Lecture 1b: Networking

Packet switching

• OSI model

  • Purpose of physical, data link, network, transport, presentation layers
  • Which layers are used by IP

• Data Link Layer

  • Local Area Network (LAN)
  • Ethernet - service guarantees

• Network Layer

  • Internet Protocol (IP)
  • connectionless service
  • IP principles: survivable, decentralized design, routing
  • delivery guarantees

• Transport Layer: TCP & UDP

  • TCP
    • Connection-oriented service, full-duplex connections, reliable & in-order data delivery
  • UDP
    • Connectionless service and UDP’s delivery guarantees

• Understand the concept of layering in network protocols

• Clients and servers and services

• Transport endpoints (ports) vs. network endpoints (addresses)

• Data link addressing vs. network addressing: MAC address vs IP address

• Protocol encapsulation concept

  • Ethernet device driver: encapsulate IP within an ethernet packet
  • IP: encapsulates UDP or TCP packets within an IP packet