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

• 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)

Advantages

• Simple configuration
• Less expensive

Disadvantages

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

Client-Server Network Model

• 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