Notes from Mike Meyers book

Question 1

What does ISO stand for and why are they important?

Answer 1

• International Organization for Standardization

- Created the OSI (Open Systems Interconnect model) which was a prescriptive model.

Question 2

What are protocols?

Answer 2

-Sets of clearly defined rules, regulations, standards, and procedures that enable hardware and software manufacturers to make devices and applications that function properly at a particular level.

Question 3

Describe Layer 7 of the OSI model.

Answer 3

-Application layer: encryption, user authentication, code that enables network aware applications such as APIs.

Question 4

Describe Layer 6 of the OSI model.

Answer 4

-Presentation layer: conversion of data into formats readable by system. Data conversion.

Question 5

Describe Layer 5 of the OSI model.

Answer 5

-Session: connects applications to applications; initiates, accepts incoming sessions, opens and closes existing sessions. Netstat-a

Question 6

Describe Layer 4 of the OSI model.

Answer 6

-Transport: TCP: breaks data into packets and gives sequence #; initializes requests for packtes. Assembly/disassembly.

Question 7

Describe Layer 3 of the OSI model.

Answer 7

• Network: packets created and addressed. Internet protocl, dotted decimal.
• packet handed off to programs

Question 8

Describe Layer 2 of the OSI model.

Answer 8

• Data link: Creates and sends frames, NIC. Data link control: service.
• Logical link control, media access control.

Question 9

Describe Layer 1 of the OSI model.

Answer 9

-Physical: Cabling/hubs

Question 10

Describe a NIC.

Answer 10

-Network interface card: contains 48-bit value called media access control device.

Question 11

Describe a Mac address.

Answer 11

• IEEE assigns blocks of MAC addresses
• Organizationally Unique Identifier: first six digits.
• Device ID: last six digits

Question 12

What does logical link control do?

Answer 12

Talks to operating system, puts data into frames, creates CRC on frames, processes incoming frames, erases frames.

Question 13

What are network protocols?

Answer 13

Create unique identifiers and sets of communication rules.

Question 14

Describe the application layer of the TCI/IP model?

Answer 14

-equivalent of session, presentation, application; initiates, controls and disconnects.

Question 15

Describe the transport layer of the TCP/IP model.

Answer 15

equivalent of OSI Transper and session and application layers. Assembly, dissasembly, connection vs. connectionless. TCP segment.

Question 16

Describe the internet layer of the TCP/IP model.

Answer 16

IP packet layer, routers.

Question 17

Describe the Link/network inteface layer of the TCP/IP model.

Answer 17

equivalent of OSI layer 1 and 2.

Question 18

Describe POP?

Answer 18

connection oriented.

Question 19

Describe VOIP.

Answer 19

connectionless UDP