(b) TCP uses two windows to control the rate at which it can send data into a network. Explain what these two windows are and how they are updated assuming no losses in the network. Give two examples of how a TCP sender would detect the occurence of congestion in a network. [10 marks] (c) A graph G is composed of a set of vertices, V, and a set of edges, E. The number of vertices and edges is denoted V and E respectively. The graph G is said to be clean if the nodes do not know the topology of the graph. A Link State routing requires knowledge about the link states of the network. State the messaging complexity required to gather this information. Justify this expression. [5 marks] (d) Describe the advantages of performing modular exponentiation iteratively in RSA. Compute the value of c=bemodm using an iterative modular exponentiation procedure for b=4,e=4 and m=497. Show each step of this iteration. [10 marks]