Dawn Of The Net

Warrior Of The Net (description)


-This is a good video that show how the internet work. This video show what happen inside the network when you type an URL or web address to surf the internet. how the URLs that you types in address bar is sent to the server until the information you requested displayed in your computer monitor.

     When user clicks the links or enters URL in the web browser, the information is going to the lower level of the OSI model and break into parts of a certain size in bytes called packets. In the lower level, IP (internet protocol), is responsible for labeling each packets with the information such as sender address, receiver address and the type of packet it is. The packet also gets an address for the Proxy Server. Each packet is limited in its size and the size of each packet also different with each other according to the transmission media in the network and the type of service. The packets then send through the wire of Local Area Network or LAN. All the local network such as computers, routers, printers and other is connected to this network and using the same wire for information exchange within the physical walls of the building. The LAN is packed with all types of information such as IP packets, Novell packets, Apple Talk packets. Here, the role of the local router is to reads the address of the packets and if necessary route the packet onto another network route. Router has the map of the Internet in its memory which is the complete map of its network neighborhood. The packet may pass through several routers on the way to its destination. When, the packets leave the router, the packets then head to the router switch before enter the internet network.

When the packets arrive at their destination, the network interface will pick up the packets to be sent to the proxy. The proxy is responsible to lessen the load of the internet connection and also for the security reason. The proxy will filter which packet is allowed to the internet. The proxy will opens the packet and looks for the WEB address and URL. Based on the information or the configuration of that proxy, the packets that not meet the criteria will be destroyed and for the packets that approved by proxy will be continuing their journey.

After that the packets will go through the fire wall. The fire wall serves two purposes which is prevents some other nasty thing from internet from coming into the intranet and also can prevent sensitive data from being sent out to the internet. In short, fire wall is responsible in controlling what is going to internet and what is allowed to enter the intranet. Here, packet sometimes lost and when it happens, the browser resends the replacement packet.

And now, the packets enter the world of the Internet. Here, the routers and switches establish links between networks. The path that the packets take can be different which is maybe via satellite, telephone lines, wireless or cable under ocean. The packet will be routed based on the routing protocol that being used.

Near the end of the packet destination, there is another wall that controls the packet that come in and come out. The fire wall is designed to let in only those packets that meet its criteria. From this example, the fire wall is operating on port 80(HTTP) and port 25(SMTP) only. The packets that attempt to enter other than port 80 and port 25 are not allowed to pass through.

The packets that meet the criteria will be taken to the web server. Web server will open and unpack the packets and look up for information that contained which is the request from user. The packets then recycled and filled with the requested information that will be sent to the user who request the information based on the sender address. Here, the process is reversed until the information arrives and displayed onto sender interface.

here is the text file of what have been said in the video: Dawn of the Net