How Ethernet Works

Ethernet is a networking technology that allows computers and other devices in the same network to communicate with each other. Unlike wireless communication, signals pass through wires in an Ethernet network. This is the type of networking behind Local Area Networks (LAN), Metropolitan Area Networks (MAN), and Wide Area Networks (WAN). As the demand for faster networking speeds continues to rise, Ethernet technologies also continue to reach new heights. In its earlier days, the Basic Ethernet standard was widely implemented, but the speed that it was crawling at was a slow 10Mbps. The speed of Ethernet later significantly improved to 100Mbps with the Fast Ethernet standard. Although Fast Ethernet is still the most common standard in use today, standards supporting faster speeds, such as the Gigabit Ethernet, which can handle up to 1000 Mbps or 1Gbps, and the 10 Gigabit Ethernet are already being implemented, especially in large industries.

How Ethernet Works

Each device in an Ethernet network has an Ethernet card, more commonly known as the NIC (Network Interface Controller). These devices are referred to as nodes, and they talk to each other using protocols. In the context of networking, a protocol is a language of communication between connected devices. Nodes communicate through frames, chunks of information that nodes send as short messages. Frames carry information that a node is sending to another node. If protocol is the language, frames are the sentences. The Ethernet protocol specifies the set of rules for constructing frames, and each frame has a destination and a source address to identify the sender and receiver of a frame. No two nodes have the same address. The devices are connected to each other through Ethernet cables, also referred to as the medium.

Signals tend to attenuate as they travel through a cable. Some signals may even get lost if the cable is too long. To retain quality, the signal needs to be amplified. In an Ethernet network, these amplifiers are called Repeaters. Repeaters, or signal boosters, are electronic devices that amplify and then retransmit a signal. These repeaters are installed at certain intervals in an Ethernet network.

Colliding Signals

A common problem in Ethernet networks is the collision of signals, which happens when two or more computers send data at the same time. The CSMA/CD (Carrier Sense Multiple Access with Collision Detection) effectively deals with this network dilemma. With Carrier Sense, the computer checks whether the wire is being used before it sends information, which is applied when many computers use the same connection, thus the Multiple Access. When the devices in a network send information at the same time, this information will collide and will not be sent successfully. Collision Detection is the ability of the devices in the network to detect that other devices have also sent information to other devices. When this happens, said devices will wait for a random amount of time, then try resending the information.

Ethernet Cables

Ethernet cables bind together all the devices in a network. There are currently two types of Ethernet cables available: Twisted Pair and Fiber Optics. The type of cables used determines the performance of the network.

Twisted Pair Cables

Twisted Pair Ethernet cables are made of copper wires twisted in pairs and bundled together in a plastic cover. The ends of the cables are sealed in an RJ45 connector. Twisted Pair cables have been around since the beginning of Ethernet networking, and they are classified according to several categories.

The first cable used in an Ethernet network was the Category 1 cable, which was widely used in the 1970s. Also known as the coaxial cable, this cable is composed of twisted telephone wires wrapped in a plastic jacket. Subsequent iterations had improvements in frequencies and performance. However, it was not until 1995 when there was a significant leap in frequency and speed. Category 5 cables have a frequency of over 100MHz and a much faster speed of 100Mbps. It was not long before the Category 5e or Cat 5e cable was introduced, pushing the speed to 1Gbps. The Category 6 cable came out at the beginning of the 21st century. Running at 250MHz, Cat 6 cables can deliver data at 1Gbps over 330 feet and can go as fast as 10Gbps at over 150 feet. Cat 6 cables also have shielding to reduce interference. An enhanced Cat 6, the Cat 6A cable runs at 500MHz, delivering 1Gbps over 330 feet. Category 7 is next in the cable ladder, with a higher frequency of 600MHz and outstanding performance of 10Gbps over 330 feet. To enhance the isolation, each pair of wires is shielded, and another shield covers the entire bundle of wire, further reducing interference. The Cat 7 cable was enhanced to Cat 7A, which carries 1GHz at an astonishing speed of 40Gbps over 165 feet. The list is getting longer, with the latest addition to the group, the Category 8 cable, running at the highest frequency of 2GHz and a speed of 40Gbps. Cat 7 and Cat 8 are mainly used in server rooms and data centers, where top-grade speed is required.

Fiber Optics Cables

Nowadays, fiber optics has been taking the limelight in the networking field. Made of fiberglass, fiber optics can deliver much better performance than traditional copper wires. Fiber optic cables can handle 10Gbps of data over long distances of 1000-6000 feet. This eliminates the need for signal boosters. Fiber optics are also immune to interferences, unlike copper cables, since they carry light instead of electricity. The signal is therefore more reliable in fiber optic cables.

Benefits of Ethernet

Ethernet is still widely implemented all over the world, despite the rise of wireless communication. With newer technology developed over time, Ethernet continues to cater to the needs of most networkers, especially their need for speed. Ethernet is also more reliable than its wireless counterpart. Since data travels through cables and not thin air, there is less chance for interruption from radio frequencies and other signals. Reliability, efficiency, data security, and faster speeds are just some of the many benefits of an Ethernet network, which is still widely used in today’s networking spaces.

About the author

Glynis Navarrete

A freelance blogger who loves to write about anything related to technology. Born and raised in the Philippines and worked in Singapore for eight years as Technical Support for a wide range of IT equipment. Took a dive into the world of freelancing and now enjoying doing what I’m passionate about while not losing touch with technology.