Alex Leifheit

NETWORKS

NETWORK• A number of interconnected computers, machines, or operations.

Key Components

• Network components, Network Architecture, Types of Network, Firewalls, IP addresses , internet, Web 2.0.

TYPES OF NETWORKS• There are 4 main types of networks PAN,MAN,LAN and WAN.

PAN

Personal Area Network – Short range network between a computer and a mobile phone or similar portable device.

MAN

Metropolitan Area Network – Computer network over a large area such as a city.

LAN

Local Area Network - computer network in a small area such as an office building.

WAN

Wide area Network – Computer network of a large area such as a country or several countries.

NETWORK COMPONENTS • There are three parts to a network components Hubs, Switches, and Routers.

• Packet – unit of data that is routed between origin and a destination on the internet.

Hubs

A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN(local area network). When a packet arrives at one port, it is copied to other ports so that all segments of the LAN can see all the packets. A hub contains multiple ports.

Switches

A computer networking device that connects devices together on a computer network by using packet switching to receive, process and forward data to the destination device. Device switches support any packet protocol. Ultimately it’s a Hardware device for connecting several computers on a network that receives data from a hub and determines where it goes from their.

Routers

A router is a device that forwards data packets along networks. A router is connected to at least two networks commonly two LANs or WANs(wide area network). Routers use headers and fowarding tables to determine the best pathway for forwarding the packets.

HUBS

SWITCHES

ROUTER

FIREWALL • A software or hardware used to control data entering and leaving a network.

Network Architecture

IP ADDRESSES• Unique address assigned to every computer on a network. It’s a 32 –bit number which is

called a dotted decimal. There are also public and private IP addresses.

Public

Registered with the NIC(network information center) to avoid address conflicts. Devices that need to be publicly identified such as web or mail servers must have a globally unique IP address, and they are assigned a public IP address.

Private

Devices that do not require public access are given Private IP Address this prohibits anyone from identifying personal information. Common uses for a Private IP address are for Printers, and much more.

THE INTERNET • The global communication network that allows almost all computer worldwide to connect

and exchange information. Networks connect to the internet.

WEB 2.0 • Describes the World Wide Web sites that emphasize user generated content, usability,

and interoperability.

• Web 2.0 sites allow users to interact and collaborate with each other.

- Social media, Blogs, Wikis, hosted services

SYNCHRONOUS OR ASYNCHRONOUS• Data transfer between computers can occur either synchronously or asynchronously .In

Asynchronous transfer the sender and receiver are not synchronized in terms of time. Asynchronous transfer, the sender and receiver synchronize times and agree on a transfer rate before the start of the transfer.

PEER TO PEER • On a peer to peer network every client has equal status and there id no central authority

or server.

CACHING• A process used to speed up activities such as web browsing.

INTERNET PROTOCOLS• Hypertext Transfer Protocol (htttp) is the protocol that governs communication between

web servers and web browsers.