INT21CN Computer Networks

Tutorial #24

1. What is a canonical form? Why is it considered a Good Thing™ in computer networking, and what are the alternatives?

2. Text-based protocols such as HTTP introduce the need for parsing. What is parsing, and why is it needed in these protocols?

3. Markup tags in XML are entirely structural (or semantic), compared to HTML where these types are intermingled with presentational tags. What is the difference between these two types, and why is the XML approach considered better? Discuss.

4. What is considered to be the particular advantage of Remote Procedure Call and/or Distributed Object programming, compared to the socket-based networked applications which we have considered earlier in the unit?

5. Consider the positive integer 1003421_dec, used as an example in the lecture. This number is be sent across a network using a variety of encodings: as the value of a "Content-length: " header in HTTP, as an integer in an SNMP response, and as an XDR-encoded integer. Give the actual values in hexadecimal of (all of) the bytes which would be sent in each of these encoding schemes. For your information: the ASCII "zero" character ("0") has byte value 30_hex.

6. What do understand by the term "Web Services"?