This lecture describes many of the design decisions that have to be made to generate an architecture for inter-networking. The current networking architecture may seem obvious from hindsight, but is actually built on decades of careful thought, experimentation and research. We will describe the four main sources of delay in the network and determine how they are affected by architectural choices. Then, we will discuss the very idea of building a layered architecture, especially the advantages and disadvantages of having layers. Finally, we will describe the OSI model and take a quick look at what the layers all do.
By the end of this lesson, the student will be able to:
read, comment upon and review research papers with a strong process to store and search the knowledge gained from the paper.
calculate delay in a packet-switched network as a sum of nodal processing delay, queueing delay, transmission delay and propagation delay.
describe the algorithm used by traceroute to measure delay in real networks. Additionally, be able to use traceroute and interpret its output.
argue the benefits of a layered architecture (as compared to monolithic).
describe the internet's layered architecture according to the OSI model, including the mission of each layer, the scope of the layer, the type of data transferred by the layer and summary of the execution steps accomplished.