Chapter 9 Exam

Which transport layer feature is used to guarantee session establishment? 1. UDP ACK flag 2. TCP 3-way handshake 3. UDP sequence number 4. TCP port number

2

A PC is downloading a large file from a server. The TCP window is 1000 bytes. The server is sending the file using 100-byte segments. How many segments will the server send before it requires an acknowledgment from the PC? 1. 10 segments 2. 1000 segments 3. 100 segments 4. 1 segment

1

During a TCP session, a destination device sends an acknowledgment number to the source device. What does the acknowledgment number represent? 1. The next byte that the destination expects to receive 2. The total number of bytes that have been received 3. The last sequence number that was sent by the source 4. One number more than the sequence number

1

Network congestion has resulted in the source learning of the loss of TCP segments that were sent to the destination. What is one way that the TCP protocol addresses this? 1. The source decreasses the amount of data that it transmits before it receives an acknowledgement from the destination. 2. The source decreases the windows size to decrease the rate of transmission from the destination 3. The destination decreases the window size. 4. The destination sends fewer acknowledgement messages in orded to conserve bandwidth

1

What OSI layer is responsible for a temporary communication session between two applications and ensuring that transmitted data can be reassembled in proper sequence? 1. Transport 2. Network 3. Data link 4. Session

1

What does a client do when it has UDP datagrams to send? 1. It just sends the datagram. 2. It sends a simplified three-way handshake to the server. 3. It sends to the server a segment with the SYN flag set to synchronize the conversation. 4. It queries the server to see if it is ready to receive data

1

What is an advantage of UDP over TCP? 1. UDP communication requires less overhead. 2. UDP communication is more reliable. 3. UDP reorders segments that are received out of order. 4. UDP acknowledges received data

1

What type of applications are best suited for using UDP? 1. Applications that are sensitive to delay 2. Applications that need reliable delivery 3. Applications that require retransmission of lost segments 4. Applications that are sensitive to packet loss

1

What are three responsibilities of the transport layer? (Choose three.) 1. Meeting the reliability requirements of applications, if any 2. Multiplexing multiple communication streams from many users or applications on the same network 3. Idemtifying the applications and services on the client and server that should handle transmitted data 4. Directing packets towards the destination network 5. Formatting data into a compatible form for receipt by the destination devices 6. Conducting error detection of the contents in frames

1, 2, 3

Which three application layer protocols use TCP? (Choose three.) 1. FTP 2. DHCP 3. TFTP 4. SMTP 5. HTTP 6. SNMP

1, 4, 5

Which two flags in the TCP header are used in a TCP three-way handshake to establish connectivity between two network devices? (Choose two.) 1. ACK 2. RST 3. FIN 4. URG 5. PSH 6. SYN

1, 6

A client application needs to terminate a TCP communication session with a server. Place the termination process steps in the order that they will occur. (Not all options are used.) 1. Step 1 2. Step 2 3. Step 3 4. Step 4 a. server sends SYN b. client sends ACK c. server sends FIN d. client sends FIN e. server sends ACK f. client sends SYN

1-d, 2-e, 3-c, 4-b

A host device is receiving live streaming video. How does the devise account for video data that is lost during transmission? 1. The device will use sequence numbers to pause the video stream untill the correct data arrives. 2. The device will continue receiving the streaming video, but there may be a momentary disruption. 3. The device will delay the streaming video untill the entire video stream is received. 4. The device will immediately request a retransmission of the missing data.

2

A host device needs to send a large video file across the network while providing data communication to other users. Which feature will allow different communication streams to occur at the same time, without having a single data stream using all available bandwidth? 1. Port numbers 2. Multiplexing 3. Window size 4. Acknowledgments

2

What happens if part of an FTP message is not delivered to the destination? 1. The message is lost because FTP does not use a reliable delivery method. 2. The part of the FTP message that was lost is re-sent. 3. The entire FTP message is re-sent. 4. The FTP source host sends a query to the destination host.

2

What is a socket? 1. The combination of the source and destination sequence numbers and port numbers. 2. The combination of s source IP address and port number or destination IP address and port number. 3. The combination of the source and destination sequence and acknowledgment numbers. 4. The combination of the source and destination IP address and source and destination Ethernet address

2

What is the purpose of the TCP sliding window? 1. To inform a source to retransmit data from a specific point forward 2. To request that a source decrease the rate at which it transmits data 3. To end communication when data transmission is complete 4. To ensure that segments arrive in order at the destination

2

What three fields are used in a UDP segment header? (Choose three.) 1. Window Size 2. Length 3. Source Port 4. Acknowledgement Number 5. Checksum 6. Sequence Number

2, 3, 5

Which two characteristics are associated with UDP sessions? (Choose two.) 1. Transmitted data segments are tracked. 2. Destination devices receive traffic with minimal delay. 3. Unacknowledged data packets are retransmitted. 4. Received data is unacknowledged. 5. Destination devices reassemble messages and pass them to an application

2, 4

Which two services or protocols use the preferred UDP protocol for fast transmission and low overhead? (Choose two) 1. FTP 2. DNS 3. HTTP 4. POP3 5. VoIP

2, 5

What does the value of the window size specify? 1. The amount of data that can be sent at one time 2. The total number of bits received during this TCP session 3. The amount of data that can be sent sefore an acknowledgement is required 4. A random number that is used in establishing a connection with the 3-way handshake

3

What happens if the first packet of a TFTP transfer is lost? 1. The next-hop router or the default gateway will provide a reply with an error code. 2. The client will wait indefinitely for the reply. 3. The TFTP application will retry the request if a reply is not received. 4. The transport layer will retry the query if a reply is not received

3

What is a characteristic of UDP? 1. Applications that use UDP are always considered unreliable. 2. UDP datagrams take the same path and arrive in the correct order at the destination. 3. UDP reassembles the received datagrams in the order they were received. 4. UDP only passes data to the network when the destination is ready to receive the data

3

What is a characteristic of a TCP server process? 1. A host running two different applications can have both configured to use a dynamic port number. 2. Every application process running on the server has to be configured to use a dynamic port number. 3. There can be many ports open simultaneously on a server, one for each active server application. 4. An individual server can have two services assigned to the same port number within the same transport layer services

3

What is the complete range of TCP and UDP well-known ports? 1. 256-1023 2. 1024-49151 3. 0 to 1023 4. 0 to 255

3

What is the purpose of using a source port number in a TCP communication? 1. To notify the remote device that the conversation is over 2. To assemble the segments that arrived out of order 3. To keep track of multiple conversations between devices 4. To inquire for a nonreceived segment

3

What kind of port must be requested from IANA in order to be used with a specific application? 1. Dynamic port 2. Source port 3. Registered port 4. Private port

3

What type of information is included in the transport header? 1. Destination and source logical addresses 2. Encoded application data 3. Destination and source port numbers 4. Destination and source physical addresses

3

When is UDP preferred to TCP? 1. When all the data must be fully received before any part of it is considered useful 2. When a client sends a segment to a server 3. When an application can tolerate some loss of data during transmission 4. When segments must arrive in a very specific sequence to be processed successfully

3

Which action is performed by a client when establishing communication with a server via the use of UDP at the transport layer? 1. The client sets the window size for the session. 2. The client sends an ISN to the server to start the 3-way handshake. 3. The client randomly selects a source port number. 4. The client sends a synchronization segment to begin the session

3

Which flag in the TCP header is used in response to a received FIN in order to terminate connectivity between two network devices? 1. RST 2. FIN 3. ACK 4. SYN

3

Which number or set of numbers represents a socket? 1. 01-23-45-67-89-AB 2. 21 3. 192.168.1.1:80 4. 10.1.1.15

3

What does TCP do if the sending source detects network congestion on the path to the destination? 1. The source will acknowledge the last segment that is sent and include a request for a smaller window size in the message. 2. The source host will send a request for more frequent acknowledgments to the destination. 3. The destination will request retransmission of the entire message. 4. The source will decrease the amount of data that it sends before it must receive acknowledgements from the destination

4

What information is used by TCP to reassemble and reorder received segments? 1. Acknowledge numbers 2. Fragment numbers 3. Port numbers 4. Sequence numbers

4

Which factor determines TCP window size? 1. The number of services included in the TCP segment 2. The amount of data to be transmitted 3. The amount of data the source is capable of sending at one time 4. The amount of data the destination can process at one time

4

Why does HTTP use TCP as the transport layer protocol? 1. Because transmission errors can be tolerated easily 2. To ensure the fastest possible download speed 3. Because HTTP is a best-effort protocol 4. Because HTTP requires reliable delivery

4