 3.5.3) are 106 ms, 120 ms, 140 ins, 90 ms, and 115 ms. Compute the EstimateedRTT after each of these Sample RTT values is obtained, using...

What is the baud rate of classic 10-Mbps Ethernet?

The actual layout of cells is seldom as regular that as shown in Fig. 2-45. Even the shapes of individual cells are typically irregular. Give a possible reason why this might be. How do these...

List two ways in which WiMAX is similar to 802.11, and two ways in which it is different from 802.11.

Consider the network of Fig. 5-12(a). Distance vector routing is used, and the following vectors have just come in to router C: from B: (5, 0, 8, 12, 6, 2); from D: (16, 12, 6, 0, 9, 10); and from E:...

Suppose that you want to send an MP3 file to a friend, but your friends ISP limits the size of each incoming message to 1 MB and the MP3 file is 4 MB. Is there a way to handle this situation by using...

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...

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.

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...

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...

List some strategies in CSMA/CA that are used to avoid collision.

Calculate the minimum time required to download one million bytes of information using a 56K modem.

Repeat Problem P14-7 using a cable modem (consider the minimum rates). Problem P14-7 Calculate the minimum time required to download one million bytes of information using a 56K modem.

A stream of data is being carried by STS-1 frames. If the data rate of the stream is 49.540 Mbps, how many STS-1 frames per second must let their H3 bytes carry data?

What is the relationship between TPs, VPs, and VCs?

A program to simulate the calculation of CRC.

A program to simulate the calculation of traditional checksum.

In an 802.11, give the value of the address 3 field in each of the following situations (left bit defines To DS and right bit defines From DS). a. 00 b. 01 c. 10 d. 11

Assume a frame moves from a wireless network using the 802.11 protocol to a wired network using the 802.3 protocol. Show how the field values in the 802.3 frame are filled with the values of the...

A BSS ID (BSSID) is a 48-bit address assigned to a BSS in an 802.11 network. Do some research and find what the use of the BSSID is and how BSSIDs are assigned in ad hoc and infrastructure networks.

In an 802.11 communication, the size of the payload (frame body) is 1200 bytes. The station decides to fragment the frame into three fragments, each of 400 payload bytes. Answer the following...

Repeat the previous problem (Figure 15.24), but assume that the distribution system is also wireless. AP1 is connected to AP2 through a wireless channel. Show the value of addresses in all...

What is the role of the radio layer in Bluetooth?

In an 802.11 network, assume station A has four fragments to send to station B. If the sequence number of the first fragment is selected as 3273, what are the values of the more fragment flag,...

Fill in the blanks. The 83.5 MHz bandwidth in Bluetooth is divided into_____ channels, each of ______ MHz.

An 802.11 network may use four different interframe spaces (IFSs) to delay the transmission of a frame in different situations. This allows low-priority traffic to wait for high-priority traffic when...

Draw a cell pattern with a frequency-reuse factor of 3.

What is the maximum number of callers in each cell in AMPS?

What is the piece of information in a packet upon which the forwarding decision is made in each of the following approaches to switching? a. Datagram approach b. Virtual-circuit approach

In classless addressing, show the whole address space as a single block using the CIDR notation.

Do we have any of the following services at the network layer of TCP/IP? If not, why? a. flow control b. error control c. congestion control

In classless addressing, what is the size of the block (N) if the value of the prefix length (n) is one of the following? a. N = 0 b. N = 14 c. N = 32

Change each of the following prefix lengths to a mask in dotted-decimal notation: a. N = 0 b. N = 14 c. N = 30

In classless addressing, can two different blocks have the same prefix length? Explain.

Which fields in the datagram is(are) responsible for gluing together all fragments belonging to an original datagram?

OSPF messages and ICMP messages are directly encapsulated in an IP datagram. If we intercept an IP datagram, how can we tell whether the payload belongs to OSPF or ICMP?

OSPF messages are exchanged between routers. Does this mean that we need to have OSPF processes run all the time to be able to receive an OSPF message when it arrives?

Why do you think RIP uses UDP instead of TCP?

Assume that we have an isolated AS running RIP. We can say that we have at least two different kinds of datagram traffic in this AS. The first kind carries the messages exchanged between hosts; the...

List three types of autonomous systems (ASs) described in the text, and make a comparison between them.

A router using DVMRP receives a packet with source address 10.14.17.2 from interface 2. If the router forwards the packet, what are the contents of the entry related to this address in the unicast...

We say that a router in DVMRP creates a shortest-path tree on demand. What is the meaning of this statement? What is the advantage of creating shortest path trees only on demand?

Decompress the following addresses and show the complete unabbreviated IPv6 address: a. ::2222 b. 1111:: c. B:A:CC::1234:A

In a network, the size of the send window is 20 packets. Which of the following protocols is being used by the network? a. Stop-and-Wait b. Go-Back-N c. Selective-Repeat

A client uses UDP to send data to a server. The data length is 16 bytes. Calculate the efficiency of this transmission at the UDP level (ratio of useful bytes to total bytes).

Compare the TCP header and the UDP header. List the fields in the TCP header that are not part of the UDP header. Give the reason for each missing field.

In TCP, if the value of HLEN is 0111, how many bytes of options are included in the segment?

In TCP, how many sequence numbers are consumed by each of the following segments? a. SYN b. ACK c. SYN + ACK d. Data

A client uses TCP to send data to a server. The data consist of 16 bytes. Calculate the efficiency of this transmission at the TCP level (ratio of useful bytes to total bytes).

TCP is sending data at 1 megabyte per second. If the sequence number starts with 7000, how long does it take before the sequence number goes back to zero?

Assume Alice, the client, creates a TCP connection with Bob, the server. They exchange data and close the connection. Now Alice starts a new connection with Bob by sending a new SYN segment. The...

As we have explained in the text, the TCP sliding window, when used without new SACK options, is a combination of the Go-Back-N and the Selective- Repeat protocols. Explain which aspects of the TCP...

If the client in the previous exercise sends 7600 data chunks and the server sends 570 data chunks, show the contents of the three packets exchanged during association termination. Previous Exercise...

Create the table that results from applying an INTERSECT relational operator to the tables shown in Fig Q3.13. Figure Q3.13: Database name: Ch03_VendingCo Table name: MACHINE MACHINE_PRODUCT...

Tiny College wants to keep track of the history of all administrative appointments (date of appointment and date of termination). The Tiny College chancellor may want to know how many deans worked in...

What string function should you use to list the first three characters of a companys EMP_LNAME values? Give an example, using a table named EMPLOYEE.

What two things must a SQL programmer understand before beginning to craft a SELECT query?

What type of integrity is enforced when a primary key is declared?

What is the purpose of a CHECK constraint?

What is the difference between a name node and a data node in HDFS?