A server accepts at most 3 TCP connections (i.e., at most 3 connections can be active simultaneously).

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Question:

A server accepts at most 3 TCP connections (i.e., at most 3 connections can be active simultaneously). The duration of a connection is a random variable distributed according to an exponential distribution with rate =1 connection/min. Connection request interarrivals is a random variable distributed according to an exponential distribution with rate (lamda2)=2 connection/min.
Compute the probability that an incoming request is not accepted.
Assume two connections are active, compute the probability that the next request arrives before one of the two connections terminates.
Assume one connection is active. Find the probability that at least 2 new connection requests arrive before that connection terminates.