Black Box Explains...Digital Visual Interface (DVI) connectors.
DVI (Digital Video Interface) is the standard digital interface for transmitting uncompressed high-definition, 1080p video between PCs and monitors and other computer equipment. Because DVI accommodates both analog and digital... more/see it nowinterfaces with a single connector, it is also compatible with the VGA interface. DVI differs from HDMI in that HDMI is more commonly found on HDTVs and consumer electronics.
The DVI standard is based on transition-minimized differential signaling (TMDS). There are two DVI formats: Single-Link and Dual-Link. Single-link cables use one TMDS-165 MHz transmitter and dual-link cables use two. The dual-link cables double the power of the transmission. A single-link cable can transmit a resolution ?of 1920 x 1200 vs. 2560 x 1600 for a dual-link cable.
There are several types of connectors: DVI-D, DVI-I, DVI-A, DFP, and EVC.
DVI-D (digital). This digital-only interface provides a high-quality image and fast transfer rates between a digital video source and monitors. It eliminates analog conversion and improves the display. It can be used when one or both connections are DVI-D.
DVI-I (integrated). This interface supports both digital and analog RGB connections. It can transmit either a digital-to-digital signal or an analog-to-analog signal. It can be used with adapters to enable connectivity to a VGA or DVI-I display or digital connectivity to a DVI-D display. If both connectors are DVI-I, you can use any DVI cable, but DVI-I is recommended.
DVI-A (analog) This interface is used to carry a DVI signal from a computer to an analog VGA device, such as a display. If one connection is DVI and the other is VGA HD15, you need a cable or adapter with both connectors.
DFP (Digital Flat Panel) was an early digital-only connector used on some displays.
EVC (also known as P&D, for Plug & Display), another older connector, handles digital and analog connections.
Black Box Explains... Matrix video switches.
Matrix switches enable computers to mix and match the output of multiple PCs on multiple video monitors.
For instance, if your operation has four PCs and you want to display the... more/see it nowvideo on one monitor to the other three monitors, a matrix video switch is what you need to handle the job. Use matrix switches for:
• Trade showsSet up a wall of video to wow the senses of attendees.
• Transportation schedulesProvide real-time updates of flights or deliveries on multiple screens.
• Training demonstrationsControl each screens video to focus everyones attention on whats important. collapse
Black Box Explains...KVM tray technology.
KVM tray technology.
What we do that others don’t.
From the solid construction of our KVM trays, to unique features like LEDs on the ?front panel and integrated KVM switching, Black Box’s... more/see it nowKVM trays are miles ahead of the competition.
Nothing reduces clutter in a server room like KVM trays that are 1- or 2U high, and ?mount in a cabinet or rack. Here are some of the features that set our KVM trays apart.
TFT LCD support.
This type of monitor uses thin-film transistor (TFT) technology to improve image quality, resulting in higher resolutions, better image contrast, and addressability. All our KVM trays support TFT LCD panel monitors.
The screens on our KVM trays are viewable from nearly any angle. Because of the size of our screens, from 15" to 19", viewing angles vary from 140° x 120° all the way up to 160° x 160°, so you don’t always have to be standing directly in front of the monitor to see what’s happening on it.
Our ServTray Complete family of KVM trays (KVT417A-R2, etc.) has adjustable length instead of a variety of rear bracket sites. This universal rail rear bracket size fits racks with depths of 23.7" (60.2 cm) to 45.3" (115 cm). This simplifies ordering for you!
Dual rail technology.
This KVM tray technology enables the monitor drawer and the keyboard/mouse drawer to move independently of each other. It makes it easy to leave the monitor visible even when a server cabinet is closed and the keyboard/mouse drawer is fully retracted. Black Box has added switching controls to the monitor bezel that can be used to control an attached switch without pulling open the keyboard/mouse drawer for even more space-saving benefits.
Additionally, the dual rails provide a great monitoring environment without disturbing your cooling system.
You asked for it.
Our latest KVM trays, the ServView V KVM Drawer and ServView V KVM Drawer with Widescreen (KVT517A, etc.) were designed based on feedback we have received from some of our customers.
On the front panel of the tray, there is an LED panel, which helps you locate the ?drawer when it’s closed in a darkened data center. The tray only takes up 1U of rack space, and it features the dual rail technology described earlier.
We added front-panel controls for switching, so if you choose a model with an embedded KVM switch, you can use the buttons on the monitor bezel without pulling out the keyboard. Additionally, the top of the keyboard tray features a hideaway connection for USB wireless devices, such as RF- or Bluetooth® supported keyboards and mice. You can wirelessly access your attached targets, even without opening the cabinet door!
Another feature is the front-panel USB port, which provides crash cart access. If your keyboard or GlidePoint® mouse quit on you, simply use this port to attach a passthrough pointing device.
Finally, the widescreen version supports 1920 x 1080 resolutions and DVI connections — two firsts in the data center. collapse
Black Box Explains...On-screen menus.
When the ServSwitch™ brand of KVM switches was first introduced, there were only two ways to switch: from front-panel push buttons or by sending command sequences from the keyboard. While... more/see it nowthis was more convenient than having a separate keyboard, monitor, and mouse for each CPU, the operator still had to remember key combinations and which server was connected to which port—leading to many cryptic, scribbled notes attached to the switch and to the workstation.
But with the advent of on-screen menus, an operator can use easy-to-read, pop-up menus to identify and select CPUs. It’s even possible to give each CPU a name that makes sense to you—names like “MIS Server,” “Accounting Server,” and so on.
Black Box Explains...The 13W3 connector.
The 13W3 connector, also called a 13C3 or DB13W3 connector, is an unusual connector that combines a 10-pin D-shell with three analog video conductors. It supports very-high-resolution analog video signals... more/see it nowand has been used by Sun Microsystems®, SGI, NeXt, Intergraph, and other manufacturers. Although 13W3 connectors from different manufacturers look the same, they may be pinned differently.
Pinning for a standard Sun® 13W3 connector:
2: Vertical Sync*
3: Sense 2
4: Sense Ground
5: Composite Sync
6: Horizontal Sync*
8: Sense 1
9: Sense 0
10: Composite Ground
* Considered obsolete; may not be connected. collapse
Black Box Explains...UTP cable and color drift.
UTP cable is often used with video or KVM extenders to extend the reach of a video signal. It’s popular for this application because it’s lightweight, easy to handle, and... more/see it nowinexpensive. But when you transmit video over long stretches of twisted-pair cable, you sometimes run into a phenomenon called color drift or color split.
Color drift shows up as that annoying colored shadow you occasionally see around objects on a video screen. It sometimes happens with UTP cable because the pairs of wire in the cable are twisted at slightly different rates to reduce crosstalk between pairs. Because of these differences between wire pairs, video signals for different colors often travel different distances before they reach the remote receiver. When one color signal arrives behind the others because its wire is longer, you get that red, green, or blue shadow around the objects on your video screen.
UTP cable varies widely by manufacturer, so before installing video extenders, it’s difficult to determine whether or not you’re going to have a color drift problem. You’re more likely to experience color drift with higher grades (CAT5e or CAT6) of cable, on longer cable runs, and on high-resolution screens.
If you experience color drift, there are several possible solutions. You can use a shorter length of cable, switch from CAT5e or CAT6 cable to CAT5 cable, use a lower screen resolution, or use a video skew compensator.
A video skew compensator removes color drift by delaying some color signals to compensate for differences in wire pairs. collapse
Black Box Explains... ServSwitch Multi and audio cable.
Get more out of your ServSwitch Multi. Add audio cable, a set of speakers, and a microphone to each CPU. Audio cable turns your ServSwitch Multi into the ideal system... more/see it nowfor education, training, retail, medical, and multimedia office environments.
Audio cable isnt just for the ServSwitch Multi either. You can also use it with servers that give off audible alarms.
So even if you dont have audio equipment now—plan ahead. When youre ready to add audio equipment, just plug in our audio cable. collapse
Black Box Explains…Wizard.NET
One software solution to rule them all.
Wizard.NET is a professional enterprise management suite that delivers total IP device control, management, and connectivity. Black Box KVM over IP (KVMoIP) devices provide... more/see it nowthe ability to control large numbers of host computers from remote locations. When controlling larger groups of dispersed computers using numerous KVMoIP devices, the major challenge becomes one of management—retaining active control over a complex mix of devices, host computers, and registered users. Wizard.NET was developed as a common interface to help you remotely manage any number of KVMoIP devices together with all of their connected host computers and the access rights of the users.
Wizard.NET is delivered as a software solution only, and operates as a server application running on a system that can be completely separate from any of the KVMoIP devices?—?it merely requires an IP network or Internet connection. Wizard.NET uses an intuitive HTML user interface, which means that registered users can access and control it remotely using a standard Web browser. Like all Wizard KVMoIP products, Wizard.NET employs high specification security techniques to ensure that only authorized users may gain access.
Wizard.NET has two main modules, the manager and the connector. The manager module is accessible only to managers and administrators. It is where the details about all connected devices, hosts, and users are configured and stored. The connector module can be used by registered users to enable quick access to all of the targets for which they have access rights. Targets may be devices, hosts, or device groups as appropriate.
To ensure maximum security, Wizard.NET does not retain any passwords within its database for the devices that it controls. Instead, a valid password is used once only to gain access to each device during the “acquire” stage, when Wizard.NET establishes a Secure Ticket with the device. In all subsequent accesses to each device, the relevant secure ticket is used to gain access. collapse
Black Box Explains... Using fiber optics for KVM extension.
If you‘re sending KVM signals between buildings for an extended distance, in areas supplied by different power sources, in an electrically noisy environment, or where data security is a big... more/see it nowconcern, you need to use a fiber optic-based KVM extender.
Optical fiber is an ideal transmission medium not only for backbone and horizontal connection, but also for workstation-to-backracked CPU or server links. It works very well in applications where you need to transfer large, bandwidth-consuming data files over long distances, and where you require immunity from electrical interference or data theft.
The choice for extraordinary reach.
Fiber doesn’t have the 100-meter (328-ft.) distance limitation that UTP copper without a booster does. Fiber distances can range from 300 meters (984.2 ft.) to 70 kilometers (24.8 mi.), depending on the cable, wavelength, and network. With fiber-based KVM extenders, the transmitter converts conventional data signals into a modulated light beam, then transports the beam via the fiber to a receiver, which converts the light back into electrical signals.
Many newer fiber-based KVM extenders support both analog and digital transmission. Often, they work by digitizing video output from a local CPU, then sending it across fiber link to a remote unit, which converts it back to the original analog signal. In many cases, one fiber of the fiber pair transmits monitor video serially and the second fiber sends remote mouse and keyboard information back to the local CPU.
The choice for ensuring signal integrity.
Because fiber is made of glass, which is an insulator, no electric current can flow through. It’s immune to electromagnetic interference and radio-frequency interference (EMI/RFI), crosstalk, impedance problems, and more. This is why fiber-based KVM extenders are beneficial to users in process control, engineering, utility, and factory automation applications. The users need to keep critical information safe and secure off the factory floor but be able to access that data from workstations and control consoles within the harsh environments. Plus, fiber is also less susceptible to temperature fluctuations than copper is, and it can be submerged ?in water.
The choice for greater signal fidelity.
Fiber-based KVM extenders can carry more information with greater fidelity than copper-based ones can. For this reason, they’re ideal for high-data-rate systems in which multimedia workstations are used.
Newer KVM extenders enable you to send both DVI and keyboard and mouse signals over the same fiber cable, transmitting video digitally for zero signal loss. This way, you can get HD-quality resolution even at very long distances from the source. Users in university or government R&D, broadcasting, healthcare—basically anyone who depends on detailed image rendering—can benefit from this technology.
The choice for data security.
Plus, your data is safe when using fiber to connect a workstation with a CPU or server under lock and key. It doesn’t radiate signals and is extremely difficult to tap. If the cable is tapped, it’s very easy to monitor because the cable leaks light, causing the entire system to fail. If an attempt is made to break the physical security of your fiber system, you’ll know it.
Many IT managers in military, government, finance, and healthcare choose fiber-based KVM extenders for this very reason. Plus corporations, aware of rising data privacy concerns over customer billing information and the need to protect intellectual property, use this type of extension technology in their offices, too.
Considerations for fiber-based KVM extension.
Before selecting a fiber-based KVM extender, it’s important to know the limitations of your system. You need to know where couplers, links, interconnect equipment, and other devices are going to be placed. If it’s a longer run, you have to determine whether multimode or single-mode fiber cable is needed.
The most important consideration in planning cabling for fiber-based KVM extension is the power budget specification of device connection. The receiver at the remote end has to receive the light signal at a certain level. This value, called the loss budget, tells you the amount of loss in decibels (dB) that can be present in the link between the two devices before the units fail to perform properly.
Specifically, this value takes the fiber type (multimode or single-mode) and wavelength you intend to use—and the amount of expected in-line attenuation—into consideration. This is the decrease of signal strength as it travels through the fiber cable. In the budget loss calculation, you also have to account for splices, patch panels, and connectors, where additional dBs may lost in the entire end-to-end fiber extension. If the measured loss is less than the number calculated by your loss budget, your installation is good.
Testers are available to determine if the fiber cabling supports your intended application. You can measure how much light is going to the other end of the cable. Generally, these testers give you the results in dB lost, which you then compare to the loss budget to determine your link loss margin.
Also, in some instances, particularly when using single-mode fiber to drive the signal farther, the signal may be too strong between connected devices. This causes the light signal to reflect back down the fiber cable, which can corrupt data, result in a faulty transmission, and even damage equipment. To prevent this, use fiber attenuators. They’re used with ?single-mode fiber optic devices and cable to filter the strength of the fiber optic signal from the transmitter’s LED output so it doesn’t overwhelm the receiver. Depending on the type of attenuator attached to the devices at each end of the link, you can diminish the strength of the light signal a variable amount by a certain number of decibels.
Need help calculating your budget loss? Call our FREE Tech Support. If necessary, they can even recommend a fusion splicing fiber kit, a fiber tester, or a signal attenuator for your specific requirements.
Black Box Explains...Multicasting video over a LAN: Use the right switch.
In KVM extension applications where you want to distribute HD video across a network, you need to understand how it works and what kind of networking equipment to use with... more/see it nowyour extenders.
Think of your network as a river of data with a steady current of data moving smoothly down the channel. All your network users are like tiny tributaries branching off this river, taking only as much water (bandwidth) as they need to process data. When you start to multicast video, data, and audio over the LAN, those streams suddenly become the size of the main river. Each user is then basically flooded with data and it becomes difficult or impossible to do any other tasks. This scenario of sending transmissions to every user on the network is called broadcasting, and it slows down the network to a trickle. There are network protocol methods that alleviate this problem, but it depends on the network switch you use.
Unicast vs. multicasting, and why a typical Layer 2 switch isn’t sufficient.
Unicasting is sending data from one network device to another (point to point); in a typical unicast network, Layer 2 switches easily support these types of communications. But multicasting is transmitting data from one network device to multiple users. When multicasting with Layer 2 switches, all attached devices receive the packets, whether they want them or not. Because a multicast header does NOT have a destination IP address, an average network switch (a Layer 2 switch without supported capabilities) will not know what to do with it. So the switch sends the packet out to every network port on all attached devices. When the client or network interface card (NIC) receives the packet, it analyzes it and discards it if not wanted.
The solution: a Layer 3 switch with IGMPv2 or IGMPv3 and packet forwarding.
Multicasting with Layer 3 switches is much more efficient than with Layer 2 switches because it identifies the multicast packet and sends it only to the intended receivers. A Layer 2 switch sends the multicast packets to every device and, If there are many sources, the network will slow down because of all the traffic. And, without IGMPv2 or IGMPv3 snooping support, the switch can handle only a few devices sending multicasting packets.
Layer 3 switches with IGMP support, however, “know” who wants to receive the multicast packet and who doesn’t. When a receiving device wants to tap into a multicasting stream, it responds to the multicast broadcast with an IGMP report, the equivalent of saying, “I want to connect to this stream.” The report is only sent in the first cycle, initializing the connection between the stream and receiving device. If the device was previously connected to the stream, it sends a grafting request for removing the temporary block on the unicast routing table. The switch can then send the multicast packets to newly connected members of the multicast group.
Then, when a device no longer wants to receive the multicast packets, it sends a pruning request to the IGMP-supported switch, which temporarily removes the device from the multicast group and stream.
Therefore, for multicasting, use routers or Layer 3 switches that support the IGMP protocol. Without this support, your network devices will be receiving so many multicasting packets, they will not be able to communicate with other devices using different protocols, such as FTP. Plus, a feature-rich, IGMP-supported Layer 3 switch gives you the bandwidth control needed to send video from multiple sources over a LAN.