Network Models

  • Topology
    • How parts of a whole work together
  • Physical topology
    • Mostly related to hardware
    • How devices connect to form the physical network
  • Logical topology
    • How software connects to the network
    • How users/programs gain access to the network
  • Network operating system (NOS)
    • Controls access to the entire network
    • Required by client-server models

Peer-to-Peer Network Model

Peer-to-peer network diagram

  • OS of each computer on the network is responsible for controlling access to its resources
    • No centralized control
  • Computers form logical groups and users
    • Nodes or hosts
    • May share resources (and control access to them)


  • Simple configuration
  • Less expensive


  • Not scalable
  • Not secure by default
  • Not practical on a large scale

Client-Server Network Model

Client-Server network diagram

  • Resources managed by NOS via centralized database
    • In Windows it's Active Directory
  • Client
    • A computer making a request to another
    • Resources aren't shared directly between clients
  • Shared resources are on a server
    • Access controlled by domain database
  • NOS is responsible for:
    • Managing client data and resources
    • User, file, and network access

Advantages compared to peer-to-peer networks

  • Credentials assigned in one place
  • Shared resources are centrally controlled
  • Central place for debugging, diagnostics, and correction
  • More scalable

Computer Science Networking