Read + Write + Report
Home | Start a blog | About Orble | FAQ | Blogs | Writers | Paid | My Orble | Login

What Is A VPN?

December 24th 2011 20:22
Encryption of packets requires extensive resources, corporate environments use, dedicate hardware devices to provide power to handle IPSec encryption. Juniper's SSG is one of the widely used security devices in the market.


People who have used a VPN service to access blocked websites in their offices or school campuses, might just know that a VPN is simply a way to anonymously surf the internet. But a VPN has much more to it, infact it has come up as the most secure way to connect with each other on the Internet, no matter where your location is.


VPN stands for Virtual Private Network. It is simply a virtual connection over the Internet between two sites. As we all know that the Internet is a network of networks where millions of nodes are interconnected all talking to each other using different type of circuits. In order to transfer data to another remote workstation through the Internet, you can imagine how many routes the packets have to take before reaching the destination.

Therefore anybody in the intermediate network can sniff the packet and extract all the critical data out of it. Therefore there should be some way of protecting the data. We use the 'https' service for accessing confidential data on the internet, but how about encrypting the data at much lower levels of the OSI layer to allow communication between many nodes just like we do in a local area network.

This is what a VPN does! It basically encrypts the IP packet using the IPSec suite of protocols, which provides a mechanism of authentication and encryption of IP packets on the Network layer of the OSI layer model along with other encryption mechanism on top of it. These mechanism are the Secure Socket Layer (SSL) and Transport Layer Security (TLS) at the Presentation layer; the same mechanism is used for encryption of the Https service.


This full proof security of VPN allows you to connect with different nodes on the Interent just like you do locally, it is infact considered a type of WAN where different offices are now connecting there branches over cheap and high speed DSL connections using VPN. However a dedicated circuit is till established over several of the WAN technologies as they provide what is called as a Service Level Agreement (SLA) to deliver a guaranteed bandwidth and uptime, which is not available with a DSL connection.
10
Vote
   


Types Of RFID Tags

October 25th 2011 05:13
Passive RFID Tag


Recently I had chance to work in a RFID project, which allowed me to post some basic stuff about RFID here in my blog too. RFID is a promising technology, which has its origin dating back to 1945.

Radio frequency spectrum is quite an old phenomenon which was already applied in conventional radio years back. But no one knew what wonders we can achieve with this spectrum.

RFID stands for Radio Frequency Identification, it consists of two main components, namely an Interrogator and the Transponder. The Interrogator is actually a scanning device just like barcode scanner, which can scan the different RF tags from a particular distance.

The Interrogator consists of an RF transceiver which, sends and receives data on free ISM band. The Interrogator is typically connected to a computer database where real time updates are made to a database.

The RFID tags called the transponder are of two types:

1. Active Tags

Active tags are really promising for the reason that they can be scanned from a large distance which can be more than 100 meters. That is why they have been popular in applications like toll charging on free ways and highways. But its draw back is that it requires a battery to remain active, however it allows us to send and receive data without communication being initiated from the Interrogator.

2. Passive Tag

Passive tags are the more widely used ones mainly because they are extremely compact and that they are comparatively cheaper than active tags. This allows them to be suitable in inventory management systems, where they can be effectively placed on hundreds of items, for Asset tracking. Passive Tags work when an Interrogator initiates communication my sending an RF signal which hits the tag and makes it active to send back the data it has stored . It has a typical range of upto 5 meters.
18
Vote
   


Types Of Routing Protocols

August 26th 2011 13:32
Cisco Branch Router (Courtesy Cisco)


In the last post we focused on IPv6, which is the next generation of Internet Protocol. In this post lets head back to some of the more basic concepts of IPv4 which is routing.

Router in general is a device that transfers packets from one network to another thus allowing the creation of a large internetwork that can be as large as the Internet itself. Routing is not just transfer of IP packets but instead all the networking protocols that exist like Appletalk, IPX etc are also forwarded using routers.

Without routers there would be no Internet! A router accomplishes this task of transferring packets through complex algorithms that run on its hardware. These algorithms in the networking world are called the Routing Protocols, that run on the Layer 3 of the OSI Later.

Cisco claims to be the first to have made a Router and has its own operating system called the Cisco IOS. This IOS is responsible for executing the Routing function on the platform.

Routing Protocols can be divided into two main categories:

1. Interior Gateway Protocol

Interior Gateway Protocols (IGP) are further classified into:

a. Distance Vector (RIP, IGRP)
b. Link State (OSPF, IS-IS)
c. Hybrid (EIGRP)

2. Exterior Gateway Protocol

The Exrerior Gateway Protocols (EGP) are used between Autonomous Systems and have only one Routing Protocol that is currently being used on the Internet which is the Border Gateway Protocol (BGP).
9
Vote
   


Who Needs IPv6?

June 28th 2011 19:45
Internet


IPv6 is the next generation of internet. It was developed by IETF in 1998 primarily to replace the older version IPv4. IPv4 is the current network layer protocol on which the Internet depends. But IPv4 has a serious issue, which is, that it has only 4.3 billion theoretical addresses, which have to be used by the entire devices in the world


[ Click here to read more ]
27
Vote
   


Different Types Of Cranes

April 30th 2011 17:14
Tower Crane


Every since the ancient times man has been figuring out ways to move heavy objects through long distances. They used beast of burden initially to move and lift heavy stuff


[ Click here to read more ]
27
Vote
   


Monitors And Monitor Types

March 3rd 2011 09:31
LCD Monitor


Monitor is an important output device without which a computing machine is incomplete. Back in the olden days computer operators used to get output through punched cards, that used to show us result of a calculation


[ Click here to read more ]
27
Vote
   


Top Inventions Of 21st Century

January 4th 2011 19:50


Technology is some thing that now has become an integral part of our life. Some decades back people wouldn't have even imagined that we would have a device such as a smart phone in our hands


[ Click here to read more ]
33
Vote
   


Top Inventions Of The 20th Century

November 6th 2010 12:04

The 20th century is the most revolutionary era in modern day technology. Although the Industrial Revolutions started much earlier, but in this century the face of the earth really changed, with in a span of decades.

[ Click here to read more ]
63
Vote
   




The Kiva systems marks a revolution in warehouse storage and delivery processes. Until now the traditional technology used for warehouse management was using completely manual approach


[ Click here to read more ]
89
Vote
   


Biofuel And Its Types

July 14th 2010 09:48


Automotive technology is making new breakthroughs every passing time. Every now and then when there is a motor show we see cars showing off entirely new engineered engines and some of the best artistic designs taking us ahead in the future


[ Click here to read more ]
192
Vote
   


More Posts
1 Posts
1 Posts
1 Posts
72 Posts dating from July 2008
Email Subscription
Receive e-mail notifications of new posts on this blog:

hassam's Blogs

6883 Vote(s)
23 Comment(s)
98 Post(s)
3223 Vote(s)
4 Comment(s)
39 Post(s)
3407 Vote(s)
22 Comment(s)
43 Post(s)
Moderated by hassam
Copyright © 2012 On Topic Media PTY LTD. All Rights Reserved. Design by Vimu.com.
On Topic Media ZPages: Sydney |  Melbourne |  Brisbane |  London |  Birmingham |  Leeds     [ Advertise ] [ Contact Us ] [ Privacy Policy ]