Module 14 - Transport Layer

Which two operations are provided by TCP but not by UDP? - Acknowledging received data - Retransmitting any unacknowledged data - Reconstructing data in the order it was received - Identifying the applications - Identifying individual conversations

- Acknowledging received data - Retransmitting any unacknowledged data

Which three are transport layer responsibilities? (Choose three.) - Conversation Multiplexing - Identifying Frames - Identifying Routing Information - Segmenting Data and Reassembling Segments - Tracking Individual Conversations

- Conversation Multiplexing - Segmenting Data and Reassembling Segments - Tracking Individual Conversations

Which two services or protocols use the preferred UDP protocol for fast transmission and low overhead? - FTP - DNS - HTTP - POP3 - VoIP

- DNS - VoIP

Which two fields are the same in a TCP and UDP header?

- Destination Port Number - Source Port Number

Which two applications would use the TCP transport layer protocol? - FTP - HTTP - ICMP - TFTP - VoIP

- FTP - HTTP

Which two flags in the TCP header are used in a TCP three-way handshake to establish connectivity between two network devices? - SYN - PSH - URG - RST - FIN - ACK

- SYN - ACK

Which two applications would use UDP transport layer protocol? - FTP - HTTP - ICMP - TFTP - VoIP

- TFTP - VoIP

What is the complete range of TCP and UDP well-known ports?

0 to 1023

Assume a host with IP address 10.1.1.10 wants to request web services from a server at 10.1.1.254. Which of the following would display the correct socket pair? - 1099:10.1.1.10, 80:10.1.1.254 - 10.1.1.10:80, 10.1.1.254:1099 - 10.1.1.10:1099, 10.1.1.254:80 - 80:10.1.1.10, 1099:10.1.1.254

10.1.1.10:1099, 10.1.1.254:80

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

192.168.1.1:80

What type of applications are best suited for using UDP?

Applications that are sensitive to delay

How does a networked server manage requests from multiple clients for different services?

Each request has a combination of source and destination port numbers, coming form a unique IP address.

How many exchanges are needed to end both sessions between two hosts?

Four Exchanges

Which TCP header statement is true? - It consists of 4 fields in an 8-byte header. - It consists of 8 fields in a 10-byte header. - It consists of 10 fields in a 20-byte header. - It consists of 20 fields in a 40-byte header.

It consists of 10 fields in a 20-byte header.

Which UDP header statement is true? - It consists of 4 fields in an 8-byte header. - It consists of 8 fields in a 10-byte header. - It consists of 10 fields in a 20-byte header. - It consists of 20 fields in a 40-byte header.

It consists of 4 fields in an 8-byte header.

Why is UDP desirable for protocols that make a simple request and reply transactions?

Low Overhead

Which control bit flags are used during the three-way handshake?

SYN and ACK

What field is used by the destination host to resassmeble segments into the original order?

Sequence Number

What TCP mechanism is used to enhance performance by allowing a device to continuously send a steady stream of segments as long as the device is also receiving necessary acknowledgements?

Sliding window

Which of the following would be valid source and destination ports for a host connecting to an email server? - Source: 25, Destination: 49152 - Source: 80, Destination: 49152 - Source: 49152, Destination: 25 - Source: 49152, Destination: 80

Source: 49152, Destination: 25

Which of the following would be valid source and destination ports for a host connecting to a DNS server? - Source: 53, Destination: 49152 - Source: 1812, Destination: 49152 - Source 49152, Destination: 53 - Source: 49152, Destination 1812

Source: 49152, Destination: 53

Which transport layer protocol ensures reliable same-order delivery?

TCP

Which transport layer feature is used to establish a connection-oriented session?

TCP 3-Way Handshake

Which action performed by a client when establishing communication with a server via the use of UDP at the transport layer?

The client randomly selects a source port number.

What is a socket?

The combination of a source IP address and port number or a destination IP address and port number.

What happens if part of an FTP message is not delivered to the destination?

The part of the FTP message that was lost is re-sent.

What happens when a sending host senses there is congestion?

The sending host reduces the number of bytes it sends before receiving an acknowledgment from the destination host.

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?

The source decreases the amount of data that is transmits before it receives an acknowledgment from the destination.

What is the purpose of using a source port number in a TCP communication?

To keep track of multiple conversations between devices

What is the responsibility of transport layer protocols?

Tracking individual conversations

Which layer is responsible for establishing a temporary communication session between the source and destination host applications?

Transport Layer

Which of the following is a stateless best-effort delivery transportation layer protocol? - ICMP - IP - TCP - UDP

UDP

Which transport layer protocol statement is true? - TCP has fewer fields than UDP. - TCP is faster than UDP. - UDP is a best-effort delivery protocol. - UDP provides reliability.

UDP is a best-effort delivery protocol.

Which UDP datagram reassembly statement is true? - UDP does not reassemble the data. - UDP reassembles the data in the order that it was received. - UDP reassembles the data using control bits. - UDP resassembles the data using sequence numbers.

UDP reassembles the data in the order that it was received.

Which transport layer protocol would be used for VoIP applications?

User Datagram Protocol (UDP)

Which port group includes port numbers for FTP, HTTP, and TFTP applications?

Well-known ports

What field is used to provide flow control?

Window Size

Which Windows command would display the protocols in use, the local address and port numbers, the foreign address and port numbers, and the connection state?

netstat