15. Network communication protocols

Warning

This chapter has not been developed yet. It covers one of six topics that students must select two from for the Achievement Standard 3.44; the other 5 topics have chapters available, so there is still a wide range of choice available. This chapter will be developed during 2013, but it is not guaranteed to be ready in time for teaching 3.44 during 2013.

The brainstorming material is in the Brainstorming section at the end of the chapter

Note

For teachers

This chapter supports the “Network communication protocols” option of the NZ achievement standard 3.44.

Currently all material in this chapter is relevant to the standard, although students can choose one or two examples to focus on to meet the requirements of the standard.

15.1. What’s the big picture?

Network communication protocols focus on the techniques applied in computer networks to ensure reliable communication of data between two parts of a network in the face of different kinds of threats and failures. The project would typically be done by giving examples of the sequence of events that occur in these situations, discussing how the protocols and their coding schemes overcome the problems, and evaluating how successful they are at addressing them. This topic is distinct from the coverage of networking in the infrastructure standards because it focuses on the issues that the protocols address (i.e. the design of the protocol), rather than how to configure a system that uses a given protocol

The following lists are concepts, algorithms, techniques, applications and problems that students at level 3 are likely to be able to work with; it isn’t a list of all the key ideas in the area.

15.1.1. Key concepts

Key concepts that are likely to be encountered are: addressing, reliability, security, failure, packet loss, human-readable addresses, quality of service, network performance, cyber attacks, routing Algorithms: (techniques are more relevant to this area than algorithms) Techniques: packet switching, handshaking, acknowledgement, authentication, checksums, wireless and wired security Applications: many real protocols (e.g. TCP/IP) could rapidly become overwhelming at this level. Protocols that students could investigate that are less complex are DNS, UDP, HTTP (get and post), the addressing part of IP, SMTP and CDMA, and Internet security protocols such as SSL, IPSec and PGP.

15.2. Getting started

[some introductory activities/ideas to open up the topic]

15.3. Subtopic 1

[an area that is worth knowing about, including activities/exercises to explore it, and guidance for teachers (possibly to be separated) on how to help students use this topic for A/M/E

15.4. Subtopic 2

[an area that is worth knowing about, including activities/exercises to explore it, and guidance for teachers (possibly to be separated) on how to help students use this topic for A/M/E

15.5. Subtopic 3

[an area that is worth knowing about, including activities/exercises to explore it, and guidance for teachers (possibly to be separated) on how to help students use this topic for A/M/E

15.6. Subtopic n

[an area that is worth knowing about, including activities/exercises to explore it, and guidance for teachers (possibly to be separated) on how to help students use this topic for A/M/E

15.7. The whole story!

[explain where the material above has oversimplified things, and if there are any well-known concepts or techniques that have been deliberately left out because they are too complex for this age group. This may include things that require advanced maths, advanced programming, or things where students have seen the problem but not a thorough solution]

15.8. Further reading

Real snail mail (a snail as part of the network): http://www.cs4fn.org/internet/realsnailmail.php - see also pigeon RFC?

15.8.1. Possible Activities

  • Use tools like traceroute to evaluate the time taken and number of hops required for packets to be transmitted through the internet.
  • Using packet analyser software (e.g. wireshark), trace the sequence of exchanges that occur for a protocol such as DNS, UDP or HTTP using an example on your own system.
  • Participate in and document the “tablets of stone” activity (http://csi.dcs.gla.ac.uk/workshop-view.php?workshopID=4)
  • Explain how HTTP provides the foundation of the World Wide Web, how IP solves the problem of individually addressing the thousands of computers that comprise the internet, and/or how DNS makes the internet friendly for human users.
  • Use tools to how encryption algorithms and security protocols can provide confidentiality, integrity and availability of information exchanged between parties.