KVM: Horses for courses

KVM main image use
KVM setup at command centre in Hong Kong

With the use of IP networks to deliver AV services becoming more common, Hurrairah bin Sohail weighs up how end-users can make the decision between direct KVM and KVM-over-IP.

As with many other technology verticals in the AV industry, KVM is dealing with the increasing influence of IT. The core functionality of the  KVM extender is to allow people to operate computers and computer-based equipment at a distance, using screens and keyboards at their desks, even though the base units may be located tens, or even hundreds, of metres away; with no degradation in video quality or delay in interactive response.

Basic extenders work in pairs, connecting a single operator workstation to a computer on a point-to-point basis and these have delivered reliable service for many years. The next logical step is to add a KVM matrix switch to which all devices and operator workstations are connected. But there are two distinct types of KVM systems, direct KVM and KVM-over-IP, each is suited to different applications and has a separate set of features. In KVM-over-IP systems, content and control data is packetised and distributed to users over the in-house IP network at the same time as the network is used for other corporate functions. Direct KVM on the other hand makes use of a dedicated copper or fibre cabling network.

The demand for KVM-over-IP is growing in Asia. John Hickey, senior director of KVM business at Black Box, says: “We are seeing strong growth of high-performance KVM-over-IP – but from a low base, growing at 40% to 50% per annum. Proprietary direct-connect technologies such as our DKM family still represent the major share of the market. KVM-over-IP for server management is not a growth area.”

Rod Sommerich, regional sales director for Gefen, says: “We have been selling IP KVM and matrix solutions since before 2012. With the arrival of affordable IP management, we have seen an increase in demand for these KVM extenders and matrix solutions.”

Delving further, Sommerich identifi es particular sectors where KVM-over-IP has been gaining traction: “We have seen an increase in demand where the client needs to move the computer away from the workstation. Markets include medical, operations, post production, museums, broadcast, studios and simulation.”

Hickey adds: “Broadcast, industrial, financial and all types of control rooms would be key markets for KVM-over-IP. The main drivers are performance and flexibility. Customers seek high performance video, audio, USB device extension, fast switching and increasingly enterprise-quality management software to allow optimisation of workflows.”

Choosing KVM-over-IP may provide a number of advantages. Sommerich says: “Traditional crosspoint matrixes require a complex and expensive frame. Expansion of the system beyond pre-defined sizes is expensive and is limited in function. IP systems can be expanded incrementally in single nodes (in or out) to almost any size as long as there is a network port available. IP also allows distributed switching with industry standard IP switchers, and other applications can coexist on the same network so the infrastructure costs are vastly reduced.”

Daniel Ng, vice president of business development Asia Pacific for Adder, says: “The two main benefits for clients lie in its [KVM-over- IP’s] flexibility and scalability. Whereas analogue KVM systems required time and cost-intensive work to IT infrastructures, KVM-over-IP can easily be edited and adapted to accommodate current business requirements.”

So how can end-users decide between direct KVM and KVM-over-IP?

Samuel Recine, director of sales for Americas and Asia Pacific at Matrox Graphics, suggests: “If the IP-based infrastructure is already in place, adding KVM over existing IP could have ease of deployment benefits. Full 4K and multi-4K is already available over IP at very low latency.”

He continues: “I think that the major benefit of KVM-over-IP lies in the vendor-agonistic network gear for extension and switching. This drives down cost and it improves standardisation. It also provides the benefit of new applications – like proxy streams. And it provides a path forward for updating KVM capabilities without having to keep upgrading the middle part (the switch gear).”

Sommerich says: “The cost break-even between the traditional KVM matrix and the KVM-over-IP matrix is around 4x4 and the benefits of category cable cost and handling make the system easier to deploy, and more convenient to manage and maintain. IP is clearly a viable option in almost every application, because it can expand and adapt as the customer’s requirements change.”

Network decisions

Making the choice easier for the end-user is the fact that KVM-over-IP can be deployed with 1G networks. This means that the upgrade path for the end-user is not expensive and would not require a great deal of capital investment.

Sommerich says: “Gefen does not use high cost 10G infrastructure for its solutions, we provide exceptional results using 1Gb networks, even at 4K 60Hz. Our algorithms optimise content so the user receives high quality content and control with no perceivable latency.”

Hickey: “No, 10G is not needed. Typically 1G Ethernet is needed to connect receivers and transmitters at the edge. These switches may need to be connected by a 10G switch if multiple edge switches needs to be interconnected. It depends on the bandwidth needed. InvisaPC for example only generates 35-40Mbps when full motion video is being transmitted – so over 20 “connections” can share a 1G link with no congestion. Black Box’s Agility platform generates 1G per connection so it really needs 10G to interconnect switches.”

The talk of IP infrastructure brings us to the topic of latency. Hickey says: “Latency is a function of the design of the receiver and transmitters for a KVM platform plus the switching infrastructure. For KVM-over-IP achieving latencies of a similar level to direct KVM is straightforward – standard Ethernet Gigabit switches have latencies of less than 100 useconds – so key is the design of the receivers and transmitters (which is similar to direct connect KVM). Of course, this is assuming no network congestion which can cause network latency.”

Sommerich says: “The Gefen solution uses an intra-frame compression system which offers minimal latency.”

It seems that latecny is part and parcel of KVM and it is the manufacturer’s job to make sure that it remains imperceptible. This is usually accomplished with the help of compression algorithms.

Hickey says: “Compression helps reduce the bandwidth need to see a connection over the IP network. The less the bandwidth, the lower network requirements are. There are constant improvements on compression with trade-offs on visual quality and network bandwidth is constantly being optimised.”

Recine says: “Advanced video codecs, optimised to offer ultra-low latency are being driven, in part, by the needs of the high-performance KVM market. Matrox’s new Extio 3 KVM-over- IP product borrows these new advanced video codecs and, combined with other optimisations for the I/O as well. This means that we can offer 4:4:4 4K60 at sub 50ms latencies over IP. This is an important number because at that speed, latency is unperceivable to the overwhelming majority of users.”

IT departments can also do their part to ensure latency is kept low.

Jason Fitzgerald, product manager at Gefen, says: “Firstly, using interlaced sources can add additional delay as the input must be converted to progressive before encoding and network transmission. Likewise, choosing an interlaced output with a progressive source can also add latency. In addition to this, networking bandwidth saturation can affect packets from arriving to their destination in a timely fashion. Video over IP solutions can be bandwidth intensive, especially with 4K content, and segregating video traffic from other network activities is a good practice.

This can be done by setting up a VLAN to host all the AVoIP network devices. Other methods include setting up QoS rules to prioritise the AVoIP packets/ports/etc. over all else. These do have implications on existing networks that the AVoIP solution is being deployed on, so the appropriate solution should be discussed with onsite IT administrators, if available.”

Jochen Bauer, marketing director at Guntermann & Drunck, says: “The important steps to ensure latency free operation via KVM- over-IP are to provide suffi cient bandwidth and avoid network disturbances. Therefore the easiest solution is the setup of a dedicated IP network solely for KVM purposes.”

Hickey adds: “Good network design with edge switches selected to cope with individual receiver and transmitter bandwidth requirements is essential. Then if edge switches need to be interconnected,  the use of suitable (often 10G) switches to interconnect are required. Also, if the KVM-over-IP platform selected uses multi-cast streams such as Black Box’s Agility product, then networks must ensure all switches support IGMP snooping to allow pruning of multicast streams.” Finally, as with all conversations about shifting technology to IP networks, we come to the consideration of security.

Sommerich: “If signals can be opened in software such as VLC or QuickTime, the information and security could be compromised. Gefen’s solution uses AES128 bit encryption. Our system has been deployed in many secure environments including military, security, gaming, stadiums, and broadcast, all of which closely guard the security of their content.”

Hickey says: “KVM-over-IP products have the same security needs as most IP based equipment. Ensure that all protocol ports are locked down and default username/passwords are changed to strong, non-obvious options with regular password changes. A key aspect is to ensure all connections use strong encryption – such as 128-bit AES. Some customers use KVM-over-IP on a private network to maximise security with a firewall to link to the outside world (if that is required).”

He continues: “Black Box has put these security aspects of KVM-over-IP at the centre of its design and added security event tracking in our Boxilla system management platform. Boxilla tracks failed login attempts and unauthorised connection attempts to allow IT managers to be aware of potential hacking events. This is an area we will be investing more resources in future releases.”

It seems staying with direct KVM may be the right move if security is your main concern. Terence Teng, managing director for IHSE APAC: “An important benefit offered by KVM switches lies in the security they offer. Locating computer and other source equipment in a safe and secure room prevents physical access to the content stored on it. USB ports, hard drives and external network connections cannot be accessed, so data cannot be removed without authorisation. Without an entry point, it is harder for viruses to be maliciously inserted. Direct KVM systems use proprietary compression algorithms to transmit data over dedicated cabling, making it harder to electronically access and make use of those signals and consequently much more secure.”

He continues: “The security of a KVM-over-IP system can be breached if the internal network is compromised, and this can be done eternally via internet connections. So housing computing equipment in an on-site secure location is rendered ineffectual.”

Moving forward it seems that both technologies will exist in parallel. It is a matter of choosing horses for courses. Teng says: “This [KVM-over-IP replacing direct KVM] is unlikely, due to security concerns and the need for latency-free video distribution and user response. Direct KVM can support high bandwidth video transmission and the instant response needed for interactive user response. This will become more critical as new types of immersive AV installations are introduced, particularly gesture, camera-based recognition and AR and VR.”

Hickey says: “I would not expect this to be the case over the next five years. KVM-over-IP has a long way to go to completely replace direct KVM. It has advantages but it will take time for some customers to get comfortable with it.” Sommerich says: “IP is not necessarily required for smaller systems, while it does provide a foundation for future growth. We will see a segmentation within the market as each project or application decides on the solutions they prefer, with large and medium projects selecting Video and KVM-over-IP solutions based on cost, fl exibility, expandability, manageability, ease of integration, and of course, convenience.”