Week 3 The Transport and Application Layer - The Bits and Bytes of Computer Networking - Google IT Support

Sequence numbers Sequence numbers allow the data to be put back together in the correct order.

A communication sent through Transmission Control Protocol (TCP) arrives out of order. What allows the data to be put back together in the correct order? Checksum Preamble Acknowledgement number Sequence numbers

CLOSED The TCP socket will be in the CLOSED state when the connection has been fully terminated and no further communication is possible.

A connection has been terminated and no communication is possible. What is the Transmission Control Protocol (TCP) socket state? CLOSED FIN_WAIT CLOSE_WAIT FINISHED

seven Unlike our model, which focuses on five layers, the OSI model has seven layers.

The OSI network model has _____ layers. three five six seven

The data will be discarded. At the IP or ethernet level, if a checksum doesn't compute, all of the data is just discarded. It's up to TCP to determine when to resend this data.

The checksum doesn't compute for a packet sent at the Internet Protocol (IP) level. What will happen to the data? The data will be discarded. It will be sent, but may be out of order. The data will be sent back to the sending node with an error. The data will be resent.

demultiplexing Demultiplexing allows traffic intended for many different services to be delivered to the same node.

The concept of taking traffic that's all aimed at the same node and delivering it to the proper receiving service is known as _________. multiplexing demultiplexing routing encapsulation

Four-way handshake A four-way handshake occurs when the session is closed.

A device involved in a Transmission Control Protocol (TCP) connection is ready to close the connection. The other device in the connection agrees. What has occured? Two-way handshake Handshake Three-way handshake Four-way handshake

10.1.1.150:80 The socket address will be 10.1.1.150:80. Unencrypted web traffic uses port 80 and ports are normally denoted with a colon after the IP address.

A user requests an unencrypted webpage from a web server running on a computer, listening on the Internet Protocol address 10.1.1.150. What will be the socket address? 10.1.1.150:21 10.1.1.150.80 10.1.1.150.21 10.1.1.150:80

application There are lots of application layer protocols, but HTTP is one of the most common ones.

HTTP is an example of a(n) ______ layer protocol. transport data-link application network

6

How many Transmission Control Protocol (TCP) control flags are there? 5 7 6 8

6 6 bits are reserved for the 6 TCP control flags.

How many bits are reserved for the Transmission Control Protocol (TCP) flags? 10 6 8 4

LISTEN The LISTEN state means that a port is waiting for something to connect to it.

If a TCP socket is ready and listening for incoming connections, it's in the ______ state. ESTABLISHED CLOSE_WAIT SYN_SENT LISTEN

PSH The PSH flag ensures that the receiving end doesn't wait for any further data.

If the transmitting device would like for the receiving device to push currently buffered data to the application on the receiving end immediately, it would set the ____ flag. SYN ACK PSH FIN

Source port A source port is a high-numbered port chosen from a special section of ports known as ephemeral ports.

Which field in a Transmission Control Protocol (TCP) header is chosen from ephemeral ports? Destination port Source port Sequence number Acknowledgement number

PSH The PSH flag will be used to push the information immediately.

You are sending a very small amount of information that you need the listening program to respond to immediately. Which Transmission Control Protocol (TCP) flag will be used? PSH RST URG ACK