1. Computer Networks Fall, 2007 Prof Peterson

2. CIS 235: Networks Fall, 2007 Western State College Homework #5 We will be talking about other protocols. Everyone will be doing a different protocol (or sub-part of a protocol). You’ll be doing the following: Writing a thumbnail sketch of the protocol Showing actual traffic on that protocol Finding at least 4 interesting facts about it I’ll be putting this up later today. I’ll assign the protocol to everyone. Protocols: DNS, SMTP, IMAP, AIM, NNTP, POP

3. CIS 235: Networks Fall, 2007 Western State College http Messages  What are headers? What sort of information is contained in them?  What is the entity body?  What is the difference between GET and POST?  How can a form send data to the server without POST?

4. CIS 235: Networks Fall, 2007 Western State College http Messages  How does the server tell the browser how big an object is?  What is the content-type? What types are there?  Why does the server tell the browser the last- modified date?  What does the status code indicate?  What is a cookie?  What is caching?  What is conditional GET?

5. CIS 235: Networks Fall, 2007 Western State College Electronic Mail  What is the difference between an agent and a mail server?  What are the big issues that need to be addressed in an email system?  Where does your mailbox live?  How is mail formatted?  How does SMTP figure out who your mail agent is?  What sort of information is encoded in an email header?