Connectionless vs. Connection-oriented

• CONNECTIONLESS (Internet, TCP/IP)
  • Subnet inherently unreliable
  • Provide only send/receive without guarantees
  • Let hosts do the work (at Transport layer)
• CONNECTION ORIENTED (X.25)
  • Establish connection
  • Negotiate Quality of Service (QoS)
  • In-sequence guaranteed delivery
  • Let network do the work