Chapter 1

Question 1

When 2 computers use a protocol to communicate with the same layer on another computer. The protocol defines a header that communicates what each computer wants to do.

Answer 1

Same-layer interaction on different computers.

Question 2

On a single computer, one lower layer provides a service to the layer just above. The software or hardware that implements the higher layer requests that the next lower layer perform the needed function.

Answer 2

Adjacent-layer interaction on the same computer.

Question 3

On a computer that receives data over a network, the process in which the device interprets the lower-layer headers and when finished with each header, removes the header, revealing the next-higher-layer PDU.

Answer 3

de-encapsulation

Question 4

The placement of data from a higher-layer protocol behind the header ( and in some cases, between a header and trailer) of the next-lower-layer protocol. For example, an IP packet could be encapsulated in an Ethernet header and trailer before being sent over an Ethernet.

Answer 4

encapsulation

Question 5

A term referring to a data-link header and trailer, plus the data encapsulated between the header and trailer.

Answer 5

frame

Question 6

A generic term referring to any set of protocols and standards collected into a comprehensive grouping that, when followed by the devices in a network, allows all the devices to communicate. Examples include TCP/IP and OSI

Answer 6

networking model

Question 7

A logical grouping of bytes that includes the network layer header and encapsulated data, but specifically does not include any headers and trailers below the network layer.

Answer 7

packet

Question 8

A generic term referring to the header defined by some layer of a networking model, and the data encapsulated by the header (and possibly trailer) of that layer, but specifically not including any lower-layer headers and trailers.

Answer 8

protocol data unit (PDU)

Question 9

The communication between two networking devices for the purposes of the functions defined at a particular layer of a networking model, with that communication happening by using a header defined by that layer of the model. The two devices set values in the header, send the header and encapsulated data, with the receiving devices interpreting the header to decide what action to take.

Answer 9

same-layer interaction

Question 10

In TCP, a term used to describe a TCP header and its encapsulated data (also called an L4PDU). Also in TCP, the process of accepting a large chunk of data from the application layer and breaking it into smaller pieces that fit into TCP segments. In Ethernet, a segment is either a single Ethernet cable or a single collision domain (no matter how many cables are used).

Answer 10

segment