network-1 4 layer internet model

4layer model

• application
• transport 
  • tcp: transmission control protocol
    • enable correct in-order delivery of data, running on top of the network layer service.
  • udp: user datagram protocol
• network
  • packet：data、from、to
  • network->link
  • ip
• link
  • source end-host  -- router -- router -- ... -- destination end host

7 layer osi model

• application
  • application 
  • presentation
• transport
  • session
  • transport
• network
  • network
• link
  • link 
  • physical