Q8. Suppose users share a 20 Mbps link. Also suppose each user requires 2 Mbps when transmitting, but each user transmits only 20 percent of the time

- When circuit switching is used, how many users can be supported?

- If there are 30 users: Can this many users be supported under circuit-switching? Yes or No. Can they be supported under packet-switching?

- For the remainder of this problem, suppose packet switching is used. Find the probability p that a given user is transmitting

- Suppose there are 30 users. Find the probability that at any given time, exactly 10 users (i.e., P(X=x)) are transmitting simultaneously. Use a binomial calculator (such as these BinCal I or BinCal II)

- Find the probability that there are 10 or more users transmitting simultaneously. (P(X>=x))

- Find the probability that there are 20 or more users transmitting simultaneously. (P(X>=x))

Q9. What is the difference between a virus and a worm?

Q10. Describe what is meant by access networks.

- What are the different types of links (physical media) used in access network? Name some technologies