Chapter 14 - check your understanding
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?
10.1.1.10:1099, 10.1.1.254:80
Which number or set of numbers represents a socket?
192.168.1.1:80
Which two flags in the TCP header are used in a TCP three-way handshake to establish connectivity between two network devices? (Choose two.)
ACK and SYN
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 from a unique IP address.
Which two applications would use the TCP transport layer protocol? (Choose two.)
FTP HTTP
Which TCP header statement is true?
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
Which control bit flags are used during the three-way handshake?
SYN and ACK
What field is used by the destination host to reassemble segments into the original order?
Sequence Number
Which of the following would be valid source and destination ports for a host connecting to an email server?
Source: 49152, Destination: 25
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 two applications would use the UDP transport layer protocol? (Choose two.)
TFTP and VoIP
Which action is 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 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.
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 it transmits before it receives an acknowledgement from the destination.
Which of the following is a stateless best-effort delivery transport layer protocol?
UDP
Which transport layer protocol statement is true?
UDP is a best-effort delivery protocol
Which UDP datagram reassembly statement is true?
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 two services or protocols use the preferred UDP protocol for fast transmission and low overhead? (Choose two)
VoIP and DNS
What happens when a sending host senses there is congestion?
When a sending host senses congestion, it reduces the number of bytes it sends before receiving an acknowledgment from the destination host.
What type of applications are best suited for using UDP?
applications that are sensitive to delay
Which three are transport layer responsibilities? (Choose three.)
conversation multiplexing* tracking individual conversations* segmenting data and reassembling segments*
How many exchanges are needed to end both sessions between two hosts?
four exchanges
Why is UDP desirable for protocols that make a simple request and reply transactions?
low overhead
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 or netstat -n
Which two operations are provided by TCP but not by UDP? (Choose two.)
retransmitting any unacknowledged data* acknowledging received data*
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 two fields are the same in a TCP and UDP header? (Choose two.)
source port number destination port number
Which of the following would be valid source and destination ports for a host connecting to a DNS server?
source: 49,512 , destination: 53
What is a socket?
the combination of a source IP address and port number or a destination IP address and port number
What is the purpose of using a source port number in a TCP communication?
to keep track of multiple conversations between devices
What is a 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 port group includes port numbers for FTP, HTTP, and TFTP applications?
well-known ports
What field is used to provide flow control?
window size
