Networking

Communicating between multiple hosts using a shared infrastructure consisting of nodes.

Participants

Nodes

• Switches/Routers: Routing decisions using addresses
• Repeater/Hub: Amplify signals

Hosts

Typically end systems connected to the network.

Classification

Public

Standardized options offered by service operators, like DSL lines, mobile telecommunications networks or hotspots.

Private

Exclusive for closed group of hosts. These often use public networks as infrastructure with a set of restrictions configured on top of them, in which case it is referred to as a virtual private network (VPN).

Core

Main connections structure.

Access

Facilitate access to core networks. Examples include WLAN or LAN.

Distance

• Personal area network (PAN): Linking devices via bluetooth (10m)
• Storage area network (SAN): For storage systems in data centers (100m)
• Local area network (LAN): Typical home/office network (10m - 10km)
• Metropolitan area network (MAN): Mostly deprecated due to LAN's (10km - 100km)
• Wide area network (WAN): Often using different technologies like IP or Ethernet (more than 100km)
• Global area network (GAN): World wide networks

Operations

Packet switching

Data is transferred in small packets independent of each other, which the internet operates on.

Circuit switching

Data routes between communication partners are permanently reserved.

Computer network vs distributed system

If the implementation matters it is called non-transparent and belongs to the computer network area. If the implementation plays no role it is called transparent and is part of the distributed systems area.