CND1/Ch2: The TCP/IP & OSI Networking Models

Question 1

(Concept) The two computers use a protocol to communicate with the same layer on another computer

Answer 1

Same layer interaction on different computers

Question 2

(Concept) On a single computer, one layer provides a service to a higher layer

Answer 2

Adjacent layer interaction on the same computer

Question 3

(OSI layer) Interfaces between network and application software. Also includes authentication services

Answer 3

Application (7)

Question 4

(OSI layer) Defines the format and organization of data. Includes encryption

Answer 4

Presentation (6)

Question 5

(OSI layer) Establishes and maintains end-to-end bidirectional flows between endpoints. Includes managing transaction flows

Answer 5

Session (5)

Question 6

(OSI layer) Provides a variety of services between two host computers, including connection establishment and termination, etc of large data blocks into smaller parts for transmission

Answer 6

Transport (4)

Question 7

(OSI layer) Logical addressing, routing, and path determination

Answer 7

Network (3)

Question 8

(OSI layer) Formats data into frames appropriate for transmission onto some physical medium. Defines rules for when the medium can be used. Defines means by which to recognize transmission errors

Answer 8

Data link (2)

Question 9

(OSI layer) Defines the electrical, optical, cabling, etc required for transmitting bits, represented as some form of energy passing over a physical medium

Answer 9

Physical (1)

Question 10

(Definition)
The general topic of how on one computer, two adjacent layers in a networking architectural model work together, with the lower layer providing services to the higher layer

Answer 10

adjacent-layer interaction

Question 11

(Definition)
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 11

decapsulation

Question 12

(Definition)
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.

Answer 12

encapsulation

ex. IP packet could be encapsulated in an Ethernet header and trailer before being sent over an Ethernet

Question 13

(Definition)

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

Answer 13

frame

Question 14

(Definition)
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

Answer 14

networking model

ex. TCP/IP and OSI

Question 15

(Definition)
A logical grouping of info that includes the network layer header and encapsulated data, but specifically does not include any headers and trailers below the network layer

Answer 15

packet

Question 16

(Definition)
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 16

protocol data unit (PDU)

Question 17

(Definition)
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.

Answer 17

same-layer interaction