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...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...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…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...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.
Black Box Explains... KVM IP gateways
Just as a gate serves as an entry or exit point to a property, a gateway serves the same purpose in the networking world. It’s the device that acts as... more/see it nowa network entrance or go-between for two or more networks.
There are different types of gateways, depending on the network.
An application gateway converts data or commands from one format to another. A VoIP gateway converts analog voice calls into VoIP packets. An IP gateway is like a media gateway, translating data from one telecommunications device to another.
Gateways often include other features and devices, such as protocol converters, routers, firewalls, encryption, voice compression, etc. Although a gateway is an essential feature of most routers, other devices, such as a PC or server, can also function as a gateway.
A KVMoIP switch contains an IP gateway, which is the pathway the KVM signals use to travel from the IP network to an existing non-IP KVM switch. It converts and directs the KVM signals, giving a user access to and control of an existing non-IP KVM switch over the Internet. collapse
Black Box Explains...KVMoIP access technology.
KVMoIP access technology extends keyboard, video, and mouse (KVM) signals from any computer or server over TCP/IP via a LAN, WAN, or Internet connection. Through this KVM over IP (KVMoIP)... more/see it nowconnection, remote users can access and control a number of servers simultaneously from wherever they are, inside or outside the organization, and anywhere in the world. This technology works in diverse hardware environments and is ideal for managing multilocation data centers and branch offices.
These capabilities translate into real savings for companies having to deal with the proliferation of servers in many offices, particularly for corporations and government agencies required to deliver 24/7 uptime and real-time access to mission-critical servers 365 days a year.
KVMoIP products combine the advantages of remote access software with the benefits of KVM switching technology. Like most KVM switches, KVMoIP products don’t require any software to be loaded on the host computers. They interface directly with the keyboard, monitor, and mouse connectors of the host computer or KVM switch. Circuitry within the KVMoIP device digitizes the incoming video signal and processes it into digital data that is communicated to a viewer program running on a remote client computer over a LAN/WAN or the public Internet.
By addressing network issues from a remote location, you can simply manage issues from your desk, or even save yourself the hassle of traveling to a site in the middle of the night. Use a browser-based connection, even a cell phone or PDA, to reboot or administer a roomful of servers remotely—a real convenience.
KVMoIP products that feature virtual media technology take that convenience further. They enable a remote user to effortlessly move files from a mass storage device—a USB flash drive or CD-ROM drive, for instance—from your location to the computer on which you’re working. Cost savings are realized through reduced downtime and less travel. Plus, in some cases, there‘s no to need replace existing KVM switches with proprietary ones to get a KVMoIP server-control solution.
The Black Box difference
Black Box® ServSwitch™ KVMoIP solutions go further than many other KVMoIP products on the market. They not only enable you to access remote servers, but they do this at the BIOS level—important when you go need to troubleshoot from off-site and don’t want to a dispatch
a technician. Install or recover software applications and install OS patches from your location anywhere in the world. Plus, this BIOS-level control is possible regardless of the server’s brand or model and even works if the operating system is down.
The ServReach™ system is also designed for IT managers seeking global centralized KVM management in a world of mushrooming servers and complexity. This global platform works by consolidating all server access and devices via locally connected KVMoIP devices. All this hardware is then united under a single management appliance or software “umbrella” providing global, yet fully secure, out-of-band control.
The ServReach system works seamlessly with more than 500 variations of analog KVM switches from a multitude of vendors and manufacturers. Because it’s vendor independent, you don’t need to replace your data center’s entire KVM infrastructure. ServReach simply
grafts global centralized KVM management onto the existing server room/data center, aligning with third-party KVM switches already in place. This is done with the ServReach KVMGate (KVIP1000A), an IP gateway device designed to connect to each of the legacy KVM devices to provide global centralized KVM management for a fraction of the cost of competitive systems, ensuring a faster and greater ROI.
If you’re planning on opening or acquiring a new data center or a large number of new servers, the ServReach KVManager (KVMGR) is the answer. It can provide any-by-any access via the ServReach KVMCube (KVIP1001A), a compact, rackmountable, digital matrix IP device that gives fully secure, non-blocking access for any of the users to any of the servers simultaneously.
In addition, the servers controlled by legacy KVM switches via KVMGate can still be managed by the ServReach KVManager at
the same time as the new servers controlled through a gateway. With all the servers under the same KVManager umbrella, data centers can now easily acquire new servers and devices without having to worry about how to incorporate the new infrastructure with the old.
For more information on Black Box KVMoIP solutions, visit blackbox.com/go/ServReach. Find out more by watching a KVMoIP demo and accessing related white papers. collapse