1. Consider a router that receives packets from three different sources of traffic, each ranked in order of priorities (source 1 has highest priority -class 1, source 2 has class 2 priority and finally source 3 has lowest priority - class 3). Source 1 generates traffic with rate lambda1 = 10packets/sec; source 2 has arrival rate lambda2 = 20packets/sec and source 3 has lambda3 = 15packets/sec. All traffic generated is Poisson distributed. The router forward the packets to another router over a line with a constant transmission rate mu = 25pkts/sec, using a preemptive resume policy for the queuing.
a) What type of queue is implemented at the router?
b) What is the delay for each class of traffic? Justify by calculations.