Computer Networking

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ECE 436 – Computer Communication Networks II Take-Home Quiz 5

Q1. Analog audio signals are sampled first, and then quantized. What is the purpose of quantization? Is it possible to design an error-free quantization mechanism? Q2. Why are video files are compressed? What is the main approach for compressing videos? Q3. Consider the simple model for HTTP streaming shown in the following figure.

Suppose the buffer size is infinite, but the server sends bits at variable rate x(t). Specifically, suppose x(t)

has the following saw-tooth shape. The rate is initially zero at time t = 0 and linearly climbs to H at time t

= T. It then repeats this pattern again and again, as shown in the figure below.

What should be 𝐻 in terms of 𝑟 to eliminate freezing scenes on the average?

Q4. What are the advantages and disadvantages of UDP and TCP from streaming multimedia

perspective?

Q5. A single, large “mega-server” does not work for content delivery. Why? What is the solution?

Explain.

Q6. What are the approaches for selecting a good content delivery network (CDN) node/server?