Networks: OSI Reference Model International Standards Organization Open Systems Interconnect (OSI) Reference Model Networks: OSI Reference Model
Application A Application B Application Layer Application Layer Presentation Layer Presentation Layer Session Layer Session Layer Transport Layer Transport Layer Communication Network Network Layer Network Layer Network Layer Network Layer Data Link Layer Data Link Layer Data Link Layer Data Link Layer Physical Layer Physical Layer Physical Layer Physical Layer Copyright ©2000 The McGraw Hill Companies Electrical and/or Optical Signals Leon-Garcia & Widjaja: Communication Networks Figure 2.6 Networks: OSI Reference Model
Application A Application B data data ah data ph data sh data th data Copyright ©2000 The McGraw Hill Companies Leon-Garcia & Widjaja: Communication Networks Figure 2.9 Application A Application B data Application Layer Application Layer data ah Presentation Layer Presentation Layer data ph Session Layer Session Layer data sh Transport Layer Transport Layer data th Network Layer Network Layer data nh Data Link Layer Data Link Layer dt data dh Physical Layer Physical Layer bits Networks: OSI Reference Model
HTTP Request TCP Header IP Header Ethernet Header Frame Check Sequence Header contains source and destination port numbers TCP Header Header contains source and destination IP addresses; transport protocol type IP Header Header contains source and destination physical addresses; network protocol type Frame Check Sequence Ethernet Header Copyright ©2000 The McGraw Hill Companies Leon-Garcia & Widjaja: Communication Networks Figure 2.15 Networks: OSI Reference Model
Networks: OSI Reference Model OSI versus TCP/IP Figure 1-21. The TCP/IP reference model. Networks: OSI Reference Model
DCC 6th Ed., W. Stallings Figure 1.11 OSI versus TCP/IP DCC 6th Ed., W. Stallings Figure 1.11 Networks: OSI Reference Model
Networks: OSI Reference Model Seven OSI Layers Networks: OSI Reference Model