The network is the computer

Conventional layers in a computer:

• Hardware: CPU, Memory...
• Architecture: x86, Sparc...
• Operating system: NT, Solaris...
• Language support: C, Java...
• Application: dbms...

Compare with a network:

• Hardware: Computers and communication media
• Architecture: standard protocols (OSI)
• Operating system: microkernels (Mach)
• Language support: heterogeneous platforms (NT, Linux)
• Application: client-server, peer-to-peer

Services: Each layer provides to layer Above