• Network:

A computer network or data network is a telecommunications network that allows computers to exchange data.

In computer networks, networked computing devices pass data to each other along data connections.

The connections (network links) between nodes are established using either cable media or wireless media.

The best-known computer network is the Internet.

 

• Internetwork:

Internetworking is the practice of connecting a computer network with other networks through the use of gateways that provide a common method of routing information packets between the networks.

The resulting system of interconnected networks is called an internetwork, or simply an internet.

Internetworking is a combination of the words inter (“between”) and networking; not internet-working or international-network.

 

• Intra Network:

An intranet is a computer network that uses Internet Protocol technology to share information, operational systems, or computing services within an organization.

This term is used in contrast to extranet, a network between organizations, and instead refers to a network within an organization.

Sometimes, the term refers only to the organization’s internal website, but may be a more extensive part of the organization’s information technology infrastructure, and may be composed of multiple local area networks.

The objective is to organize each individual’s desktop with minimal cost, time and effort to be more productive, cost efficient, timely, and competitive.

 

• Extranet:

An extranet is a computer network that allows controlled access from the outside, for specific business or educational purposes.

In a business-to-business context, an extranet can be viewed as an extension of an organization’s intranet that is extended to users outside the organization, usually partners, vendors and suppliers, in isolation from all other Internet users.

In contrast, business-to-consumer (B2C) models involve known servers of one or more companies, communicating with previously unknown consumer users.

 An extranet is similar to a DMZ in that it provides access to needed services for channel partners, without granting access to an organization’s entire network.

 

 

• Topology:

Topology means structure of Network.

Types of Networks:

1. Single Node Topology

2. Bus Topology

• Easiest network topology for connecting computers or peripherals in a linear fashion.
• Requires less cable length than a star topology.
• It works well when you have a small network.

  3. Ring Topology

  

• A network server is not needed to control network connectivity between each workstation.
• All data flows in one direction, reducing the chance of packet collisions.
• Data can transfer between workstations at high speeds.
• Additional workstations can be added without impacting performance of the network.

4. Star Topology

   

• As compared to Bus topology it gives far much better performance, signals don’t necessarily get transmitted to all the workstations. A sent signal reaches the intended destination after passing through no more than 3-4 devices and 2-3 links.
• Performance of the network is dependent on the capacity of central hub.
• Easy to connect new nodes or devices. In star topology new nodes can be added easily without affecting rest of the network. Similarly components can also be removed easily.
•  Centralized management. It helps in monitoring the network.
   Failure of one node or link doesn’t affect the rest of network. At the same time its easy to detect the failure and troubleshoot it.

 

5. Mesh Topology

   

   1) Data can be transmitted from different devices simultaneously. This topology can withstand high traffic.
   2) Even if one of the components fails there is always an alternative present. So data transfer doesn’t get affected.
   3) Expansion and modification in topology can be done without disrupting other nodes.

 

6. Hybrid Topology

   

• Hybrid, as the name suggests, is mixture of two different things.
• Similarly in this type of topology we integrate two or more different topologies to form a resultant topology which has good points(as well as weaknesses) of all the constituent basic topologies rather than having characteristics of one specific topology.
• This combination of topologies is done according to the requirements of the organization.

 

7. Tree Topology

   

• A tree topology is a special type of structure in which many connected elements are arranged like the branches of a tree. For example, tree topologies are frequently used to organize the computers in a corporate network, or the information in a database.
• In a tree topology, there can be only one connection between any two connected nodes. Because any two nodes can have only one mutual connection, tree topologies form a natural parent-child hierarchy.

 

• Network Device:

Equipment’s that connect directly to a network segment is referred to a device.

These devices are broken up into two classification:

1. End-User Device

These are the device that include computer, printer, scanner, and other device that provides service directly to user.

 

2. Network Device

These are the device that include all device that connects end-user device together to allow them to communicate.

 

To connect same device (Cross Crimping):

Eg: Hub to Hub or Switch to Switch.

 

Orange white                                       Green white

Orange                                                  Green

Blue white                                            Blue white

Green                                                    Orange

Green white                                         Orange white

Blue                                                        Blue

Brown white                                         Brown white

Brown                                                    Brown

 

 

To connect different device (straight crimping):

Eg: Hub to PC or switch to PC

 

Orange white                                        Orange white

Orange                                                    Orange

Blue white                                              Blue white

Green                                                      Green

Green white                                          Green white

Blue                                                        Blue

Brown white                                        Brown white

Brown                                                    Brown