Hello I need help with these 3 questions:

1. Mark the collision and broadcast domain in the network shown in Fig. 1.

2. Consider the network shown below with nineteen routers. For a single packet sent from source (S) to destination (D), what is the total delay if each link is of length 100 KM, the packet size is 1000 bits, the link bandwidth is 1 Mbps and signal travels at the rate of 2*108 meters/second on all the three links. Ignore processing delays.

3. Router R1 is connected to another router R2 with link of L1 with a transmission rate of 67 packets/second. The link buffer at router R1 contains on an average 15 packets. There is one packet being currently transmitted. Average packet queuing delay is 15 milliseconds. Assuming no packet loss, what is the average packet arrival rate at R1?

Please give a proper response and answer all 3 questions. Thank you.

ivetwork ior prodiem 14