- Forward


Electronic Mail and Instant Messaging
An Introduction


Prof. David Bernstein
James Madison University

Computer Science Department
bernstdh@jmu.edu

Print

Getting Started
Back SMYC Forward
  • Electronic mail protocols and instant messaging protocols are both application level protocols
  • There are many variants -- we'll consider some pure examples and then some hybrids
Electronic Mail
Back SMYC Forward

The Classic Approach

email
Electronic Mail Protocols
Back SMYC Forward
  • SMTP RFC 5321:
    • Transfers message from the sender's server to the receiver's server
  • Access Protocols:
    • POP3 RFC 1939 (provides for authentication and download)
    • IMAP RFC 3501 (adds server-side storage)
Instant Messaging
Back SMYC Forward

The Classic Server-Based Approach

im-server
Instant Messaging
Back SMYC Forward

The Classic Peer-to-Peer Approach

im-peer
Thinking About Messaging
Back SMYC Forward
  • An Observation:
    • The differences between electronic mail and instant messaging systems have not been considered systematically
  • What Are The Issues?
    • Synchronous or Asynchronous
    • Full Duplex or Half Duplex
    • Push or Pull
    • Different Roles of the "Server"
There's Always More to Learn
Back -