Networking in general means connecting different nodes together in a 'network' of devices, so that they could communicate with each other. Back in the olden days when computer's were first developed, huge corporations used to have large main-frames as the power house, managing all the processes. The users would only sit in front of a dumb-terminal, which was managed completely by the main-frame.
Although, this design worked great for sometime, but as the PC's started to develop and companies started to feel the urge to connect different portions of their buildings in order to consolidate the network, the concept of LAN emerged. This was important because the server client technology couldn't allow communication at large distance and with great speeds.
Currently the most popular LAN technology used is the 'Ethernet', for networking the devices together. Although, the client-server model is still quite popular, yet the protocols used to accomplish this have changed.
Further more, to expand the network across geographical distances WAN also became popular, where several protocols are being currently used for communication, like ATM, Frame-relay, Leased lines, MPLS etc.
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.
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
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
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.