Network Switching

Hubs and Switches

Hubs and switches are different types of network equipment that connect devices. They differ in the way that they pass on the network traffic that they receive.

 

The term ‘hub’ is a piece of network equipment that connects PCs together.  A hub simply passes on (repeats) all the information it receives, so that all devices connected to its ports receive that information.

 

‘Switches’ control the flow of network traffic based on the address information in each packet.  A switch learns which devices are connected to its ports (by monitoring the packets it receives), and then forwards on packets to the appropriate port only.  This allows simultaneous communication across the switch, improving bandwidth.

 

In larger networks, a network switch provides better performance, reducing the amount of unnecessary traffic being transmitted across your network.

 

Network switches can prioritise and forward packets based on different Layers in a network – these are defined by the OSI Model.  Switches are typically divided into Layer 2, Layer 3 and Layer 4 switches.


 

VLAN

A virtual local area network (VLAN) is a concept of partitioning a physical network, so that distinct broadcast domains are created.  This is usually achieved at a network switch or router level, where devices can mark network packets through tagging, so that a single physical network route (/cable) may be used to transport data for various VLANs.

               

Benefit – To physically replicate the functions of a VLAN would require a separate, parallel collection of network cables and equipment separate from the primary network – the VLAN gets around this.

 

Vendors and Products

  • Netgear
  • 3Com
  • Cisco
  • HP
 
Networking