Web Science/Part1: Foundations of the web/Internet Protocol/Motivation for IP

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Motivation for IP


Learning goals

  1. get introduced to the concept of an IP-network
  2. understand that networks can be interconnected
  3. learn about the importance for decentralization as a design principle
  4. realize that Local area networks can be fragmented via IP networks




There are some limitations over the Ethernet

1) Transport distance should be shorter than 500 meters. So obviously you just can’t create one big Ethernet network.
Let’s imagine that we have some geographically distributed networks. And these networks should be interconnected to each other. So you have really small networks that can just add locally in a certain region and you want to interconnect those networks.
2) Collisions.
With the non deterministic protocol every time someone wants to sent some data he has to occupy the entire network and if there are too many clients there collisions will arise all the time with the result that no one will be able to pass any message. Another requirement to create Internet was to have it decentralized. When Americans decided to create this communication system they did it mainly for the military reasons. They already knew that if you have 1 single spot where all communications go through it is very easy to attack this spot and then your entire communication doesn’t work.
In decentralized system we can see that if one network fails still all the networks will be at least with some connection to each other. If we will make it like star topology then if one central network fails you are in trouble because your system has no way of communicating anymore.
Summing up
Internet was designed:
- To connect local area networks
- To be decentralized not to have a single point of failure
- To fragment LAN. So if there too many hosts in LAN you can separate networks.
And in order to achieve all these things an IP was designed.
--Jane Kruch (discusscontribs) 09:31, 31 October 2013 (UTC)



1 What does the robustness principle say?

The internet should be built in a decentralized way to have no single point of failure.
Be conservative in what you do, be liberal in what you accept from others.
Be conservative in what you send, be liberal in what you accept
The Internet protocol should be so lightweight that its byte code can easily be used on any router.
There must exist at least 3 disjunctive different routes between each pair of hosts on the internet.

2 Which core problems have been addressed while designing the Internet Protocol

Creating a reliable protocol to transfer data between any two computers as long as they are connected via some route
Enable hosts on two different networks to communicate with each other.
Creating a tool for decentralized fail-proof communication between hosts.
Fight the short comings of Ethernet by creating a way for hosts to communicate over links which are longer than 1 kilometer.

3 What are the advantages of segmenting networks?

Package switching protocols on a shared medium will result in too many collisions if the network is not segmented.
Every network can use its own link layer protocol.
Securing Ethernet packages will become possible through segmentation.
Computer viruses will not be able to spread over network boundaries.