Ethernet Back to Basics

Ethernet cable is a common type of network cable used with wired networks. Ethernet cables connect devices such as PCs, routers, and switches within a local area network. ... If a network cable is too long or of poor quality, it won't carry a good network signal

What is an Ethernet cable?

Ethernet cables are one of the most popular network cables and typically serve as a stable connection to a building’s Internet service. You would have definitely seen these colorful cables while connecting a computer to the Internet. It’s hard to imagine why these network Ethernet cables would be necessary, in an age where WiFi has been ingrained so fully into our lives. But, the stable connection they provide often surpasses the capabilities of WiFi

Ethernet uses Carrier Sense, Multiple Access with Collision Detection (CSMA/CD), to transmit frames from one device to another. In simple words, Carrier Sense is the detection of the network and any signals being transmitted so a device knows when it’s clear to send

Multiple Access describes the fact that all devices on the network receive all the frames and check the destination address. Collision Detection is the ability for a device to recognize that it has attempted to transmit information at the same time as another device, cease transmitting and retransmit again when it is clear to send. These retransmits use a random pause and retry to prevent devices from continuing to collide.

Metcalfe’s first Ethernet drawing with just a few devices was a fairly practical one. As the number of devices trying to transmit on a single network segment increased, collisions increased, networks became congested and transmission slowed down. To reduce congestion, network segments needed to be split into multiple segments that share information with each other. This is where switches come in.

Ethernet switches pick up every Ethernet transmission and forward it over the appropriate segment (i.e., link) to the destination address. This is what allows multiple devices on a network to communicate simultaneously

With Ethernet switching, came the ability to send and receive data at the same time using full-duplex Ethernet. Since devices in a modern switched network only communicate with the switch and not each other, there is no longer the need for most devices to detect collision

What does an Ethernet cable look like?

Ethernet cables come in many sizes. These cables could easily run from a second storey bedroom to a basement family room if necessary. An Ethernet cable may look similar to a phone cable, but the ends are typically larger and the cables themselves hold more material within.