

Computer Networking : A Topdown Approach 

Authors:  James F. Kurose, Keith W. Ross  Chapter:  Computer Networks And The Internet 
ISBN:  9780132856201  Exercise:  Problems 
Edition:  6  Question:  9 
Consider the discussion in Section 1.3 of packet switching versus circuit switching in which an example is provided with a 1 Mbps link. Users are generating data at a rate of 100 kbps when busy, but are busy generating data only with probability p = 0.1. Suppose that the 1 Mbps link is replaced by a 1 Gbps link.
a. What is N, the maximum number of users that can be supported simultaneously under circuit switching?
b. Now consider packet switching and a user population of M users. Give a formula (in terms of p, M, N) for the probability that more than N users are sending data.
a)
Number of users (N)=
So, the maximum number of users that can be supported simultaneously under circuit switching=1000 users
b)
Consider packet switching and a user population of M users.
Formula (in terms of p, M,N) for the probability that more than N users are sending data=