Networking hubs are central components of local area networks (LANs). To understand the role of networking hubs, a basic understanding of LANs is required. Whenever one or more computers are networked together, a LAN is created. A LAN can be vital at work, but it can also be useful at home. The purpose of joining computers together in a LAN is to share resources like files, a printer, a scanner, or Internet access.
There are four components in a basic wired hub network:
Ethernet wire: This is the physical cable that links the computers together, enabling them to talk to each other. The Ethernet cable, also called twisted pair, or 10-Base T, plugs into a network card located in each computer on the LAN.
Network Interface Cards (NICs) : One of these cards goes into a vacant slot inside each computer. The back of the card features a port for one end of an Ethernet cable. Newer computers normally have a networking card built-in.
Networking Hubs: The networking hub is a junction box with several ports in the back for receiving the Ethernet cables that are plugged into each computer on the LAN. With Ethernet cables going from each NIC to the hub, all computers are connected to the hub.
Networking Software: Most operating systems today come with networking software built-in, but the software is also available from third parties. The software works with the hardware to create a networking environment on each computer, allowing the user to see shared files and recourses. It also allows for administration of the network.
With a group of computers wired to the hub and the software installed, the computers can talk to each other. Networking hubs will broadcast all traffic that comes through the hub to all machines or nodes connected to the LAN. Each computer/node on the LAN will have its own address, called a MAC (Medium Access Control) address. Each node will ignore any traffic not addressed to its MAC address.
Networking hubs are simple devices that are fine for home use in most cases, but not considered optimal for workplace environments. Networking hubs can only operate in half-duplex mode -- a computer cannot receive and send transmissions at the same time. Another drawback is that networking hubs broadcast traffic indiscriminately to all machines on the LAN. This opens the door to security issues, making it easy to use so-called "packet sniffers," for instance, to snoop on all network traffic.
An alternate to networking hubs is to use networking switches. Switches fill the same function as hubs but operate at faster speeds due to full duplex functionality. This allows computers on the LAN to send transmissions as they are receiving them. Furthermore, switches do not broadcast all traffic to all machines, but send information to a specific MAC address. This not only makes for a somewhat more secure network, but also cuts down on bandwidth waste.
Yet another option, for those with cable modem or DSL service, is a broadband router with built-in switch capability. This eliminates the need for a hub or switch, as the router joins the LAN through the Internet. These routers also feature firewalls and filtering capability to increase security.
Networking hubs have all but been phased out with switches becoming more reasonably priced. A 5-port switch can sell for as little as US$30 or less. Generally speaking, the more ports to be connected, the more expensive the device will be.