Vendor Content.

Classic KVM Or KVM Over IP: Part 1 - Basics, Advantages And Challenges

Classical KVM or KVM-over-IP: what is the perfect fit for your application? - A comparison in two parts.

Jochen Bauer, Head of Sales & Marketing at Guntermann & Drunck.

Jochen Bauer, Head of Sales & Marketing at Guntermann & Drunck.

Being deeply rooted in broadcasting, KVM systems provide an ideal basis for the flexible, distributed switching of computer signals. They are successfully applied in a wide range of applications such as OB vans, studios, post-production and broadcast control rooms as well as in processes from ingest to playout. For years, broadcast and IT applications have been merging more and more. KVM systems offer an excellent basis for operating various heterogeneous systems on a homogeneous user platform and thus gradually become the backbone of the entire IT infrastructure.

Generally, one distinguishes between classical KVM systems and KVM-over-IP. But what technology is the better choice for your application? What are the differences, what benefits and challenges do they have, and what should you look for when choosing a KVM system for your project? In this article we will take a closer look at classical KVM systems.

KVM As Backbone Of The IT Infrastructure

KVM systems enable you to remove the powerful broadcast computers from the production environment. For this purpose, computers are usually moved out of studios, editing rooms, and control centres and housed in access-protected and air-conditioned areas. From the equipment room, fibre optics, CAT cables or IP structures extend the computer signals back to the workplaces. Particularly with regard to the current pandemic, KVM allows users to be even further separated from each other by enabling them to work in other premises, while still getting full access to all the systems they need. Thanks to KVM, producers have uniform access to the most diverse systems. In other words, the entire production team still has access to the remote computer technology – in real time and at full performance.

Classical KVM – An Overview

The most important difference between classical KVM and KVM-over-IP is the type of connection technology. Classical KVM uses dedicated cabling meaning that a dedicated network is usually set up for these systems. This way, the available bandwidth can be optimally utilized without other network-capable devices taking up bandwidth for themselves. Producers benefit from optimum performance combined with best possible image quality and a perfect user experience. One should also keep in mind that thanks to the standard connection technology, a possibly already existing in-house cabling infrastructure can still be used or even be expanded. Last but not least, classical KVM systems ensure fully secure access thanks to the complete control of the transmission medium.

Classical KVM At A Glance
  • Optimum use of maximum bandwidths, as there are no other network-compatible devices requiring bandwidth
  • Total control of the medium for maximum access security
  • Dedicated connections and proprietary transmission increase data security
  • For smaller networks, classic KVM can be more cost-effective than KVM-over-IP™, depending on project requirements (e.g. few CONs and CPUs). It’s worth comparing.
  • Plug & play-capable and easier to handle for IT admins
  • Classic KVM achieves maximum efficiency and performance by not losing bandwidth for IP overhead.

KVM-over-IP – An Overview

KVM-over-IP, on the other hand, is established on standard IP-based networks and offers ideal solutions for working in network structures. Together with a series of IP extenders,  G&D’s ControlCenter-IP forms a powerful matrix granting any connected operator station access to any remote computer. While the network infrastructure takes over the transport of KVM-over-IP™ packets using network switches and routers, the ControlCenter-IP contributes the logic. Transmission takes place compressed via CAT cabling or optical fibres via standard IP-based networks on layer 3 – even beyond sub networks. (KVM-over-IP will be discussed in part 2).

The Video Signal – The Main Aspect Of KVM Transmission

One of the most important requirements for every KVM transmission – whether it is classical or over IP – is the video quality. The transmission of video signals must be pixel-perfect and as latency-free as possible, without sharpness reduction and at high performance.

Video transmission also constitutes the most important difference between the various classical systems. Some systems transmit the available information pixel-precisely and in real time. In these cases, transmission takes place uncompressed. Uncompressing KVM extender systems work as a kind of transparent intermediary between computer and workplace: Incoming information is output unaltered at the other end. Uncompressing systems require a high bandwidth in order to transmit the incoming video signals from the computer’s graphics card to the monitor. Transmission is pixel-precise, transparent and absolutely lossless. However, a higher video resolution also requires a higher bandwidth, which in turn can only be provided by a more powerful, more expensive system.

Our classic compressing KVM systems offer pixel-perfect transmission and use the company’s own compression method called High Dynamic Image Processing (HDIP). Thanks to their pixel-perfect video compression, these systems do not only ensure a very high video quality, but also offer many other advantages. By compressing video signals, the systems require a lower bandwidth and allow for more cost-effective components. Since they are also compatible with G&D matrices, the systems can be quickly and easily expanded at a later point. Due to the usually simpler cabling, they can also be applied more flexibly. HDIP uses multi-level compression logic while maintaining fully sharp images and colour depth. A key advantage is that the codex contains more compression levels than algorithms from other manufacturers and also works across frames. We are therefore able to leave the box of a single frame and look at several images in comparison. This method ensures that lower bandwidths of 1Gbit/s or 3Gbit/s are sufficient to ensure that video data reaches users pixel-perfect, latency-free and unerringly.

Perfect For Demanding Broadcast Applications – Sky Germany

In broadcast applications, where uncompromising image quality, pixel perfection and latency-free operation are essential, the pixel perfect compression method offers users significant advantages and a much better visual result compared to other “visually lossless” compression methods. It is ideally suited for demanding applications in OB vans during live productions, in post-production, in studios and in all control room applications supporting the workflow in broadcasting centres. A perfect example for this is Sky Germany’s broadcasting centre in Munich. Here, Sky opted for the use of classical KVM in order to integrate and further scale the already existing KVM infrastructure. Here, two classical KVM matrices from G&D have been used to form the backbone of the IT. This may, the computer equipment could be removed from workplaces and is now located in a central server room.

Optimally implementing the high demands on security, redundancy, workflow facilitation and collaboration of Sky’s individual production teams for live reports required a concept to set up production and operating computers fully redundantly. For this purpose, two completely mirrored, redundant matrix switch clusters, each consisting of a ControlCenter-Digital 288, were installed to provide redundant access to the various console and computer modules of the individual systems. If - in the event of a disruption – switching via one of the two matrices would not be possible, the second matrix will be used automatically. Due to all components being fully redundant, the production teams are able to perform their tasks at all times.

Additionally, the matrix grid function helps integrate two existing matrix switches to behave as an extension to the system. This function enables the bidirectional communication between systems and ensures optimal connections across the entire installation. It allows producers bidirectional and more flexible access to their computer equipment and supports individual production teams in working together across departments. This not only increases flexibility, but also improves collaboration for live reporting.

The control room, where everything has to run smoothly.

The control room, where everything has to run smoothly.

Advantages For Collaborating As Efficiently As Possible

In order to facilitate the creative work in Sky’s broadcasting and production centre and to make it as efficient as possible, all video and program control rooms as well as ingest, playout, the graphics department and several studios are now almost computer-free. Any computers are accessed remotely via classical KVM equipment. Therefore, the workplaces have been equipped with KVM console units for DisplayPort and DVI. To create multi-monitor workplaces, single-head CON units were bundled in pairs.

The result of the demanding IT installation and several months of technical preparations is rather impressive: Around 100 CPUs (computer modules) and 85 CONs (console modules) were connected to the two classical KVM matrices, resulting in the installation of around 40 km of CAT cables in Sky’s broadcasting centre. The KVM system has also been integrated into LAWO’s VSM broadcast control and monitoring system to ensure uniform control and to simplify multi-level, complex processes. Thanks to G&D’s IP-Control-API, the VSM controller communicates with the KVM matrix and can execute any switching commands such as simultaneous switching of different programme requirements or exchanging setups between several control rooms.

With their own production and broadcasting centre, Sky Germany has gained maximum flexibility and above all even more freedom for future in-house productions. Individual workflows have been improved, making everyday production easier for everyone involved. Implementing two classical KVM matrices enabled the removal and centralization of equipment and significantly reduced noise levels in studios and the various control rooms.

Whether Classical Or Over IP – G&D’s KVM Supports The Broadcast Workflow

Regardless of whether you choose classical KVM or KVM-over-IP for a specific project – our KVM matrix systems can be quickly and easily linked to original broadcast equipment, thus supporting an optimal and efficient broadcast workflow. Even with physically remote computers, producers have the right technology at hand at all times and can operate live cameras, video walls, control panels, mixing consoles and other input devices as usual.

For this purpose, the matrix systems can be controlled via network using the integrated IP-Control-API, e.g. to execute switching commands. This way, external control options can be added to any system-specific operating concept. For an easier start, we provide a remote GUI as graphical user interface, and it is possible to integrate our matrix systems into 3rd party control concepts such as KSC Core, VSM or Avid’s ProTools. Independent from any location, each computer can access the desired projection media and/or operator screens. In the perfect symbiosis between the IT and the broadcast world, the matrix can also automatically follow complex application processes.


Classical KVM systems have their own advantages and are the preferred choice for many broadcast projects. But whether you use classical KVM or KVM-over-IP, the more important point is: to be a safe investment for the future, systems must be adaptable and scalable. Only in this way they can adapt to changing conditions and be expanded as the system architecture grows. G&D put great emphasis on the compatibility of their systems and ensure that existing KVM systems can be scaled in a future-proof manner.

But when should you use classical KVM and when is KVM-over-IP the better choice? Unfortunately, there is no universal answer to this question as selecting KVM systems always depends on the individual project parameters and preferences. But for further insight, let’s take a closer look at KVM-over-IP in the second part of the article to be able to better compare the differences, challenges and benefits of both types of systems.