3. Chapter 3: Networking and Internetworking

3.4. Packet Transmission

  • Messages
    • logical unit of transmission in computer networks
    • Sequence of data items of arbitrary length
  • Message is subdivided into packets. 
  • Packets
    • Sequence of binary data (an array of bits or bytes) of restricted length.
    • Contain addressing information to identify the source and destination computers.
  • Packets of restricted length are used:
    • Each computer in network can allocate sufficient buffer storage to hold the largest possible incoming packet.
    • To avoid the undue delays that would occur in waiting for communication channels to become free if long messages were transmitted without subdivision.