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An Introduction
KVM Over IP Switches and Appliances
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In the last several years, a whole new
generation of Keyboard, Video and Mouse switching and remote control
systems have evolved. Unlike the traditional analog KVM switch,
which uses direct point-to-point wiring between servers, switch
hardware, and end user consoles, the digital keyboard, video and
mouse switch and appliances (KVMoIP) use conventional network
infrastructures running TCP/IP protocols to permit remote access and
control of computers.
Early KVMoIP product releases were dominated by only a few
solutions. Recently however, there have been wide variations of
digital product solutions released. This necessitates a clear
discussion of dKVM technology, how the product differ and where they
are best deployed. Here we will discuss the variations for GUI based
hardware, who offers the solutions and how administrators like you
are deploying these products. We will follow-up in future
newsletters with discussions of the access software, ASCII based
console access servers and most importantly, throughput issues and
deployment techniques any administrator will be faced with.
There are three types of KVMoIP solutions. These solutions include
the KVMoIP Switch, the KVMoIP Appliance and Hybrids (a digital
circuit embedded in an analog KVM switch). There are two primary
drivers in the evolution of these three dKVM technologies. First,
the technology needed to be engineered and introduced to the market.
Second, after initial engineering, the end user community offered
its input that is ultimately shaping how the industry is packaging
these products. See the sidebar on the history of dKVM for more
information on the evolution in this sector of the market.
KVM Over IP Switching (KVMoIP)was introduced to the market by
Avocent
Corporation in 1998 with the first release of the DS1800. The
DS1800 is a true switching device supporting eight analog computer
inputs and connected directly to your IP network via a 10/100 NIC.
Users accessing this switch can select one or more of the eight
inputs at any time and as many as eight independent users sessions
are supported in this device (See more on throughput in our next
newsletter). This is a enhancement of magnitude over analog KVM
where only one switched computer can be displayed at any time. And,
the DS1800 can be used as an
appliance as described below with and without certain
integration limitations. As of the writing and later edits of this paper, the
DS1800 is still the only pure dKVM switch available.
KVM over IP Appliances are designed to be connected to a single computer
or an analog KVM switch. The backend analog KVM Network can be of
any size, so the cost per port of a dKVM Appliance is distributed
over all analog ports on this type of KVM Network. Also connected to
your IP network via a 10/100 NIC, users accessing dKVM Appliance
select only one port at any time (with the exception of
Rose Electronics UltraLink)
and only a single independent user session are supported in these
devices. Also, a variation in the packaging of current dKVM
Appliances can be found in the
Raritan TeleReach II that can bring down the cost per port.
Originally, only two KVMoIP Hybrids were available offered by
Avocent Corporation and
Digital V6.
Today however, many more hybrid switches are being offered by both large
and small KVM switch manufacturers. The most intriguing are those from
Raritan Computers, Inc.
who offers three model variations. In general, the dKVM Hybrid limits
digital throughput with one exception - the Raritan Paragon II KVM switch
offering a new concept of integrating KVM Over IP into the base user
station of a high user throughput KVM switch system.
These devices typically offer a local
analog console in addition to a digital port that prepares the
analog signals for transmission over TCP/IP networks like the dKVM
Appliances.
Depending on the product, one, two or four digital data
paths are provided. Avocent offers the DSR Series which allow users to select
between sixteen analog ports
with one, two or four digital data paths (ddp). The four ddp DSR
model now offers analog console support. The latest Kaveman KVMoIP
switch from Digital V6 features a sixteen analog ports with six digital data
paths. The DSR also compares closly with the Raritan
Dominion KX
while the
Paragon II
can be deployed with multiple analog consoles and
sixteen independent KVM Over IP digital data paths
KVM over IP Software
features several methods of accessing a KVM over IP device.
Local consoles, dial-up and serial connections offer a backup - if and when
your network is down. Proprietary software offers the greatest video quality and in some
cases the highest degree of security. Alternatively, web browsers
and VNC clients can be used to access dKVM devices. Because of the
security, quality and technical variations of the access
methodologies, this is an entire paper in itself that will be
offered in future newsletters and technology papers.
A summary of KVM over IP in any form is an out of band solution
requiring no software to be loaded on the connected hardware.
Depending on the hardware solution and your particular deployment,
the out-of-band design assures you have BIOS level remote control of
computer hardware that is connected to the digital KVM Network.
KVM over IP Switches, Appliances and Hybrids are being
deployed in highly secured data centers where administrators want to
secure the hardware access to a few selected technicians while
assuring general users have access as needed. With lower aggregate
cost, dKVM Appliance and Hybrids are also being deployed in
satellite offices around the world. In addition, dKVM Appliances are
combined with proprietary analog KVM Networks as an economical and
“practical” solution. Combining dKVM Appliances with the latest
in hybrids allows your organization to seamlessly migrate from your
current analog KVMS system to the new dKVM technologies. The latter
presents the highest economies of scale.
For more detail on each dKVM product, their related cost and
personalities, please refer to our technical paper
KVM over IP (KVMoIP) Devices Demystified
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