Black Box Explains...Types of KVM switches.
Black Box has the keyboard/video switches you need to share one CPU between several workstations or to control several CPUs from one monitor and keyboard.
If you do a lot of... more/see it nowswitching, you need premium switches—our top-of-the-line ServSwitch™ KVM switches give you the most reliable connections for the amount of KVM equipment supported. With ServSwitch KVM switches, you can manage as many CPUs as you want from just one workstation, and you can access any server in any computer room from any workstation. Eliminating needless equipment not only saves you money, it also gives you more space and less clutter. Plus, you can switch between PCs, Sun®, and Mac® CPUs. ServSwitch KVM switches can also cut your electricity and cooling costs because by sharing monitors, you use less power and generate less heat.
If your switching demands are very minor, you may not need products as advanced as ServSwitch. Black Box offers switches to fill less demanding needs. Most of these are manual switches or basic electronic switches, which don’t have the sophisticated emulation technology used by the ServSwitch.
For PCs with PS/2® keyboards, try our Keyboard/Video Switches. They send keyboard signals, so your CPUs boot up as though they each have their own keyboard.
With the RS/6000™ KVM Switch, you can run up to six RS/6000 servers from one workstation. Our Keyboard/ Video Switch for Mac enables you to control up to two Mac CPUs from one keyboard and monitor.
With BLACK BOX® KVM Switches, you can share a workstation with two or four CPUs. They’re available in IBM® PC and Sun Workstation® configurations.
You’ll also find that our long-life manual Keyboard/Video Switches are perfect for basic switching applications. collapse
Black Box Explains...Connecting peripherals with USB.
Before Universal Serial Bus (USB), adding peripherals required skill. You had to open your computer to install a card, set DIP switches, and make IRQ settings. Now you can connect... more/see it nowdigital joysticks, scanners, speakers, cameras, or PC telephones to your computer instantly. With USB, anyone can make the connection because everything is automatic!
Because USB connections are hot-swappable, you can attach or remove peripherals without shutting down your computer. Also, USB hubs have additional ports that enable you to daisychain multiple devices together. More than 800 leading PC, peripheral, and software manufacturers support USB. collapse
Black Box Explains...Alien crosstalk.
Alien crosstalk (ANEXT) is a critical and unique measurement in 10-GbE systems. Crosstalk, used in 10/100/1000BASE-T systems, measures the mixing of signals between wire pairs within a cable. Alien Crosstalk,... more/see it nowin 10-GbE systems, is the measurement of the signal coupling between wire pairs in
different, adjacent cables.
The amount of ANEXT depends on a number of factors, including the promixity of adjacent cables and connectors, the cable length, cable twist density, and EMI. Patch panels and connecting hardware are also affected by Alien Crosstalk.
With Alien Crosstalk, the affected cable is called the disturbed or victim cable. The surrounding cables are the disturber cables.
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...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.