Black Box Explains...Giga, Giga2, and Giga Plus—what you need to know.
Our Giga, Giga2, and Giga Plus and systems feature jacks, wallplates, surface-mount boxes, and other accessories. Components of each system are designed to work together. And they all work with... more/see it nowour GigaTrue® CAT6 and GigaBase® CAT5e cable. Here are the differences between the systems so you can make the right decision when choosing hardware.
Giga products are our original line of jacks, wallplates, etc.
Giga products, such as jacks and wallplates, are designed to work with Giga products.
To meet the needs of existing Giga systems, we continue to carry Giga products.
Giga2 products are a newer line. They offer the same quality but are priced economically.
Giga2 products, such as jacks and wallplates, are designed to work with Giga2 products.
Giga Plus is our newest line and is entirely made in the U.S. So if you need to buy American-made products, choose this line.
Giga Plus products are designed to work with Giga2 products.
Black Box Explains...PC, UPC, and APC fiber connectors.
Fiber optic cables have different types of mechanical connections. The type of connection determines the quality of the fiber optic lightwave transmission. The different types well discuss here are the... more/see it nowflat-surface, Physical Contact (PC), Ultra Physical Contact (UPC), and Angled Physical Contact (APC).
The original fiber connector is a flat-surface connection, or a flat connector. When mated, an air gap naturally forms between the two surfaces from small imperfections in the flat surfaces. The back reflection in flat connectors is about -14 dB or roughly 4%.
As technology progresses, connections improve. The most common connection now is the PC connector. Physical Contact connectors are just thatthe end faces and fibers of two cables actually touch each other when mated.
In the PC connector, the two fibers meet, as they do with the flat connector, but the end faces are polished to be slightly curved or spherical. This eliminates the air gap and forces the fibers into contact. The back reflection is about -40 dB. This connector is used in most applications.
An improvement to the PC is the UPC connector. The end faces are given an extended polishing for a better surface finish. The back reflection is reduced even more to about -55 dB. These connectors are often used in digital, CATV, and telephony systems.
The latest technology is the APC connector. The end faces are still curved but are angled at an industry-standard eight degrees. This maintains a tight connection, and it reduces back reflection to about -70 dB. These connectors are preferred for CATV and analog systems.
PC and UPC connectors have reliable, low insertion losses. But their back reflection depends on the surface finish of the fiber. The finer the fiber grain structure, the lower the back reflection. And when PC and UPC connectors are continually mated and remated, back reflection degrades at a rate of about 4 to 6 dB every 100 matings for a PC connector. APC connector back reflection does not degrade with repeated matings. collapse
Cold aisle containment.
Cold aisle containment (CAC) is a cooling method that increases cooling efficiency and reduces energy costs in data centers.
This cooling method relies on the fact that most network equipment... more/see it nowand servers are designed to cool themselves by drawing air in through the front and exhausting it out the rear. To implement cold aisle containment, rows of cabinets or racks are arranged facing each other to form aisles, and cool air is routed between the rows. Equipment takes the cool air in at the front of the cabinet and exhausts it out the back into the room.
To keep cool air from mixing with warm air, row ends are closed off with an air-flow barrier. This barrier can range from makeshift arrangements of plastic strips to doors made expressly for this purpose.
Because cold aisle containment concentrates cool air at the front of equipment where it’s most needed, it’s an exceptionally effective cooling method. Cold aisle containment significantly reduces energy costs, lowering power bills as well as reducing data centers’ carbon footprints.
Black Box Explains...USB 2.0 and USB OTG.
The Universal Serial Bus (USB) hardware (plug-and-play) standard makes connecting peripherals to your computer easy.
USB 1.1, introduced in 1995, is the original USB standard. It has two data rates:... more/see it now12 Mbps for devices such as disk drives that need high-speed throughput and 1.5 Mbps for devices such as joysticks that need much lower bandwidth.
In 2002, a newer specification, USB 2.0, or Hi-Speed USB 2.0, gained wide acceptance in the industry. This version is both forward- and backward-compatible with USB 1.1. It increases the speed of the peripheral to PC connection from 12 Mbps to 480 Mbps, or 40 times faster than USB 1.1!
This increase in bandwidth enhances the use of external peripherals that require high throughput, such as CD/DVD burners, scanners, digital cameras, video equipment, and more. USB 2.0 supports demanding applications, such as Web publishing, in which multiple high-speed devices run simultaneously. USB 2.0 also supports Windows® XP through a Windows update.
An even newer USB standard, USB On-The-Go (OTG), is also in development. USB OTG enables devices other than a PC to act as a host. It enables portable equipment—such as PDAs, cell phones, digital cameras, and digital music players—to connect to each other without the need for a PC host.
USB 2.0 specifies three types of connectors: the A connector, the B connector, and the Mini B connector. A fourth type of connector, the Mini A (used for smaller peripherals such as mobile phones), was developed as part of the USB OTG specification. 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... Crosstalk.
One of the most important cable measurements is Near-End Crosstalk (NEXT). Its signal interference from one pair that adversely affects another pair on the same end.
Not only can crosstalk... more/see it nowoccur between adjacent wire pairs (pair-to-pair NEXT), but all other pairs in a UTP cable can also contribute their own levels of both near-end and far-end crosstalk, multiplying the adverse effects of this interference onto a transmitting or receiving wire pair.
Because such compounded levels of interference can prove crippling in high-speed networks, some cable manufacturers have begun listing Power Sum NEXT (PS-NEXT), FEXT, ELFEXT, and PS-ELFEXT ratings for their CAT5e and CAT6 cables. Here are explanations of the different types of measurements:
NEXT measures an unwanted signal transmitted from one pair to another on the near end.
PS-NEXT (Power Sum crosstalk) is a more rigorous crosstalk measurement that includes the total sum of all interference that can possibly occur between one pair and all the adjacent pairs in the same cable sheath. It measures the unwanted signals from multiple pairs at the near end onto another pair at the near end.
FEXT (Far-End crosstalk) measures an unwanted signal from a pair transmitting on the near end onto a pair at the far end. This measurement takes full-duplex operation into account where signals are generated simultaneously on both ends.
ELFEXT (Equal-Level Far-End Crosstalk) measures the FEXT in relation to the received signal level measured on that same pair. It basically measures interference without the effects of attenuationthe equal level.
PS-ELFEXT (Power Sum Equal-Level Far-End Crosstalk), an increasingly common measurement, measures the total sum of all intereference from pairs on the far end to a pair on the near end without the effects of attenuation. collapse
SHDSL, VDSL, VDSL2, ADSL, and SDSL.
xDSL, a term that encompasses the broad range of digital subscriber line (DSL) services, offers a low-cost, high-speed data transport option for both individuals and businesses, particularly in areas without... more/see it nowaccess to cable Internet.
xDSL provides data transmission over copper lines, using the local loop, the existing outside-plant telephone cable network that runs right to your home or office. DSL technology is relatively cheap and reliable.
SHDSL can be used effectively in enterprise LAN applications. When interconnecting sites on a corporate campus, buildings and network devices often lie beyond the reach of a standard Ethernet segment. Now you can use existing copper network infrastructure to connect remote LANS across longer distances and at higher speeds than previously thought possible.
There are various forms of DSL technologies, all of which face distance issues. The quality of the signals goes down with increasing distance. The most common will be examined here, including SHDSL, ADSL, and SDSL.
SHDSL (also known as G.SHDSL) (Single-Pair, High-Speed Digital Subscriber Line) transmits data at much higher speeds than older versions of DSL. It enables faster transmission and connections to the Internet over regular copper telephone lines than traditional voice modems can provide. Support of symmetrical data rates makes SHDSL a popular choice for businesses for PBXs, private networks, web hosting, and other services.
Ratified as a standard in 2001, SHDSL combines ADSL and SDSL features for communications over two or four (multiplexed) copper wires. SHDSL provides symmetrical upstream and downstream transmission with rates ranging from 192 kbps to 2.3 Mbps. As a departure from older DSL services designed to provide higher downstream speeds, SHDSL specified higher upstream rates, too. Higher transmission rates of 384 kbps to 4.6 Mbps can be achieved using two to four copper pairs. The distance varies according to the loop rate and noise conditions.
For higher-bandwidth symmetric links, newer G.SHDSL devices for 4-wire applications support 10-Mbps rates at distances up to 1.3 miles (2 km). Equipment for 2-wire deployments can transmit up to 5.7 Mbps at the same distance.
SHDSL (G.SHDSL) is the first DSL standard to be developed from the ground up and to be approved by the International Telecommunication Union (ITU) as a standard for symmetrical digital subscriber lines. It incorporates features of other DSL technologies, such as ADSL and SDS, and is specified in the ITU recommendation G.991.2.
Also approved in 2001, VDSL (Very High Bitrate DSL) as a DSL service allows for downstream/upstream rates up to 52 Mbps/16 Mbps. Extenders for local networks boast 100-Mbps/60-Mbps speeds when communicating at distances up to 500 feet (152.4 m) over a single voice-grade twisted pair. As a broadband solution, VDSL enables the simultaneous transmission of voice, data, and video, including HDTV, video on demand, and high-quality videoconferencing. Depending on the application, you can set VDSL to run symmetrically or asymmetrically.
VDSL2 (Very High Bitrate DSL 2), standardized in 2006, provides a higher bandwidth (up to 30 MHz) and higher symmetrical speeds than VDSL, enabling its use for Triple Play services (data, video, voice) at longer distances. While VDSL2 supports upstream/downstream rates similar to VDSL, at longer distances, the speeds don’t fall off as much as those transmitted with ordinary VDSL equipment.
ADSL (Asymmetric DSL) provides transmission speeds ranging from downstream/upstream rates of 9 Mbps/640 kbps over a relatively short distance to 1.544 Mbps/16 kbps as far away as 18,000 feet. The former speeds are more suited to a business, the latter more to the computing needs of a residential customer.
More bandwidth is usually required for downstream transmissions, such as receiving data from a host computer or downloading multimedia files. ADSLs asymmetrical nature provides more than sufficient bandwidth for these applications.
The lopsided nature of ADSL is what makes it most likely to be used for high-speed Internet access. And the various speed/distance options available within this range are one more point in ADSLs favor. Like most DSL services standardized by ANSI as T1.413, ADSL enables you to lease and pay for only the bandwidth you need.
SDSL (Symmetric DSL) represents the two-wire version of HDSL—which is actually symmetric DSL, albeit a four-wire version. SDSL is also known within ANSI as HDSL2.
Essentially offering the same capabilities as HDSL, SDSL offers T1 rates (1.544 Mbps) at ranges up to 10,000 feet and is primarily designed for business applications.
Black Box Explains...Media converters.
Media converters interconnect different cable types such as twisted pair, fiber, and coax within an existing network. They are often used to connect newer Ethernet equipment to legacy cabling.... more/see it nowThey can also be used in pairs to insert a fiber segment into copper networks to increase cabling distances and enhance immunity to electromagnetic interference (EMI).
Traditional media converters are purely Layer 1 devices that only convert electrical signals and physical media. They don’t do anything to the data coming through the link so they’re totally transparent to data. These converters have two ports—one port for each media type. Layer 1 media converters only operate at one speed and cannot, for instance, support both 10-Mbps and 100-Mbps Ethernet.
Some media converters are more advanced Layer 2 Ethernet devices that, like traditional media converters, provide Layer 1 electrical and physical conversion. But, unlike traditional media converters, they also provide Layer 2 services—in other words, they’re really switches. This kind of media converter often has more than two ports, enabling you to, for instance, extend two or more copper links across a single fiber link. They also often feature autosensing ports on the copper side, making them useful for linking segments operating at different speeds.
Media converters are available in standalone models that convert between two different media types and in chassis-based models that connect many different media types in a single housing.
Rent an apartment
Standalone converters convert between two media. But, like a small apartment, they can be outgrown. Consider your current and future applications before selecting a media converter. Standalone converters are available in many configurations, including 10BASE-T to multimode or single-mode fiber, 10BASE-T to Thin coax (ThinNet), 10BASE-T to thick coax (standard Ethernet), CDDI to FDDI, and Thin coax to fiber. 100BASE-T and 100BASE-FX models that connect UTP to single- or multimode fiber are also available. With the development of Gigabit Ethernet (1000 Mbps), media converters have been created to make the transition to high-speed networks easier.
...or buy a house.
Chassis-based or modular media converters are normally rackmountable and have slots that house media converter modules. Like a well-planned house, the chassis gives you room to grow. These are used when many Ethernet segments of different media types need to be connected in a central location. Modules are available for the same conversions performed by the standalone converters, and 10BASE-T, 100BASE-TX, 100BASE-FX, and Gigabit modules may also be mixed. collapse
Black Box Explains...Media converters that are really switches.
A media converter is a device that converts from one media type to another, for instance, from twisted pair to fiber to take advantage of fiber’s greater range. A traditional... more/see it nowmedia converter is a two-port Layer 1 device that performs a simple conversion of only the physical interface. It’s transparent to data and doesn't “see” or manipulate data in any way.
An Ethernet switch can also convert one media type to another, but it also creates a separate collision domain for each switch port, so that each packet is routed only to the destination device, rather than around to multiple devices on a network segment. Because switches are “smarter” than traditional media converters, they enable additional features such as multiple ports and copper ports that autosense for speed and duplex.
Switches are beginning to replace traditional 2-port media converters, leading to some fuzziness in terminology. Small 4- or 6-port Ethernet switches are very commonly called media converters. In fact, anytime you see a “Layer 2” media converter or a media converter with more than two ports, it’s really a small Ethernet switch.
Black Box Explains...Breakout-style cables.
With breakout- or fanout-style cables, the fibers are packaged individually. A breakout cable is basically several simplex cables bundled together in one jacket. Breakout cables are suitable for riser and... more/see it nowplenum applications, and conduit runs.
This differs from distribution-style cables where several tight-buffered fibers are bundled under the same jacket.
This design of the breakout cable adds strength to the cable, although that makes it larger and more expensive than distribution-style cables.
Because each fiber is individually reinforced, you can divide the cable into individual fiber lines. This enables quick connector termination, and eliminates the need for patch panels.
Breakout cable can also be more economical because it requires much less labor to terminate.
You may want to choose a cable that has more fibers than you actually need in case of breakage during termination or for future expansion. collapse