# Question 5 Itotal Marks 25 13 Marks Consider Leaky Bucket Capacity B Tokens Refill Rate R Q30539208

QUESTION 5 ITOTAL MARKS: 25] [13 Marks] Consider a leaky bucket with a capacity of b tokens and a refill rate of r tokens per Q 5(a) second i) Describe how a leaky bucket policy works. (4 marks) i) What three factors can be controlled by use of one or more leaky buckets? (3 marks) ii) Under a leaky bucket policy, prove that the long-term average rate for the flow is given by r. (6 marks) Q 5(b) Suppose we wish to implement a DiffServ Architecture as follows [12 Marks] There are three classes of traffic o The first class should be allocated 60% of available bandwidth o The second class should be allocated 30% of the available bandwidth o The third class should receive the rest Additionally, streams for the classes transmit at different rates The first class transmits at 1Mbps . The second class transmits at 50kbps . The third class transmits at 10kbps i) Suggest a Weighted Fair Queuing policy to enforce the allocation requirement for the system. (4 marks) bandwidth li) Suppose the overall system bandwidth is 4 Mbps 1) What is the maximum number of streams of each traffic class that may be supported 2) Why might that maximum number not be achievable in practice? (5 marks) ii) Suppose that the third class requires absolutely no bandwidth guarantees while the first and second are as before. Suggest your own policy to share the bandwidth according to this scenario. (3 marks) Show transcribed image text QUESTION 5 ITOTAL MARKS: 25] [13 Marks] Consider a leaky bucket with a capacity of b tokens and a refill rate of r tokens per Q 5(a) second i) Describe how a leaky bucket policy works. (4 marks) i) What three factors can be controlled by use of one or more leaky buckets? (3 marks) ii) Under a leaky bucket policy, prove that the long-term average rate for the flow is given by r. (6 marks) Q 5(b) Suppose we wish to implement a DiffServ Architecture as follows [12 Marks] There are three classes of traffic o The first class should be allocated 60% of available bandwidth o The second class should be allocated 30% of the available bandwidth o The third class should receive the rest Additionally, streams for the classes transmit at different rates The first class transmits at 1Mbps . The second class transmits at 50kbps . The third class transmits at 10kbps i) Suggest a Weighted Fair Queuing policy to enforce the allocation requirement for the system. (4 marks) bandwidth li) Suppose the overall system bandwidth is 4 Mbps 1) What is the maximum number of streams of each traffic class that may be supported 2) Why might that maximum number not be achievable in practice? (5 marks) ii) Suppose that the third class requires absolutely no bandwidth guarantees while the first and second are as before. Suggest your own policy to share the bandwidth according to this scenario. (3 marks)

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