This thesis is designed in two parts. One of them is the text document that conveys knowledge from the field of computer networking, and in the same time serves as a documentation for the other part of this thesis, the developed computer network packet transmission simulator. These two integral parts create a complete bachelor thesis. The simulator is based on TCP/IP network model, which is the backbone of the world's biggest network, the Internet. The sheer reach of the Internet, and it's daily use from billions of users were the main motive for choosing this perticular theme, and the creation of this simulator that has, as it's main goal, the purpose of acquainting an average user to the way computer networks function from the perspective of a packet, or a data unit that is sent through the network. The simulator is designed as a software that can be used as an educational tool for teaching a variety of different users (regarding their previous knowledge). The programing language chosen and used for the development of the simulator is C#. It is used besause of it's simplicity while working with graphical elements, and because of it's popularity and it's market presence.