Computer Networks

Tutorial #20

1. Why are applets needed to achieve interactivity on Web pages? Can't you achieve the same thing using forms and CGIs on the server?

2. Why does Java compile to bytecode instead of to real binaries for a (for example) PC - ie, a .exe file? At least two answers required here!

3. Why would an organisation buy Network Computers instead of (eg) Windows PCs for desktop machines?

4. Give an example of why we referred to in the lecture as batch mode multimedia on the Internet. What does this expression mean?

5. Within a LAN, how do you think a multicast packet differs from a broadcast packet?

6. Why do you think the Silicon Graphics "dogfight" game uses multicasting to share information between players instead of simple broadcasts?

7. What is the principal advantage of the MBone approach compared to (eg) RealAudio as a means of delivering "streaming" audio and video on the Internet? Discuss some reasons why MBone technology isn't commonly used in the Internet.

Practical exercises:

• Visit http://java.sun.com/

• Visit the Network Computer, Inc. page.

• Even though the Mbone tunnel between RMIT and Bendigo isn't yet relayed to the student subnets, you can still use the MBone software tools. Try the session directory tool, sdr. You can also use vic for video and vat for audio. Experiment with these on the Indys sometime when the lab isn't crowded. Take care when creating new sessions!