Summary

UDP

• unreliable datagram
• best-effort service
  • may be lost
  • delivered out-of-order
• connectionless
  • no handshakes between client and server
  • each segment handled independently
  • send with IP destination and port to
• Use by DNS, DASH, SNMP

Note

• Fast: no RTT delay (connection establishment)
• Simple: no state
• Small: Header size
• No congestion control

UDP server

UDP client

Multiplexing

• demultiplexing using 2-tuple:
  • destination IP
  • destination port