NETWORK PROTOCOL & WHAT IS RFC's

 

NETWORK PROTOCOL

Network protocol define rules and convetions for communication between different devices, participating in a computer network

Almost all protocol used in the internet are common standerds define by RFC.

Examples of standards network protocol are TCP,UDP, IP, HTTP, TFTP,SSH,telnet ...etc..

TCP(transmission control protocol)

UDP(user datagram  protocol)

IP(internet protocol)

TFTP(trivial file transfer protocol)

HTTP( hypertext transfer protocol)

SSH(secure shell)

Device participating in network communication should about the common network protocol and communication according to the way, define by the network protocol.

To explain it more clearly, if you are using your browser to browser web page from a web server, you are using a protocol called HTTP . your computer must request web page from your server using HTTP and web browser must response back your computer using 

  

WHAT ARE RFCs

A RFC (request for comments) is a pure technical document published by the internet engineering Task forces. Request for comments are mainly used to develop a "standard" network protocol,a function of a network protocol or any features related with network 

communication.

Some RFCs  are information and others published internet standards. The finely version of the RFC become a standards and is published with a number. 

At  the early stages of network communication ,each vendor had their own proprietary  network communication protocols.Different protocol for the same purpose were a serious problem in heterogeneous network environment, consisting of devices and operating system from different vendors.

All standards    network  protocol  are defined as RFCs. Individuals many join the IETF working groups to  help draft and develop networking standards or network protocol.

More than 7000 RFCs are available 

Internet works,Intranet and Extranet

Internet works,  Intranet and Extranet 

INTERNET WORKS:

An internet work can be defined as two or more computer networks, which are connected together,using network routers.

Each network in an internet work has its own network address, which is different form other networks inside from other networks inside the internet works.Network address is used to identify the networks inside a internet works.

INTRANET AND EXTRANET

INTRANET:

An internet is privet network that is contained within an enterprise.It may consist of many interlinked local area networks and use any wide area networks and use any technologies for networks connectivity.The main purpose of internet is so share company information and computing resources    among employees.

EXTRANET:

An extranet can be viewed as part of day-to-day of a company internet that is extended to user outside the company like suppliers, vendors , partners, customers or other business associated.

Extranet is required for normal day-to-day business  activities.For example vendors billing &invoices,payment , Discounted price lists for partners etc...

CENTRALIZED and DISTRIBUTED Computer Network Model

Centralized and Distributed Computer Network Model

In centralized computer network model, the network resources are placed and managed from a main location. Centralized network model allows administrators to manage the resource centrally.The network server and other critical networks resource are located in a central location

in a secure and dedicated server room.

Centralized networks model provides following advantages to network and system administrators.

Centralized network model provide Network and system administrators   better access to network devices.

In centralized networks model provides can managed more easily.

Centralized network provides better networks security.

The main disadvantages is more work load of networks and system administrators and increased risk of communication failure due to a catastrophe in the center location.

In distribution network model, the network resources are placed and manged from different geographical location.Designated network and system administrators   manged the network resources in different location. These days most of the enterprises network model are distributed.

PEER TO PEER NETWORKS

A peer to peer networks has no dedicated server. Here in peer to  peer networks ,a numbers of workstation are connected together for the purpose of sharing devices, information or data. All the workstation are considered as equal. Any one computer can act as client act as or server at need for dedicated server,like

home networks ,small business networks, or retail shops. The microsoft term for peer to peer networks is "workshop".

Normal workstation operating system are window 95/98 window ME, NT workstation , window 2000 professional , window XP , vista, window 7,window 8.....etc..

CLIENT  SERVER  NETWORK

PEER TO PEER  networks are good for small business organization. For example :a small factory,service center,a small clinic.. etc. 

The main disadvantage of peer to peer network are list above

* Everything is kept distributed  in different computer.

* User generated  files are stored  in individual computers.Data backup is extremely difficult .

*Each computers has its own user database.

WHAT IS SERVER?

I f computer  has a resource which is served to another computer,it is a server computer .

WHAT IS CLIENT?

A computer which is seeking any resource from another computers is a client computer.

Here,five type of server

(1) File server  

(2) Print server

(3) Mail server

(4) Application server

(5) Database server

(6)Directory server

Types of networks.( lan,wan,can,man)

W

LAN ,WAN,CAN AND MAN

LAN(LOCAL AREA NETWORK)

Local area network is a computer network, which is limited to a small office , single building , multiple building inside a campus etc.

Typically  local area network is a private network owned and maintained by a single organization.

WAN(WIDE  AREA NETWORK)

A wide area network span over multiple geographic location , which b is composed of multiple  LAN's.

It is nearly impossible for a small to medium organization to pull network cables between their two offices in two different countries located 1000s of kilometers away. Network Service Providers provide the connective solution for wide area networks.

Most important categories of computer  networks are local area network and wide area network . LAN and WAN are the mostly widely used terms of describe about computer network .

However , another categories of computer network are also rarely used to describe about computer network.

Following are the two other categories , which are used to de

scribe about computer networks.

CAN(campus area network)

 

CAN (campus area network) : Is the computer network consisting of multiple local area network , which is connected together in a huge campus. for example, inside a huge university, a huge business park or a hug hospital, spanned over multiple building, spread over 100s of acres of land area

MAN(metropolitan area network)

. 

MAN(metropolitan area network) :  Is larger than campus area networks when considering the covered, but smaller than a wide area network.  Metropolitan area network interconnected a number of local area 

networks using a high bandwidth backbone links inside a city.

What is NETWORKING

welcome to networking

 A Computer network or data network is a telecommunication network which allows nodes to share resource. in computer networks , networked computing device exchange data with each other.

using a data link. The connection between nodes are established using either cable media or wireless media. the best-known computer network is the internet.

Computer network differ in the transmission medium used to carry their singles, communication protocols to organize  network traffic , the network size , topology and organizational intent. 

Computer network support an enormous number of application and service such as access to the word wide web, digital video, digital audio, shared use of application and storage servers , printer and fax machines, use of email and instant messaging application as well as many other .

In most cases, application -specific communication protocols are layered over other more general communication protocols. This formidable collection of information technology requires skilled network management to keep it all running reliably.

  

INTRODUCTION

A network can be defined as a group of computer and other device connected in some ways so as to be able to exchange data.

Each of device on the network can be thought of as a node; each node has a unique address.

Addresses are numeric quantities that are easy for computers to work with,but not for humans to remember.

Example:204.160.241.98

Some network also provide names that humans can more easily remember than numbers.

Example:www.javasoft.com,corresponding to the above  numeric address.

ADDRESSING

INTERNET ADDRESS

 - Consists of 4 bytes separated by periods

  example:136.102.233.49

- The R first bytes correspond to the network address.

- The remaining H byte are used for host machine

NIC REGISTER

Organization in charge of the allocation of the address range corresponding to network.

-Geographical area

-Organization

-Department

-Host