Authors: Henry Post Darian Gurrola Davvid Caballero

History of TCP/IP Began as a project under the DoD in the 1960s. Later adopted by various universities to maintain networks, and initially named ARPANET. Functioned as a simple way to transfer packets between computers. Evolved from ARPANET to work as a regulator for communication between computers and networks. Led to the internet we know today, and still plays a very important part in communications.

What is an IP address? Each and every computer that you use that connects to the internet or a network uses a specific range of numbers separated by periods that is called an IP address, or an Internet Protocol address. For a computer to communicate with its Internet Service Provider (i.e. Comcast, AT&T, etc) and other servers/clients, it needs to be assigned an IP address to be identified so servers can serve it information while knowing where to serve the information.

IP Functions IP or Internet Protocol controls routing of information to different computers, different devices and different servers on the same network. Using the IP address the router directs information to the computer requesting it. This allows two computers to figure out where the other one is so that they can start communication.

TCP Functions All data sent over the internet using TCP/IP is broken down into 'packets' Because the quality of the transmission lines between computers are unknown the client computer sends one packet first. The server computer then sends an acknowledgement that it has received the packet, the client computer now sends more packets If there is a problem with one or more of the packets the process starts over

The four layers of TCP There are basically four layers of connectivity that a host can have to a server, and here I will explain them. 1 st layer: The link layer Is the scope of the Local Area Connection that the host is attached to 2 nd layer: The internet layer Holds responsibility of “routing” packets to other places Uses hierarchical identification system (IP addresses) to identify locations/sources 3 rd layer: The transport layer Ensures that: Data is sent in order Data has minimal error Duplicate data is discarded Discarded data is re-sent 4 th layer: The application layer This layer covers how high-level processes (i.e. Skype, a videoconferencing software) communicate from client-client and client-server standpoints.

Problems with TCP/IP Generally has very low security standards. Lacks encryption or authentication requirements, causing vulnerability. Absence of encryption allows packets to be intercepted between computers and manipulated. Faulty security because of it was not meant to be used on such a large scale. As the internet grows, TCP/IP becomes increasingly easy to target.