Communication Protocol Issues

• Message content [application layer]
  • Data content
  • Command content
• Message delivery
  • Addressing [data link, network, and transport layers]
  • Across a single link [data link layer]
  • Host-to-host [network layer]
  • Process-to-process [transport layer]
  • Order preservation [transport layer]
• Message transmission
  • Coordination [data link and physical layers]
    • Error detection and correction
    • Clock synchronization
  • Channel organization [physical and link layers]
    • Channel sharing
      • Time division multiplexing (baseband or broadband)
      • Frequency division multiplexing (broadband)
    • Point-to-point or broadcast
    • Simplex or duplex (point-to-point only)
• Media [physical layer]
  • Parallel/serial
  • Bit transmission
  • Bit encoding
    • Baseband (unmodulated)
    • Broadband (modulated carrier)