Loading


Content Type (x) > Black Box Explains (x)

Results 131-140 of 208 << < 11 12 13 14 15 > >> 

Black Box Explains...Remote power control.

Simply put, remote power control is the ability to reset or reboot PC, LAN, telecom, and other computer equipment without being at the equipment’s location.

Who needs remote power control?... more/see it nowAny organization with a network that reaches remote sites. This can include branch offices, unmanned information kiosks, remote monitoring stations, alarm and control systems, and even HVAC systems.

When equipment locks up at remote sites, it is usually up to the system manager at headquarters to reset it. Often, there aren’t any technically trained personnel at the remote site who can perform maintenance and resets on equipment. So, in order to save traveling time and minimize downtime, remote power control enables the system manager to take care of things at the office without ever leaving home!

Remote power control can be done with modems or existing or special phone lines. The ideal system uses “out-of-band management,“ an alternate path over an ordinary dialup line that doesn’t interfere with network equipment.

An effective remote power control system incorporates the following:
• An existing phone line, such as a line being used for a fax, modem, or phone.
• Transparent operation. The system shouldn’t interfere with or be affected by normal calls.
• Security features. The system should prevent unauthorized access to network equipment.
• Flexibility. System managers should be able to dial in from anywhere and control mulitple devices with one call.
• Have power control devices that meet UL® and FCC requirements. collapse


Black Box Explains...Power over Ethernet (PoE).

What is PoE?
The seemingly universal network connection, twisted-pair Ethernet cable, has another role to play, providing electrical power to low-wattage electrical devices. Power over Ethernet (PoE) was ratified by the... more/see it nowInstitute of Electrical and Electronic Engineers (IEEE) in June 2000 as the 802.3af-2003 standard. It defines the specifications for low-level power delivery—roughly 13 watts at 48 VDC—over twisted-pair Ethernet cable to PoE-enabled devices such as IP telephones, wireless access points, Web cameras, and audio speakers.

Recently, the basic 802.3af standard was joined by the IEEE 802.3at PoE standard (also called PoE+ or PoE plus), ratified on September 11, 2009, which supplies up to 25 watts to larger, more power-hungry devices. 802.3at is backwards compatible with 802.3af.

How does PoE work?
The way it works is simple. Ethernet cable that meets CAT5 (or better) standards consists of four twisted pairs of cable, and PoE sends power over these pairs to PoE-enabled devices. In one method, two wire pairs are used to transmit data, and the remaining two pairs are used for power. In the other method, power and data are sent over the same pair.

When the same pair is used for both power and data, the power and data transmissions don’t interfere with each other. Because electricity and data function at opposite ends of the frequency spectrum, they can travel over the same cable. Electricity has a low frequency of 60 Hz or less, and data transmissions have frequencies that can range from 10 million to 100 million Hz.

Basic structure.
There are two types of devices involved in PoE configurations: Power Sourcing Equipment (PSE) and Powered Devices (PD).

PSEs, which include end-span and mid-span devices, provide power to PDs over the Ethernet cable. An end-span device is often a PoE-enabled network switch that’s designed to supply power directly to the cable from each port. The setup would look something like this:

End-span device → Ethernet with power

A mid-span device is inserted between a non-PoE device and the network, and it supplies power from that juncture. Here is a rough schematic of that setup:

Non-PoE switch → Ethernet without PoE → Mid-span device → Ethernet with power

Power injectors, a third type of PSE, supply power to a specific point on the network while the other network segments remain without power.

PDs are pieces of equipment like surveillance cameras, sensors, wireless access points, and any other devices that operate on PoE.

PoE applications and benefits.
• Use one set of twisted-pair wires for both data and low-wattage appliances.
• In addition to the applications noted above, PoE also works well for video surveillance, building management, retail video kiosks, smart signs, vending machines, and retail point-of-information systems.
• Save money by eliminating the need to run electrical wiring.
• Easily move an appliance with minimal disruption.
• If your LAN is protected from power failure by a UPS, the PoE devices connected to your LAN are also protected from power failure.
collapse


Black Box Explains...How fiber is insulated for use in harsh environments.

Fiber optic cable not only gives you immunity to interference and greater signal security, but it’s also constructed to insulate the fiber’s core from the stress associated with use in... more/see it nowharsh environments.

The core is a very delicate channel that’s used to transport data signals from an optical transmitter to an optical receiver. To help reinforce the core, absorb shock, and provide extra protection against cable bends, fiber cable contains a coating of acrylate plastic.

In an environment free from the stress of external forces such as temperature, bends, and splices, fiber optic cable can transmit light pulses with minimal attenuation. And although there will always be some attenuation from external forces and other conditions, there are two methods of cable construction to help isolate the core: loose-tube and tight-buffer construction.

In a loose-tube construction, the fiber core literally floats within a plastic gel-filled sleeve. Surrounded by this protective layer, the core is insulated from temperature extremes, as well as from damaging external forces such as cutting and crushing.

In a tight-core construction, the plastic extrusion method is used to apply a protective coating directly over the fiber coating. This helps the cable withstand even greater crushing forces. But while the tight-buffer design offers greater protection from core breakage, it’s more susceptible to stress from temperature variations. Conversely, while it’s more flexible than loose-tube cable, the tight-buffer design offers less protection from sharp bends or twists. collapse


Black Box Explains...DIN rail.

DIN rail is an industry-standard metal rail, usually installed inside an electrical enclosure, which serves as a mount for small electrical devices specially designed for use with DIN rails. These... more/see it nowdevices snap right onto the rails, sometimes requiring a set screw, and are then wired together.

Many different devices are available for mounting on DIN rails: terminal blocks, interface converters, media converter switches, repeaters, surge protectors, PLCs, fuses, or power supplies, just to name a few.

DIN rails are a space-saving way to accommodate components. And because DIN rail devices are so easy to install, replace, maintain, and inspect, this is an exceptionally convenient system that has become very popular in recent years.

A standard DIN rail is 35 mm wide with raised-lip edges, its dimensions outlined by the Deutsche Institut für Normung, a German standardization body. Rails are generally available in aluminum or steel and may be cut for installation. Depending on the requirements of the mounted components, the rail may need to be grounded. collapse


Black Box Explains...Layer 2, 3, and 4 switches.



...more/see it now
OSI Layer Physical
Component
7-Application Applicaton Software

LAN-Compatible Software
E-Mail, Diagnostics, Word Processing, Database


Network Applications
6-Presentation Data-
Conversion Utilities
Vendor-Specific Network Shells and Gateway™ Workstation Software
5-Session Network Operating System SPX NetBIOS DECnet™ TCP/IP AppleTalk®
4-Transport Novell® NetWare® IPX™ PC LAN LAN Mgr DECnet PC/TCP® VINES™ NFS TOPS® Apple
Share®
3-Network Control
2-Data Link Network E A TR P TR E TR E E E P E P
1-Physical E=Ethernet; TR=Token Ring; A=ARCNET®; P=PhoneNET®

With the rapid development of computer networks over the last decade, high-end switching has become one of the most important functions on a network for moving data efficiently and quickly from one place to another.


Here’s how a switch works: As data passes through the switch, it examines addressing information attached to each data packet. From this information, the switch determines the packet’s destination on the network. It then creates a virtual link to the destination and sends the packet there.


The efficiency and speed of a switch depends on its algorithms, its switching fabric, and its processor. Its complexity is determined by the layer at which the switch operates in the OSI (Open Systems Interconnection) Reference Model (see above).


OSI is a layered network design framework that establishes a standard so that devices from different vendors work together. Network addresses are based on this OSI Model and are hierarchical. The more details that are included, the more specific the address becomes and the easier it is to find.


The Layer at which the switch operates is determined by how much addressing detail the switch reads as data passes through.


Switches can also be considered low end or high end. A low-end switch operates in Layer 2 of the OSI Model and can also operate in a combination of Layers 2 and 3. High-end switches operate in Layer 3, Layer 4, or a combination of the two.


Layer 2 Switches (The Data-Link Layer)

Layer 2 switches operate using physical network addresses. Physical addresses, also known as link-layer, hardware, or MAC-layer addresses, identify individual devices. Most hardware devices are permanently assigned this number during the manufacturing process.


Switches operating at Layer 2 are very fast because they’re just sorting physical addresses, but they usually aren’t very smart—that is, they don’t look at the data packet very closely to learn anything more about where it’s headed.


Layer 3 Switches (The Network Layer)

Layer 3 switches use network or IP addresses that identify locations on the network. They read network addresses more closely than Layer 2 switches—they identify network locations as well as the physical device. A location can be a LAN workstation, a location in a computer’s memory, or even a different packet of data traveling through a network.


Switches operating at Layer 3 are smarter than Layer 2 devices and incorporate routing functions to actively calculate the best way to send a packet to its destination. But although they’re smarter, they may not be as fast if their algorithms, fabric, and processor don’t support high speeds.


Layer 4 Switches (The Transport Layer)

Layer 4 of the OSI Model coordinates communications between systems. Layer 4 switches are capable of identifying which application protocols (HTTP, SNTP, FTP, and so forth) are included with each packet, and they use this information to hand off the packet to the appropriate higher-layer software. Layer 4 switches make packet-forwarding decisions based not only on the MAC address and IP address, but also on the application to which a packet belongs.


Because Layer 4 devices enable you to establish priorities for network traffic based on application, you can assign a high priority to packets belonging to vital in-house applications such as Peoplesoft, with different forwarding rules for low-priority packets such as generic HTTP-based Internet traffic.


Layer 4 switches also provide an effective wire-speed security shield for your network because any company- or industry-specific protocols can be confined to only authorized switched ports or users. This security feature is often reinforced with traffic filtering and forwarding features.

collapse


Black Box Explains…Remote monitoring.

Beyond virus protection.
It has become almost automatic to protect your data center by backing up your servers, installing firewalls and virus protection, and keeping the protection up-to-date.

But what about... more/see it nowmore tangible threats? Do you have hot spots in your racks? If the cooling system shuts down, how will you know when temperatures climb out of control? Are you alerted to humidity changes or water leaks that threaten your equipment?

Planning for the unexpected is a critical task because there are more systems performing mission-critical functions than ever before. These systems are often deployed without the proper environmental infrastructure to support them. Equipment density is increasing constantly, which is creating more stress on ventilation and power.

The top three IT risks:
1. Environmental disruption.
The number one cause of downtime for remote locations, environmental problems go beyond fires and floods and affect as much as 30% of a company’s mission-critical infrastructure. Cooling and power are key points of exposure and increase as equipment density does.

2. Unnecessary risk.
When systems are housed in less-than-optimal settings, or are in remote and unsupervised locations, any error causes downtime. Yet, it’s not practical to have someone babysitting the servers.

3. Sabotage.
Regardless of the probability, terrorism is now something each of us must plan for. Your systems can also be brought down from within if the proper security safeguards are not in place.

What’s an environmental monitoring system?
Environmental monitoring products enable you to actively monitor the conditions in your rack, server room, data center, or anywhere else you need to protect critical assets. Conditions monitored include extreme temperatures, humidity, power spikes and surges, water leaks, smoke, and chemical materials. With proper environmental monitoring, you’re alerted to any conditions that could have an adverse effect on your mission-critical equipment. These products can also alert you to potential damage from human error, hacking, or prying fingers.

Environmental monitors consist of three main elements: a base unit, probes or sensors, and network connectivity and integration. The base units may contain one or more built-in sensors, as well as ports for hooking up external probes. Additionally, they include an Ethernet port and have software for remote configuration and graphing. This software may also work with existing network management software, such as SNMP systems.

Measurement.
An environmental monitoring appliance displays the values measured by the attached probes, e.g. temperature, humidity, airflow, status of dry contact, door, motion detector, and other sensors.

Data collecting and graphing.
Measurements are periodically stored in the internal memory or external storage media and displayed as graphs.

Alerting.
When the measured value exceeds the predefined threshold, it triggers an alert: a blinking LED on the front panel, an audible alarm, SNMP trap, e-mail, etc. The environmental monitoring appliance can also activate an external alarm system like a siren or strobe light.

Benefits of environmental monitoring:

  • Reduced downtime—When things go wrong, you’re the first to know. Minimize downtime by being alerted about conditions that cause damage to servers and other network devices.
  • Increased profits—Environmental monitoring systems are easy to implement. Also, they help you cut replacement equipment costs and redistribute your workforce more effectively.
  • Increased employee satisfaction—With built-in notification features like e-mail, SMS, and SNMP traps, a remote monitoring system enables employees to better manage their work.

  • Applications:
    Envornmental and security monitoring systems can be used for a variety of applications, including:
  • Data center monitoring
  • Computer room monitoring
  • Rackmount industrial equipment
  • Telecommunications
  • UPS/battery backup
  • Educational institutions
  • Food and beverage applications
  • Buildings/warehouses
  • Air conditioner/refrigerants/freezer monitoring
  • Greenhouses
  • collapse


    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…Terminating fiber.

    Terminating fiber cable used to be a job for experts only. But today, prepolished connectors make it possible for anyone to terminate multimode fiber—all you need is a bit of... more/see it nowpatience and the right tools. Here’s how to terminate fiber with ST connectors:

    Step 1 — Slide the connector strain-relief boot, small end first, onto the cable.

    Step 2 — Using a template, mark the jacket dimensions to be stripped (40 mm and 52 mm from the end).

    Step 3 — Remove the outer jacket from the cable end to the 40 mm mark. Cut the exposed Kevlar. Carefully remove the jacket to the 52-mm mark, exposing the remaining length of Kevlar.

    Step 4 — Fan out the Kevlar fibers and slide the crimp ring of the connector approximately 5 mm over the fibers to hold them out of the way. Mark the fiber buffer 11 mm from the end of the cable jacket. Also, mark the buffer where it meets the jacket.

    Step 5 — Bit by bit, strip off the buffering until you reach the 11-mm mark. Check the mark you made on the buffer at the jacket. If it’s moved, carefully work the buffer back into the jacket to its original position.

    Step 6 — Clean the glass fiber with an alcohol wipe. Cleave the fiber to an 8-mm length.

    Step 7 — Carefully insert the fiber into the connector until you feel it bottom out and a bow forms between the connector and the clamp. Cam the connector with the appropriate tool.

    Step 8 — Crimp the connector.

    Step 9 — Slide the crimp ring up the jacket away from the connector, releasing the Kevlar fibers. Fan the fiber so they encircle the buffer. The ends of the fibers should just touch the rear of the connector—if they’re too long, trim them now.

    Step 10 — Crimp the connector again.

    Step 11 — Slide the strain-relief boot over the rear of the connector. You might want to put a bead of 411 Loctite adhesive for extra strength on the rear of the boot where it meets the jacket.

    Although the details may vary slightly with different connectors and termination kits, the basic termination procedure is the same. collapse


    Black Box Explains...Fiber connectors.

    • The ST® connector, which uses a bayonet locking system, is the most common connector.

    • The SC connector features a molded body and a push- pull locking system.

    • The FDDI... more/see it nowconnector comes with a 2.5-mm free-floating ferrule and a fixed shroud to minimize light loss.

    • The MT-RJ connector, a small-form RJ-style connector, features a molded body and uses cleave-and-leave splicing.

    • The LC connector, a small-form factor connector, features a ceramic ferrule and looks like a mini SC connector.

    • The VF-45™connector is another small-form factor connector. It uses a unique “V-groove“ design.

    • The FC connector is a threaded body connector. Secure it by screwing the connector body to the mating threads. Used in high-vibration environments.

    • The MTO/MTP connector is a fiber connector that uses high-fiber-count ribbon cable. It’s used in high-density fiber applications.

    • The MU connector resembles the larger SC connector. It uses a simple push-pull latching connection and is well suited for high-density applications.
    collapse


    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

    Results 131-140 of 208 << < 11 12 13 14 15 > >> 
    Close

    Support

    Delivering superior technical support is our highest priority. Depending on the products or services we provide for you, please visit your appropriate support area.



     

    You have added this item to your cart.

    Print
    Black Box 1-877-877-2269 Black Box Network Services