Question

A packet switch has 5 users, each offering packets at a rate of 10 pps. The average length of the packets is 1024 bits. The packets switch needs to transmit this data over a 56-kbs WAN circuit. Given Queue depth = Utilization / (1-Utilization). Calculate the average number of packets in the queue (also called Queue depth).

Answer 1

Average number of packets in queue(queue depth) = 10.63packets

Step-by-step explanation:

We are given:

Number of users = 5

Rate= 10pps

Average packet length = 1024bits

To find the average number of packets (queue depth), we are given the formula:

`Queue depth = (Utilization)/(1-Utilization)`

But we need to find utilization first, therefore

Utilization = load/ WAN

But load=5*10*1024bits =51200bps

Utilization = 51200/56000 = 0.914

Therefore,

`Queue depth = (0.914)/(1-0.914)`

= 10.63 packets