How does ethernet work

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Some of you may have heard of the term Ethernet. However, most of them do not know what is behind it. It is absolutely not a new invention and is becoming increasingly important. What is hidden behind the term and why it is so important, we reveal here.

What is ethernet

Data can be transmitted with the Ethernet

Through an ethernet you can Data is transported from one device to another in a closed network become. This requires ethernet-compatible devices and a connection between them. In this way, for example, photos can be sent from the computer to a Smart TV or documents from a PC to a printer, an external hard drive or another computer.

Necessary for this transmission and connection is aEthernet cable - this is better known under the term LAN cable. The cable is connected to a device and to the router. The router serves as an interface and connects the devices to a closed network. This form is already relatively widespread as a home network. However, it is much better known in offices or in companies.

How does the ethernet work?

An Ethernet basically consists of two component groups: the "Data Communication Equipment" (DCE) and the "Data Terminal Equipment" (DTE).

Data communication equipment includes all of them Devices that receive and then forward data can. For example, routers, hubs and switches. They serve as interfaces and as a connection between the individual elements of the data terminal equipment. This is nothing more than the end devices that receive the data from the DCE via the Ethernet and, in turn, can send it to other end devices via the DCE.

Ethernet cable

This is particularly interesting for large companies

In order for an Ethernet to work and for the data to be able to be sent within a closed network, the data communication equipment is connected to the data terminal equipment via a suitable cable be. The correct name for this is Ethernet cable. Most, however, know it as a LAN cable - where Local Area Network stands for “local area network” or “local network”.

The initial ethernet was a thick coaxial cable. Therefore, the form was initially called "ThickEthernet" (thick Ethernet). Over time, the cables became thinner and so the shape was given a new name: "Thin Ethernet". Meanwhile, however Telephone cables made of copper as a transport medium proven for the data between distribution and terminal devices. For longer distances, however, fiber optic cables are used.

From the direct connection to the hub

During the early days of Ethernet, computers were connected directly to one another via a cable harness. On the one hand, this continuous cable harness made it difficult to track down defects. On the other hand were sent data distributed to all connected devices. This in turn could lead to a data jam and also made it more difficult to restrict access to data within the network.

The introduction of hubs brought advantages. The devices in the Ethernet were no longer directly with each other, but connected to each other via an interface. This makes it easier to detect defects along the cable. You can also Data is transported from a sender to a recipient in a targeted manner - without being available to the entire network. This makes securing or restricting access easier and less expensive.

The directed data transmission also reduces the risk of data congestion within the local network.

The history of ethernet

Robert MelanctonMetcalfe is considered to be the inventor. It was developed over several years at the Xerox PaloAlto Research Center. Metcalfe laid an important foundation stone in one Memo from 1973 - this is where he first mentioned Ethernet. However, the function and structure were previously only available as a sketch. The idea goes back to the ALOHAnet. A radio-based network protocol from Hawaii.

However, several years passed before the first functional Ethernet and its spread. First Late 1970s and early 1980s Increased efforts have been made to integrate Ethernet as the standard.

Improvements followed by:

The right cables ensure a secure connection

Hubs: The hubs already mentioned left shorter and separated connections between devices too. The data transfer can be carried out in a more targeted manner. In addition, errors can be found and corrected more easily.

Switching: Classic Ethernet allows several devices share a cable to use. Experience has shown that this method is successful as long as the volume of traffic - i.e. the amount of data transported - is comparatively low. Otherwise, traffic jams can form with this technology. These are also known as collisions. Switching stores data packets and thus reduces the risk of these collisions.

Ethernet flow control: The - in German - "flow control"prevents collisions during data transmission by specifically pausing the transport. The system can be compared with a traffic light intersection. The flow of traffic is controlled so that everyone can pass as safely and quickly as possible. However, this technology is no longer widespread today. However, it can still be used optionally.

Introduction of copper and fiber optic cables: The introduction of thinner copper and fiber optic cables made the technology more reliable on the one hand. On the other hand, you can use special copper cablesnot only transfer data, but also energy become. The devices in the Ethernet can also be supplied with power via this. The main advantage of fiber optic cables is that they have one fast and wide data transport enable. They are therefore preferably used in larger companies to cover longer distances.

Advantages of the Ethernet

Private users in particular are mostly unfamiliar with Ethernet and may be wondering why it is not simply being replaced by WLAN. After all, it is wireless and very easy to install. However, Ethernet also has some advantages over WLAN (Wireless Local Area Network).


  • Independence: Whether the internet and WiFi connection is working or not, the technology allows continuous data transfer. This makes it more reliable overall and is a good choice, especially in companies.
  • Security: there the ethernetworks independently of the Internet and WiFi and relies on wired connection, it can be made more secure. Protection is easier, especially with sensitive content within companies.
  • Inexpensive: The implementation of an Ethernet is extremely inexpensive compared to other systems.
  • Further development: Not least because of its numerous advantages and widespread use, the Ethernetcontinuously developed. Again, that is a benefit.

Disadvantages of the Ethernet

A potential disadvantage of the Ethernet is that it does not control the exchange of datacollisions can still occur. This can cause the data transfer to stall or be restricted.

Julia is editor and proofreader for the blog of Biteno GmbH. She mainly writes on technical and business topics - so that they can also be understood well by non-IT people.
/ by Julia UllrichKeywords:Data, ethernet, fiber optic cables