How Does an Ethernet Switch Work?

Identification

When traffic increases on a network, a switch can divide extremely large networks into smaller ones without affecting the performance of the network. Larger networks can develop increased amounts of traffic as more computers are added. The switch works as a filter to control the usage of the devices on the network. It is an external device that is connected to the devices on your network. It works to inspect the packets and data that is communicated on your network between the devices that you have connected. This device can benefit the network because it works to control the bandwidth of the network and helps to keep it stable.

Types

There are two types of Ethernet switches: a "cut-through switch" and a "store-and-forward" switch. A "cut-through switch" forwards the packets before they have been received. This helps reduce the amount of time that the switch takes to operate, however, this method is not very reliable. This method has been known to have packets that have been corrupted, thus affecting the productivity of the network. A "store and forward" switch sends the packets to a station where there are held temporarily until they are needed. The packet's information is verified before it is forwarded to the network. This type of switch is preferred in network settings where there are high error rates. This type is also preferred as it proves to be more reliable because the packets are completely analyzed before they are forwarded.

Function

The switch is added to the network by plugging various devices into the ports on the switch. When the switch gets the first bit of information from the first device, such as your computer, it reads the MAC address of that device. The MAC address is the media access control number. This number is an ID number that is assigned to most network adapters and is preset by the manufacturer. Once this number is read, it is recorded in memory by the switch. Next, the switch attempts to look for any other devices on the network by sending out packet requests of information. Once another device gets this packet, it sends out a signal to the switch to acknowledge the request. Now the MAC address of this device is recorded. Each time these packets are sent, the information is "time stamped." The switch works to filter this information that is communicated among all of the devices. The switch has enough memory to retain this information in its memory bank.