What is a KVM Extender?

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 fiber 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 centers), 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 workplace

• Secure computers in safeguarded locations: protect them from damage, technical failures or major power outages

• Data access protection: prevent content theft or unauthorized network access by limiting software/hardware access.

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.

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/Fiber/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, fiber optic cabling, or an IP network:

• Optical fiber 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

KVM Matrix Switches (Connectivity over CATx, Fiber or an IP network)

KVM matrix switches are used to connect multiple users with multiple sources like PCs and servers. The term matrix derives from the fact, that users can access various different sources within one managed KVM network - creating a matrix of various switchable endpoints. KVM matrices usually provide a specific number of ports to connect all endpoints over a transmission medium which can be CATx or fiber, utilizing either a proprietary transmission protocol or IP. KVM matrix switches are usually also combined with KVM extenders to connect all related machines and users over small to large distances (CATx: usually < 150m; Fiber: >150 m < 20km). There is a large number of different types of KVM matrix switches varying from central, fixed-port switches to modular, card-based ones, or even zero-client based IP systems that do not require a proprietary central switching unit and provide greater scalability. There's a wide range of supported display, peripheral, and audio interfaces, such as analog VGA, SDI, Composite, digital DVI, DisplayPort, HDMI, USB 2.0/3.1, PS/2, serial formats such as RS232, Infrared, digital and analog audio and even more.

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 artifacts that degrade the high-resolution viewing experience. They are ideal for applications such as broadcast, high-end medical imaging, interactive digital signage, home theaters, and even industrial automation.

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 fiber connections. Some extenders come with a built-in de-skew option to compensate for skewing effects.

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 centers or industrial control rooms.

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.