Preparation for E2E Recitation

Read End-to-end Arguments in System Design. This paper presents an argument that system designers can use when deciding where to place certain functionality in their system. The first two sections of the paper give many examples of instances where the end-to-end argument applies; later sections discuss some finer points.

As you read, think about the following:

• Should secure communication via encryption be implemented as an end-to-end process rather than in the communication substrate of a system?

• Would guaranteed in-sequence and non-duplicated delivery of packets by a communication subsystem be a good design for all applications?
• Given what you've seen so far in 6.033, where are some places where the end-to-end argument has been applied?

Question for Recitation

Before you come to this recitation, write up (on paper) a brief answer to the following (really—we don't need more than a couple sentences for each question). If your TA has requested that you email your answer to them, you may do that instead, but it should still be handed in before your recitation begins.

Your answers to these questions should be in your own words, not direct quotations from the paper.

• What is the end-to-end argument (what does it state)?
• How is the end-to-end argument used in practice? Give at least one example.
• Do you agree with the end-to-end argument? Why or why not?

As always, there are multiple correct answers for each of these questions. that it is often (but not always) best to implement facilities needed by a complex system at the highest, application layer, with careful engineering tradeoffs needed to analyze when they should be implemented at a lower layer or at multiple layers.