Auto MDI MDIX - Detailed Overview

Published on Updated on November 28, 2023

Media Independent Interface (MDI) and Media Independent Interface with Crossover (MDIX) are basically ports on a computer and a network switch, router, or hub, respectively. You can connect to them with the help of RJ-45 connectors and a fiber optic or a twisted pair copper cable. They are basically a type of Ethernet interface and an integral part of data transmission in a network. Choosing the right cable is important as the linking of transmission at both ends should be correct. So, what is Auto-MDI-MDIX? This post discusses the details regarding the Auto-MDI/MDIX feature, and how it impacts the cable selection process.

Auto MDI MDIX Feature

What is the Auto-MDI/MDIX Feature?

The MDI port transmission signals are sent to the ethernet network switch or router, while the signals transmitted from the router or switch or MDIX port are received in a crossover pattern to the workstation or MDI port. This means the input and output signals are reversed and this configuration straightaway eliminates the need for a twisted pair cable at the MDIX port. While most network devices do have both MDI and MDIX ports, computers usually have only MDI ports. The latter are connected to the router through a simple Ethernet cable, while MDI to MDIX connection is established through crossover twisted pair cables. To avoid this cable, the switch or router must have an MDI port. To avoid the complications between MDI and MDIX connectivity, the auto-MDIX feature was developed. The term auto implies automatic detection of the type of port. So, this feature identifies if a crossover or simple cable is required and switches between MDI and MDIX configuration accordingly. So, the type of cable used does not matter in terms if the correct port linking. Once a cable is connected, this feature does the rest. This feature may even detect the network speed and make the required adjustments automatically. In absence of this feature, if wrong linking is done, the transmission would certainly fail to go through or the network may even crash.

Impact of the Auto-MDI/MDIX Feature on Cable Selection

Ideally, the selection of the cable type largely depends on the type and size of your network. The auto-MDI/MDIX feature simplifies your cable selection process. So, you are free to choose a copper or fiber optic cable depending upon your network needs as this feature especially addresses the crossover linking problems. Cables on the external front look pretty similar, whether they are crossover or simple ones, and hence can create more confusion when linking. Most switches or routers have this feature as a default, while it may be disabled on others. The beneficial part of this feature in case you plan to upgrade your network is that it can be installed on ethernet media converters, and you can enable or disable the more as per your requirement.

If you are looking to upgrade your network in terms of geographical extension, speed, and connectivity, switching to fiber optics by using a media converter is a viable and affordable option. However, it is important to choose your cables and other network devices correctly and source them from a known and certified manufacturer and supplier. VERSITRON is a leading manufacturer and supplier of fiber media converters, Ethernet switches, modems, and various fiber network devices.

Rich Tull

Rich Tull
R.W. Tull is the President of Versitron, a leading technology company specializing in data communication and networking solutions. With expertise in Guiding network switches and media converters, R.W. Tull has played a pivotal role in driving Versitron's success. His deep understanding of these technologies has enabled the company to provide innovative and reliable solutions to clients. As a visionary leader, He ensures that Versitron remains at the forefront of the industry, delivering cutting-edge networking solutions that enhance data communication efficiency.
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