Rewrite the following IP addresses using dotted-decimal notation: a. 01011110 10110000 01110101 00010101 b. 10001001 10001110 11010000 00110001 c. 01010111 10000100 00110111 00001111

If a label in a connection-oriented service is 8 bits, how many virtual circuits can be established at the same time?

In Figure 18.10, assume that the link between R1 and R2 is upgraded to 170 kbps and the link between the source host and R1 is now downgraded to 140 kbps. What is the throughput between the source...

Which of the following cannot be a mask in CIDR? a. 255.225.0.0 b. 255.192.0.0 c. 255.255.255.6

Assume we have an internet with an 8-bit address space. The addresses are equally divided between four networks (N 0 to N 3 ). The internetwork communication is done through a router with four...

Assume we have an internet with a 12-bit address space. The addresses are equally divided between eight networks (N 0 to N 7 ). The internetwork communication is done through a router with eight...

Assume we have an internet with a 9-bit address space. The addresses are divided between three networks (N 0 to N 2 ), with 64, 192, and 256 addresses respectively. The internetwork communication is...

Can router R1 in Figure 18.35 receive a packet with destination address 140.24.7.194? What will happen to the packet if this occurs? Figure 18.35 Figure 18.35 Longest mask matching 140.24.7.0/26...

In Figure 19.4, show how the sum, wrapped sum, and checksum can be calculated when each word (16 bits) is created instead of waiting for the whole packet to be created. Figure 19.4 Example of...

In Figure 19.4, show how the sum, wrapped sum, and checksum can be calculated when the words are given in decimal numbers (the way the words are stored in a computer memory). Figure 19.4 Example of...

Briefly describe how we can defeat the following security attacks: a. Packet sniffing b. Packet modification c. IP spoofing

Explain when each of the following attributes can be used in BGP: a. LOCAL-PREF b. AS-PATH c. NEXT-HOP

Can a router combine the advertisement of a link and a network in a single link-state update?

Explain what type of OSPF link state is advertised in each of the following cases: a. A router needs to advertise the existence of another router at the end of a point-to-point link. b. A router...

In computer science, when we encounter an algorithm, we often need to ask about the complexity of that algorithm (how many computations we need to do). To find the complexity of Dijkstras algorithm,...

Why do you think we need only one RIP update message, but several OSPF update messages?

At any moment, a RIP message may arrive at a router that runs RIP as the routing protocol. Does it mean that the RIP process should be running all the time?

Is the path-vector routing algorithm closer to the distance-vector routing algorithm or to the link-state routing algorithm? Explain.

Write a program to simulate the distance-vector algorithm (Table 20.1). for (y = 1 to N) { if (y is a neighbor) D[y] = c[myself][y] else 10 D[y] = 0 11 } send vector {D[1], D[2], ..., D[N]} to all...

Exactly describe why we cannot use the CIDR notation for the following blocks in Table 21.1: a. AD HOC block with the range 224.0.2.0 to 224.0.255.255. b. The first reserved block with the range...

Define which of the following addresses are multicast addresses: a. 224.8.70.14 b. 226.17.3.53 c. 240.3.6.25

Define the group of each of the following multicast addresses (local network control block, internetwork control block, SSM block, Glop block, or administratively scoped block): a. 224.0.1.7 b....

A multicast router is connected to four networks. The interest of each network is shown below. What is the group list that should be advertised by the router? a. N1: {G1, G2, G3} b. N2: {G1, G3} c....

Assume that m is much less than n and that router R is connected to n networks in which only m of these networks are interested in receiving packets related to group G. How can router R manage to...

Does RPB actually create a shortest path tree? Explain. What are the leaves of the tree?

Does RPM actually create a shortest path tree? Explain. What are the leaves of the tree?

List three steps that a DVMRP router uses to create a source-based tree. Which phase is responsible for creating the part of the tree from the source to the current router? Which phase is responsible...

Explain why an MOSPF router can create the shortest path with the source as the root in one step, but DVMRP needs three steps to do so.

Explain why PIM is called Protocol Independent Multicast.

Which version of PIM uses the first and the third steps of DVMRP? What are these two steps?

Router A sends a unicast RIP update packet to router B that says 134.23.0.0/16 is 7 hops away. Network B sends an update packet to router A that says 13.23.0.0/16 is 4 hops away. If these two routers...

Find the interface identifier if the physical address of the EUI is (F5-A9-23-AA-07-14-7A-23) 16 using the format we defined for Ethernet addresses.

An organization is assigned the block 2000:1110:1287/48. What is the IPv6 address of an interface in the third subnet if the IEEE physical address of the computer is (F5-A9-23-14-7A-D2) 16 .

A sender sends a series of packets to the same destination using 5-bit sequence numbers. If the sequence numbers start with 0, what is the sequence number of the 100th packet?

Using 5-bit sequence numbers, what is the maximum size of the send and receive windows for each of the following protocols? a. Stop-and-Wait b. Go-Back-N c. Selective-Repeat

Create a scenario similar to Figure 23.22 in which the sender sends three packets. The first and second packets arrive and are acknowledged. The third packet is delayed and resent. The duplicate...

Redraw Figure 23.35 if the sender sends 5 packets (0, 1, 2, 3, and 4). Packets 0, 1, and 2 are received in order and acknowledged, one by one. Packet 3 is delayed and received after packet 4.

Assume we need to design a Go-Back-N sliding-window protocol for a network in which the bandwidth is 100 Mbps and the average distance between the sender and receiver is 10,000 km. Assume the average...

Some of the application programs can use the services of two transport-layer protocols (UDP or TCP). When a packet arrives at the destination, how can the computer find which transport layer is...

In TCP, how do we define the sequence number of a segment (in each direction)? Consider two cases: the first segment and other segments.

In TCP, we have two consecutive segments. Assume the sequence number of the first segment is 101. What is the sequence number of the next segment in each of the following cases? a. The first segment...

For a clearer view of Nagles algorithm, let us repeat the previous problem, but let the server transport layer acknowledge a segment when there is a previous segment that has not been acknowledged...

Assume a TCP server expects to receive byte 2001, but it receives a segment with sequence number 2200. What is the reaction of the TCP server to this event? Can you justify the reaction?

You know that the domain name of a computer is aBusiness.com. Write a statement in Java to create an InetAddress object associated with that computer.

Why do you think that Java provides no constructors for the InetAddress class?

You know that the IP address of a computer is 23.14.76.44. Write a statement in Java to create an InetAddress object associated with this address.

Why do you think that Java uses an instance of a class instead of just an integer to represent an IP address?

A port number in the TCP/IP protocol suite is an unsigned 16-bit integer. How can we represent a port number in Java using a 32-bit integer?

How does Java distinguish between IPv4 and IPv6 addresses?

How is an IP address represented in Java?

In Figure 25.12 in the text, how is the socket created for data transfer at the server site? Figure 25.12 Figure 25.12 Socket data structure Length Family Port number IP address Family Type Protocol...

Write a program to make the UDP client program in Table 25.2 more generic to be able to send any request created by the client program. Table 25.2 Echo client program using UDP I/ UDP echo client...

Explain which entity provides service and which one receives service in the client-server paradigm.

Assume we want to make the TCP client program in Table 25.2 more generic to be able to send a string and to handle the response received from the server. Show how this can be done. Table 25.2 Echo...

Write a program to make the TCP server program in Table 25.3 more generic: to receive a request, to process the request, and to send back the response. Table 25.3 Echo server program using the...

A source socket address is a combination of an IP address and a port number. Explain what each section identifies.

Can a host use a TELNET client to get services provided by other clientserver applications such as FTP or HTTP?

In FTP, a user (Maria) wants to move a file named file1 from /usr/users/report directory to the directory /usr/top/letters. Note that this is a case of renaming a file. We first need to give the name...

The TELNET application has no commands such as those found in FTP or HTTP to allow the user to do something such as transfer a file or access a web page. In what way can this application be useful?

In FTP, a user (Jan) wants to make a new directory called Jan under the directory/usr/usrs/letters. Show all of the commands and responses.

Assume a TELNET client uses ASCII to represent characters, but the TELNET server uses EBCDIC to represent characters. How can the client log into the server when character representations are...

In FTP, a user (Jane) wants to retrieve an EBCDIC file named huge from /usr/users/report directory using the ephemeral port 61017. The file is so large that the user wants to compress it before it is...

Alice has been on a long trip without checking her e-mail. She then finds out that she has lost some e-mails or attachments her friends claim they have sent to her. What can be the problem?

In Chapter 1, we mentioned that the TCP/IP suite, unlike the OSI model, has no session layer. But an application-layer protocol can include some of the features defined in this layer if needed. Does...

Are the HELO and MAIL FROM commands both necessary in SMTP? Why or why not?

Both HTTP and FTP can retrieve a file from a server. Which protocol should we use to download a file?

Using RFC 1939, assume a POP3 client is in the download-and-keep mode. Show the transaction between the client and the server if the client has only two messages of 192 and 300 bytes to download from...

Can we have a control connection without a data-transfer connection in FTP? Explain.

Does FTP have a message format for exchanging files or a list of directories/files during the file-transfer connection?

Does FTP have a message format for exchanging commands and responses during control connection?

Encode the following message in quoted-printable: 01001111 10101111 01110001

FTP can transfer files between two hosts using different operating systems with different file formats. What is the reason?

In FTP, can a server get the list of the files or directories from the client?

In FTP, can a server retrieve a file from the client site?

In SMTP, a sender sends unformatted text. Show the MIME header.

In FTP, which entity (client or server) starts (actively opens) the control connection? Which entity starts (actively opens) the data transfer connection?

FTP uses the services of TCP for exchanging control information and data transfer. Could FTP have used the services of UDP for either of these two connections? Explain.

In Chapter 1, we mentioned that the TCP/IP suite, unlike the OSI model, has no session layer. But an application-layer protocol can include some of the features defined in this layer if needed. Does...

In SMTP, a. a non-ASCII message of 1000 bytes is encoded using base64. How many bytes are in the encoded message? How many bytes are redundant? What is the ratio of redundant bytes to the total...

FTP uses two separate well-known port numbers for control and data connection. Does this mean that two separate TCP connections are created for exchanging control information and data?

When an HTTP server receives a request message from an HTTP client, how does the server know when all headers have arrived and the body of the message is to follow?

Alice has a video clip that Bob is interested in getting; Bob has another video clip that Alice is interested in getting. Bob creates a web page and runs an HTTP server. How can Alice get Bobs clip?...

In HTTP, draw a figure to show the application of cookies in a scenario in which the server allows only the registered customer to access the server.

We have input stream classes in Java. Can you explain why the TCP client program does not directly use these classes to create the input stream?

What is the difference between the Data gram Socket class and the Socket class in Java?

Write a statement in Java to extract the port number of an InetSocketAddress named sockAd.

Write a statement in Java to extract the InetAddress of an InetSocketAddress named sockAd.

In Figure 25.15, assume that the request is a URL to retrieve a picture. How is the URL stored in the recvBuff? Figure 25.15 Figure 25.15 Design of the UDP server Server application program Process...

In Figure 25.16, what changes are needed if a client needs to send a message other than a string (a picture, for example). Figure 25.16 Figure 25.16 Design of the UDP Client Client application...

Write a statement in Java to create a socket address bound to the host with domain name some.com and a client process with port number 51000.

Write a statement in Java to create a socket address bound to the local host and the ephemeral port number 56000.

A socket address is the combination of an IP address and a port number that defines an application program running on a host. Can we create an instance of the InetSocketAddress class with an IP...

Write a statement in Java that stores the port number 62230 in a variable in Java and guarantees that the number is stored as an unsigned number.

You want to write a program in which you need to refer to the InetAddress of the computer you are working with. Write a statement in Java to create the corresponding object.

You think that a computer with the IP address 14.26.89.101 has more IP addresses. Write a statement in Java to create an array of InetAddress classes associated with this host.

Assume that we make an enhancement to a computer that improves some mode of execution by a factor of 10. Enhanced mode is used 50% of the time, measured as a percentage of the execution time when the...

Create the relational diagram. Use the database shown in Figure P3.24 to answer this Problem. ROBCOR is an aircraft charter company that supplies on-demand charter flight services using a fleet of...

Using your schools student information system, print your class schedule. The schedule probably would contain the student identification number, student name, class code, class name, class credit...

Write the relational algebra formula to apply a UNION relational operator to the tables shown in Figure Q3.13. Figure Q3.13: Database name: Ch03_VendingCo Table name: MACHINE MACHINE_PRODUCT...

What are the three types of results a subquery can return?