9 Figure 1: A network graph with associated link costs 8) Two neighboring nodes (A and B) use a sliding window protocol with a 3-bit sequence number. As the ARQ mechanisms, go-back-N is used with a window size of 7 frames. Assuming A is transmitting and B is receiving, show the window positions for 'A' for the following succession of events: [3+3+3] a. Before A sends any frames b. After A sends frames 0,1,2 and receives ACK from B for 0,1 and 2 C. After A sends frames 3, 4, 5 and 6 and B sends RR4 and it is received by A 9) For the given network diagram, use Dijkstra's algorithm to find the shortest path from node 'A'(source) to node 'D' along with the cost. Show sequentially the nodes which become the working node and how the cost to reach a particular node along with the previous hop neighbor is updated in every step. [10]