Cisco, Networking Essentials with complete verified solutions already graded A+

ISO

International Organization for Standardization

OSI

Open Systems Intercommunication

TCP/IP

Transmission Control Protocol/ Internet Protocol

Layers

Logical functions that are part of a communication process between two entities, usually, computer's

Interface

The way information is exchanged

Modular

Divided in modules

HTTP

Hypertext Transfer Protocol

HTML

Hypertext Markup Language

PDF

Portable Document Format

DNS

Domain Name System

FTP

File Transfer Protocol

SMTP

Simple Mail Transfer Protocol

OSI Layer 1

Phsical

OSI Layer 2

Data-Link

OSI Layer 3

Network

OSI Layer 4

Transport

OSI Layer 5

Session

OSI Layer 6

Presentation

OSI Layer 7

Application

TCP/IP Layer 1

Network Access

TCP/IP Layer 2

Internet

TCP/IP Layer 3

Transport = OSI Layer 4

TCP /IP Layer 4

Application = OSI Layer 7+6+5

OSI Session Layer 5

Manages the application on the source computer and the application on the destination computer.

OSI Transport Layer 4

Responsible for identifying the application to the destination computer by using port numbers

OSI Presentation Layer 6

Responsible for the manner in which the data from the Application Layer on the source device is presented (or represented) to the Application Layer on the destination device

OSI Application Layer 7

Where the encapsulation process begins. The information on this layer is specific to the service or application that is requesting information to be transferred to another device

Encryption

Scrambles the data so that it cannot be read if intercepted. Only the destination device can decrypt or read it.

Compression

Eliminates redundant information so that the data take up less space. When that data arrives to the destination , the redundant data is added back again.

Transport layer protocols

TCP - Transmission Control Protocol

UDP - User Datagram Protocol

Unicast

When a single source host is sending information to a single destination host, know as one-to-one.

Broadcast

When a single host is sending information to all the host on the network, one-to-many.

Multicast

When a single host is sending information to some, but not all of the hosts on the network, one-to-some .

UDP

User Datagram Protocol

OSI Network Layer 3

Is responsible for identifying the destination device by its logical identification, when using TCP/IP, is called an IP address

IP address

It's a number that uniquely differentiates a host from all the other devices on the network.

It's based on a numbering system that makes it possible for computer's and routers to identify whether the destination device is on a local network or a remote network.

OSI Data-Link Layer 2

Is responsible for converting the logical identifier ( in case of TCP/IP an IP address to a physical identifier . The specific type of identifier depends on the protocol in use.

MAC

Media Access Control

Identifier used on Ethernet

MAC

OSI Physical Layer 1

At the physical layer, the entire package including header, data and trailer will be converted into bits for transmission .