The Transport and Application Layers

Question 1

One of the TCP control flags. Short for acknowledge. A value of one in this field means that the acknowledgement number field should be examined

Answer 1

ACK FLAG

Question 2

The number of the next expected segment in a TCP sequence

Answer 2

ACKNOWLEDGEMENT NUMBER

Question 3

The layer that allows network applications to communicate in a way they understand

Answer 3

APPLICATION LAYER

Question 4

The entire contents of whatever data applications want to send to each other

Answer 4

APPLICATION LAYER PAYLOAD

Question 5

A connection state that indicates that the connection has been fully terminated, and that no further communication is possible

Answer 5

CLOSE

Question 6

A connection state that indicates that the connection has been closed at the TCP layer, but that the application that opened the socket hasn’t released its hold on the socket yet

Answer 6

CLOSE_WAIT

Question 7

A data-transmission protocol that establishes a connection at the transport layer, and uses this to ensure that all data has been properly transmitted

Answer 7

CONNECTION-ORIENTED PROTOCOL

Question 8

A data-transmission protocol that allows data to be exchanged without an established connection at the transport layer. The most common of these is known as UDP or User Datagram Protocol

Answer 8

CONNECTIONLESS PROTOCOL

Question 9

The number of the next expected segment in a TCP packet/datagram

Answer 9

DATA OFFSET FIELD

Question 10

Taking traffic that’s all aimed at the same node and delivering it to the proper receiving service

Answer 10

DEMULTIPLEXING

Question 11

The port of the service the TCP packet is intended for

Answer 11

DESTINATION PORT

Question 12

Status indicating that the TCP connection is in working order, and both sides are free to send each other data

Answer 12

ESTABLISHED

Question 13

One of the TCP control flags. Short for finish. When this flag is set to one, it means the transmitting computer doesn’t have any more data to send and the connection can be closed

Answer 13

FIN

Question 14

A TCP socket state indicating that a FIN has been sent, but the corresponding ACK from the other end hasn’t been received yet.

Answer 14

FIN_WAIT

Question 15

A device that blocks or allows traffic based on established rules

Answer 15

FIREWALL

Question 16

An older method used for transferring files from one computer to another, but you still see it in use today

Answer 16

FTP

Question 17

A way for two devices to ensure that they’re speaking the same protocol and will be able to understand each other

Answer 17

HANDSHAKE

Question 18

The actual implementation of something defined elsewhere

Answer 18

INSTANTIATION

Question 19

It means that a TCP socket is ready and listening for incoming connections

Answer 19

LISTEN

Question 20

It meant that nodes on the network have the ability to direct traffic toward many different receiving services

Answer 20

MULTIPLEXING

Question 21

It is sometimes used for more complicated flow control protocols

Answer 21

OPTIONS FIELD

Question 22

A 16-bit number that’s used to direct traffic to specific services running on a network computer

Answer 22

PORT

Question 23

It is responsible for making sure that the unencapsulated application layer data is actually able to be understood by the application in question

Answer 23

PRESENTATION LAYER

Question 24

A TCP control flag short for push. this flag meant that the transmitting device whats the receiving device to push currently-buffered data to the application on the receiving end as soon as possible

Answer 24

PSH FLAG

Question 25

A TCP control flag short for reset. This flag means that one of the sides in a TCP connection hasn’t been able to properly recover from a series of missing or malformed segments

Answer 25

RST FLAG

Question 26

A 32-bit number that’s used to keep track of where in a sequence of TCP segments this one is expected to be

Answer 26

SEQUENCE NUMBER

Question 27

A program running on a computer waiting to be asked for data

Answer 27

SERVER or SERVICE

Question 28

The network layer responsible for facilitating the communication between actual applications and the transport layer

Answer 28

SESSION LAYER

Question 29

The instantiation of an endpoint in a potential TCP connection

Question 30

The instantiation of an endpoint in a potential TCP connection

Answer 30

SOCKET

Question 31

A high numbered port chosen from a special section of ports known as ephemeral ports

Answer 31

SOURCE PORT

Question 32

A TCP flag that stands for synchronize. This flag is used when first establishing a TCP connection and make sure the receiving end knows to examine the sequence number field

Answer 32

SYN FLAG

Question 33

A TCP socket state that means that a socket previously in a listener state, has received a synchronization request and sent a SYN_ACK back

Answer 33

SYN_RECEIVED

Question 34

A TCP socket state that means that a synchronization request has been sent, but the connection hasn’t been established yet

Answer 34

SYN_SENT

Question 35

A mechanism that makes sure that no data is lost or corrupted during a transfer

Answer 35

TCP CHECKSUM

Question 36

A payload section of an IP datagram made up of a TCP header and a data section

Answer 36

TCP SEGMENT

Question 37

The range of sequence numbers that might be sent before an acknowledgement is required

Answer 37

TCP WINDOW

Question 38

A TCP control flag short for urgent. A value of one here indicates that the segment is considered urgent and that the urgent pointer field has more data about this

Answer 38

URG FLAG

Question 39

A field used in conjunction with one of the TCP control flags to point out particular segments that might be more important than others

Answer 39

URGENT POINTER FIELD