Packet Switching

• About 40 years old

• First large deployment was the ARPANET

• • AT&T thought it would not work!

• When a host generates a message, it must:

• • Break the message into packets
  • • Each no greater than a given Maximum Transmission Unit (MTU)
  • Add a routing header to the beginning of each packet
  • Transmit each packet

• In order to receive a message, a host must:

• • Wait for all of the message’s packets to arrive
  • Strip the header off of each
  • Put them back into order