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What is a KVM Extender? USB/HDMI/VGA/DVI/DisplayPort over CATx/Fibre/IP

What is a KVM Extender?

Black Box Explains

KVM Extender definition

KVM extenders are devices designed to increase the distance between a keyboard, monitor and mouse (KVM station) and a computer. Since PS/2 and USB keyboard and mouse protocols are only designed to run a distance of about 5-10m, and digital video signal quality is typically starting to deteriorate beyond about the same cable length (depending on the type of cable and interface), KVM extenders are a convenient solution to transmit these signals over long distances up to 150m (CATx) or even farther via fibre or IP connections. The main purpose of KVM extenders is to provide point-to-point computer extension and scale the access to computers from remote locations (e.g. secure data centres), ultimately helping to increase productivity workflow and workspace ergonomics.

If you are looking for info on KVM Switches, visit What is a KVM Switch?

What is a KVM Extender used for and when do you need one?

KVM extenders play an important role in overcoming bandwidth limitations of traditional VGA, HDMI and DVI cables, and distance limitations of the PS/2 and USB protocols. KVM extenders are used for a range of applications such as:

  • Remote PC access: enable remote high-speed KVM access to a single computer at HD display resolutions
  • Multi PC access: control multiple remote computers with a single set of peripherals for an extended desktop experience
  • Improve workspace ergonomics: reduce noise and clutter at the work place
  • Secure computers in safeguarded locations: protect them from damage, technical failures or major power outages
  • Data access protection: prevent content theft or unauthorised network access by limiting software/hardware access.

Find out more about why extending KVM is relevant and why it is used throughout a wide range of applications in almost all sectors. If you are not completely sure whether KVM extension is what you need and KVM switching might be more appropriate for your application, visit this article on KVM Switching vs. KVM Extension to find out more.

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What Type of KVM Extender do you need?

While all KVM extenders are used to connect users to their computers, there are a wide variety of customer needs and important features to look for when purchasing a KVM extender. In order to find the best KVM extender for your configuration here are the major questions to consider in advance:

  • What video signals do you need to extend?
  • Do you need to extend signals for one screen (single-head) or multiple screens (multi-head)?
  • What types of peripherals do you need to extend (USB HID, USB 2.0/3.0, audio, serial, etc.)?
  • What distances do you need to cover between the users and the computers?
  • What transmission medium will connect the users and computers (CATx/Fibre/IP Network)?

Types of KVM Extenders

There are different types of KVM extenders that are capable of transmitting various signals: VGA, DVI, HDMI, DisplayPort video signals, as well as keyboard and mouse, transparent USB, digital or analogue audio and serial formats like RS232.
KVM extension works over CATx cabling, fibre optic cabling, or an IP network:

  • Optical fibre KVM extenders are ideal when there is a need for an increased signal range (between buildings for example), for applications that require enhanced network security, for transmission of uncompressed high-bandwidth signals (4K60), or when your network configuration requires immunity from electrical interference (galvanic isolation)
  • KVM over IP extenders are preferred for applications where connectivity needs to be established across vast distances, where scalability of the system is crucial (KVM switching), or it is preferable to extend over an existing LAN infrastructure or even the Internet
  • CATx KVM extenders are perfect when you need to extend up to HD video and peripheral signals up to 150 m; CATx transmission is also the most cost friendly option

HDMI KVM Extenders

HDMI KVM extenders provide HDMI and USB signal extension over long distances without compromising video quality. These extenders offer low latency or even real-time transmission without delays and compression artefacts that degrades the high-resolution viewing experience. They are ideal for applications such as broadcast, high-end medical imaging, interactive digital signage, home theatres, and even industrial automation.

Find out more about Black Box HDMI KVM Extenders

VGA KVM Extenders

VGA KVM extenders are capable of extending up to 1920x1200 VGA signals over distances of 150 m (CATx) or even farther over fibre connections. Some extenders come with a built-in de-skew option to compensate for skewing effects.

Find out more about Black Box VGA KVM Extenders

DVI KVM Extenders

DVI KVM extenders are designed to overcome the distance limitation of DVI cabling. Digital KVM extenders are ideal in critical applications where reliable digital image quality and fast switch-over of redundant hardware are required, for example in broadcast playout centres or industrial control rooms.

Find out more about Black Box DVI KVM Extenders

DisplayPort KVM Extenders

DisplayPort KVM extension technology supports uncompressed transmission of up to 4K60 video signals. This helps to access high-performance graphical workstations and critical video processors from secure and temperature controlled equipment rooms while maintaining the same user desktop experience for editors, 3D artists and control room operators.

Find out more about Black Box DisplayPort KVM Extenders

What is the best KVM Extender to buy?

If you are wondering which KVM extender you need, and what is the best KVM extender to buy for your configuration, visit our KVM Extender Buyer's Guide page. Find recommendations, suggestions and all the important features you should look for when purchasing a KVM extender.

What to know more?
Download our whitepaper:
Complete Guide to KVM Extenders & Switches

Download our Complete Guide to KVM Extenders & Switches and get to know more about:

  • How KVM extenders work, and why they are making lives easier for both PC users and administrators
  • The most common mistakes made when purchasing KVM extenders
  • The major KVM extender applications
  • Essential tips for selecting a USB or KVM extender
  • KVM switching vs KVM extension
  • AV Extension vs KVM Extension