For BCA-III

Written on February 7th, 2013 , Networking Tags: , ,
Advantages of Computer Networks
1. File Sharing: The major advantage of a computer network is that is allows file sharing and remote file access. A person sitting at one workstation of a network can easily see the files present on the other workstation, provided he is authorized to do so. It saves the time which is wasted in copying a file from one system to another, by using a storage device. In addition to that, many people can access or update the information stored in a database, making it up-to-date and accurate.
2. Resource Sharing: Resource sharing is also an important benefit of a computer network. For example, if there are four people in a family, each having their own computer, they will require four modems (for the Internet connection) and four printers, if they want to use the resources at the same time. A computer network, on the other hand, provides a cheaper alternative by the provision of resource sharing. In this way, all the four computers can be interconnected, using a network, and just one modem and printer can efficiently provide the services to all four members. The facility of shared folders can also be availed by family members.
3. Increased Storage Capacity: As there is more than one computer on a network which can easily share files, the issue of storage capacity gets resolved to a great extent. A standalone computer might fall short of storage memory, but when many computers are on a network, memory of different computers can be used in such case. One can also design a storage server on the network in order to have a huge storage capacity.
4. Increased Cost Efficiency:There are many software available in the market which are costly and take time for installation. Computer networks resolve this issue as the software can be stored or installed on a system or a server and can be used by the different workstations.

5. Communication
Communication is one of the biggest advantages provided by the computer networks. Different computer networking technology has improved the way of communications people from the same or different organization can communicate in the matter of minutes for collaborating the work activities. In offices and organizations computer networks are serving as the backbone of the daily communication from top to bottom level of organization. Different types of softwares can be installed which are useful for transmitting messages and emails at fast speed.

6. Instant and multiple accesses
Computer networks are multiply processed .many of users can access the same information at the same time. Immediate commands such as printing commands can be made with the help of computer networks.

7. Video conferencing
Before the arrival of the computer networks there was no concept for the video conferencing. LAN and WN have made it possible for the organizations and business sectors to call the live video conferencing for important discussions and meetings

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8. Internet Service
Computer networks provide internet service over the entire network. Every single computer attached to the network can experience the high speed internet. Fast processing and work load distribution

9. Broad casting
With the help of computer networks news and important messages can be broadcasted just in the matter of seconds who saves a lot of time and effort of the work.
People, can exchange messages immediately over the network any time or we can say 24 hour.

10. Photographs and large files
Computer network can also be used for sending large data file such as high resolution photographs over the computer network to more then when users at a time.

11. Remote access and login

Employees of different or same organization connected by the networks can access the networks by simply entering the network remote IP or web remote IP. In this the communication gap which was present before the computer networks no more exist.

12. Flexible
Computer networks are quite flexible all of its topologies and networking strategies supports addition for extra components and terminals to the network. They are equally fit for large as well as small organizations.

13. Reliable
Computer networks are reliable when safety of the data is concerned. If one of the attached system collapse same data can be gathered form another system attached to the same network.

14. Data transmission
Data is transferred at the fast speed even in the scenarios when one or two terminals machine fails to work properly. Data transmission in seldom affected in the computer networks.  Almost complete communication can be achieved in critical scenarios too.

15. Provides broader view
For a common man computer networks are an n idea to share their individual views to the other world.

Disadvantages of Computer Networks
1. Security Issues: One of the major drawbacks of computer networks is the security issues involved. If a computer is a standalone, physical access becomes necessary for any kind of data theft. However, if a computer is on a network, a computer hacker can get unauthorized access by using different tools. In case of big organizations, various network security software are used to prevent the theft of any confidential and classified data.
2. Rapid Spread of Computer Viruses: If any computer system in a network gets affected by computer virus, there is a possible threat of other systems getting affected too. Viruses get spread on a network easily because of the inter connectivity of workstations. Such spread can be dangerous if the computers have important database which can get corrupted by the virus.
3. Expensive Set Up: The initial set up cost of a computer network can be high depending on the number of computers to be connected. Costly devices like routers, switches, hubs, etc., can add up to the bills of a person trying to install a computer network. He will also have to buy NICs (Network Interface Cards) for each of the workstations, in case they are not inbuilt.
4. Dependency on the Main File Server: In case the main File Server of a computer network breaks down, the system becomes useless. In case of big networks, the File Server should be a powerful computer, which often makes it expensive.

Written on November 23rd, 2012 , Networking Tags: ,
Sr No. IPv4 IPv6
1 IPv4 (Internet Protocol Version 4) is the fourth revision of the Internet Protocol IPv6 is the successor to Internet Protocol Version 4 (IPv4).
2  32-bit numeric address written in decimal as four numbers separated by periods. Each number can be zero to 255.Example, 192.168.1.10 IPv6 addresses are 128-bit IP address written in hexadecimal and separated by colons.Example  3ffe:1900:4545:3:200:f8ff:fe21:67cf
3 Manual configuration (Static) of IP addresses or DHCP (Dynamic configuration) is required to configure IP addresses. Auto-configuration of addresses is available.
4 Deployed in 1981 Deployed in 1999
5 The number of header field 12 The number of header field 8
6 Checksum field, used to measure error in the header, required Checksum field eliminated from header as error in the IP header are not very crucial
7 Internet Protocol Security (IPSec) with respect to network security is optional Internet Protocol Security (IPSec) with respect to network security is mandatory
8 The fragmentation is done both by sending host and routers The fragmentation is done both by sending host. Pv6 simplified the router’s task compared to IPv4.
9 Clients have to approach Dynamic Host Configuration Server (DHCS) whenever they connect to a network. Clients do not have to approach any such server as they are given permanent addresses.
10 IPv6 is less compatible to mobile networks IPv6 is more compatible to mobile networks than IPv4.
11 IPv6 allows lesser payloads IPv6 allows for bigger payloads than what is allowed in IPv4
12 IPv4 is in use by 99% networks. Pv6 is used by less than 1% of the networks,
Written on November 23rd, 2012 , Networking Tags: , ,

 

Important Point :

  • Hub (Old technology)
  • Switch (New Technology)
  • MAC Address (Permanent Address of computer)
  • How to read Mac Address.

Hubs and switches are all devices that let you connect one or more computers to other computers, networked devices, or even other networks. Each has two or more connectors called ports into which you plug in the cables to make the connection. Varying degrees of magic happen inside the device and therein lies the difference. I often see the terms misused, so let’s clarify what each one really means.

Hubs

hub is typically the least expensive, least intelligent, and least complicated of the three. Its job is very simple – anything that comes in one port is sent out to the others.

That’s it.

If a message comes in for computer “A”, that message is sent out all the other ports, regardless of which one computer “A” is on:

Message coming into a hub

And when computer “A” responds, its response also goes out to every other port on the hub:

Response being sent through a hub

Every computer connected to the hub “sees” everything that every other computer on the hub sees. The computers themselves decide if they are the targeted recipient of the message and when a message should be paid attention to or not.

The hub itself is blissfully ignorant of the data being transmitted. For years, simple hubs have been quick and easy ways to connect computers in small networks.

Switches

switch does essentially what a hub does, but more efficiently. By paying attention to the traffic that comes across it, it can “learn” where particular addresses are.

Initially, a switch knows nothing and simply sends on incoming messages to all ports:

The initial contact through a switch

Even accepting that first message, however, the switch has learned something – it knows on which connection the sender of the message is located. Thus, when machine “A” responds to the message, the switches only need to send that message out to the one connection:

Response being processed through a switch

In addition to sending the response through to the originator, the switch has now learned something else – it now knows on which connection machine “A” is located.

That means that subsequent messages destined for machine “A” need only be sent to that one port:

Switch sending an incoming message to the machine who's location it is aware of.

Switches learn the location of the devices that they are connected to almost instantaneously. The net result is that most network traffic only goes where it needs to rather than to every port. On busy networks, this can make the network significantly faster.

Written on November 23rd, 2012 , Networking Tags: ,

Welcome , this is the blogging site for the Laureate employees and students.

 What is a “blog”?

“Blog” is an abbreviated version of “weblog,” which is a term used to describe web sites that maintain an ongoing chronicle of information. A blog features diary-type commentary and links to articles on other Web sites, usually presented as a list of entries in reverse chronological order. Blogs range from the personal to the political, and can focus on one narrow subject or a whole range of subjects.

Knowledge Sharing

Many blogs focus on a particular topic, such as web design, home staging, sports, or mobile technology. Some are more eclectic, presenting links to all types of other sites. And others are more like personal journals, presenting the author’s daily life and thoughts.

‘A weblog is a hierarchy of text, images, media objects and data, arranged chronologically, that can be viewed in an HTML browser.’

‘A frequent, chronological publication of personal thoughts and Web links.’

‘A blog is basically a journal that is available on the web. The activity of updating a blog is “blogging” and someone who keeps a blog is a “blogger.”‘

Blogging

‘A blog is a website in which items are posted on a regular basis and displayed in reverse chronological order. The term blog is a shortened form of weblog or web log. Authoring a blog, maintaining a blog or adding an article to an existing blog is called “blogging”. Individual articles on a blog are called “blog posts,” “posts” or “entries”. A person who posts these entries is called a “blogger”. A blog comprises text, hypertext, images, and links (to other web pages and to video, audio and other files).’

For Laureate Institute

‘Blogging Provide the open diary to all the teachers , Students and their Parents which increase the effectiveness and credibility of education.’

 

Blogs are shared through out the World

Importance of  blogging

1 Knowledge sharing at Any Time and Any Where
2. Time Saving
3. Free to discuss at Any Time
4. Make more Tech Savvy
5. Open To All
6. Discuss World Wide
7. Helps in Learning
8. Increase social Network
9. Make yourself  Up to Date
10. Cope with e-world

Written on September 4th, 2011 , Laureate, Teacher

Laureate is proudly powered by the64u Solution, a project for the students and teachers of Laureate Institute to share their knowledge by Blogging at any Time & any Where.

Laureate

Share your Knowledge any Time and any Where