Black Box Explains...Category wiring standards
The ABCs of standards
There are two primary organizations dedicated to developing and setting structured cabling standards. In North America, standards are issued by the Telecommunications Industry Association (TIA),... more/see it nowwhich is accredited by the American National Standards Institute (ANSI). The TIA was formed in April 1988 after a merger with the Electronics Industry Association (EIA). That’s why its standards are commonly known as ANSI/TIA/EIA, TIA/EIA, or TIA.
Globally, the organizations that issue standards are the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO). Standards are often listed as ISO/IEC. Other organizations include the Canadian Standards Association (CSA), CENELEC (European Committee for Electrotechnical Standardizations), and the Japanese Standards Association (JSA/JSI).
The committees of all these organizations work together and the performance requirements of the standards are very similar. But there is some confusion in terminology.
The TIA cabling components (cables, connecting hardware, and patch cords) are labeled with a ”category.” These components together form a permanent link or channel that is also called a ”category.” The ISO/IEC defines the link and channel requirements with a ”class” designation. But the components are called a ”category.”
Category 5 (CAT5) —ratified in 1991. It is no longer recognized for use in networking.
Category 5e (CAT5e), ISO/IEC 11801 Class D, ratified in 1999, is designed to support full-duplex, 4-pair transmission in 100-MHz applications. The CAT5e standard introduced the measurement for PS-NEXT, EL-FEXT, and PS-ELFEXT. CAT5e is no longer recognized for new installations. It is commonly used for 1-GbE installations.
Category 6 (CAT6) – Class E has a specified frequency of 250 MHz, significantly improved bandwidth capacity over CAT5e, and easily handles Gigabit Ethernet transmissions. CAT6 supports 1000BASE-T and, depending on the installation, 10GBASE-T (10-GbE).
10-GbE over CAT6 introduces Alien Crosstalk (ANEXT), the unwanted coupling of signals between adjacent pairs and cables. Because ANEXT in CAT6 10-GbE networks is so dependent on installation practices, TIA TSB-155-A and ISO/IEC 24750 qualifies 10-GbE over CAT6 over channels of 121 to 180 feet (37 to 55 meters) and requires it to be 100% tested, which is extremely time consuming. To mitigate ANEXT in CAT6, it is recommended that the cables be unbundled, that the space between cables be increased, and that non-adjacent patch panel ports be used. If CAT6 F/UTP cable is used, mitigation is not necessary and the length limits do not apply. CAT6 is not recommended for new 10-GbE installations.
Augmented Category 6 (CAT6A) –Class Ea was ratified in February 2008. This standard calls for 10-Gigabit Ethernet data transmission over a 4-pair copper cabling system up to 100 meters. CAT6A extends CAT6 electrical specifications from 250 MHz to 500 MHz. It introduces the ANEXT requirement. It also replaces the term Equal Level Far-End Crosstalk (ELFEXT) with Attenuation to Crosstalk Ratio, Far-End (ACRF) to mesh with ISO terminology. CAT6A provides improved insertion loss over CAT6. It is a good choice for noisy environments with lots of EMI. CAT6A is also well-suited for use with PoE+.
CAT6A UTP cable is significantly larger than CAT6 cable. It features larger conductors, usually 22 AWG, and is designed with more space between the pairs to minimize ANEXT. The outside diameter of CAT6A cable averages 0.29"–0.35" compared to 0.21"–0.24" for CAT6 cable. This reduces the number of cables you can fit in a conduit. At a 40% fill ratio, you can run three CAT6A cables in a 3/4" conduit vs. five CAT6 cables.
CAT6A UTP vs. F/UTP. Although shielded cable has the reputation of being bigger, bulkier, and more difficult to handle and install than unshielded cable, this is not the case with CAT6A F/UTP cable. It is actually easier to handle, requires less space to maintain proper bend radius, and uses smaller conduits, cable trays, and pathways. CAT6A UTP has a larger outside diameter than CAT6A F/UTP cable. This creates a great difference in the fill rate of cabling pathways. An increase in the outside diameter of 0.1", from 0.25" to 0.35" for example, represents a 21% increase in fill volume. In general, CAT6A F/UTP provides a minimum of 35% more fill capacity than CAT6A UTP. In addition, innovations in connector technology have made terminating CAT6A F/UTP actually easier than terminating bulkier CAT6A UTP.
Category 7 (CAT7) –Class F was published in 2002 by the ISO/IEC. It is not a TIA recognized standard and TIA plans to skip over it.
Category 7 specifies minimum performance standards for fully shielded cable (individually shielded pairs surrounded by an overall shield) transmitting data at rates up to 600 MHz. It comes with one of two connector styles: the standard RJ plug and a non-RJ-style plug and socket interface specified in IEC 61076-2-104:2.
Category 7a (CAT7a) –Class Fa (Amendment 1 and 2 to ISO/IEC 11801, 2nd Ed.) is a fully shielded cable that extends frequency from 600 MHz to 1000 MHz.
Category 8 – The TIA decided to skip Category 7 and 7A and go to Category 8. The TR-42.7 subcommittee is establishing specs for a 40-Gbps twisted-pair solution with a 2-GHz frequency. The proposed standard is for use in a two-point channel in a data center at 30 meters. It is expected to be ratified in February 2016. The TR-42.7 subcommittee is also incorporating ISO/IEC Class II cabling performance criteria into the standard. It is expected to be called TIA-568-C.2-1. The difference between Class I and Class II is that Class II allows for three different styles of connectors that are not compatible with one another or with the RJ-45 connector. Class I uses an RJ-45 connector and is backward compatible with components up to Category 6A.
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.
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.
Converters and Scalers Selector
IEEE 802.3 af
|PoE IEEE 802.3 at
|Power available at powered device
|Maximum power delivered
|Voltage range at powred source
|Voltage range at powred device
|Maximum cable resistance
Black Box Explains...What to look for in a channel solution.
Channel solution. You hear the term a lot these days to describe complete copper or fiber cabling systems. But what exactly is a channel solution and what are its benefits?... more/see it now
A channel solution is a cabling system from the data center to the desktop where every cable, jack, and patch panel is designed to work together and give you consistent end-to-end performance when compared with the EIA/TIA requirements.
A channel solution is beneficial because you have some assurance that your cabling components will perform as specified. Without that assurance, one part may not be doing its job, so your entire system may not be performing up to standard, which is a problem — especially if you rely on bandwidth-heavy links for video and voice.
What to look for.
There are a lot of channel solutions advertised on the Internet and elsewhere. So what exactly should you be looking for?
For one, make sure it’s a fully tested, guaranteed channel solution. The facts show an inferior cabling system can cause up to 70 percent of network downtime — even though it usually represents only 5 percent of an initial network investment. So don’t risk widespread failure by skimping on a system that doesn’t offer guaranteed channel performance. You need to make sure the products are engineered to meet or go beyond the key measurements for CAT5e or CAT6 performance.
And, sure, they may be designed to work together, but does the supplier absolutely guarantee how well they perform as part of a channel — end to end? Don’t just rely on what the supplier says. They may claim their products meet CAT5e or CAT6 requirements, but the proof is in the performance. Start by asking if the channel solution is independently tested and certified by a reputable third party. There are a lot of suppliers out there who don’t have the trademarked ETL approval logo, for example.
What ETL Verified means.
The ETL logo certifies that a channel solution has been found to be in compliance with recognized standards.
To ensure consistent top quality, Black Box participates in independent third-party testing by InterTek Testing Services/ETL Semko, Inc. Once a quarter, an Intertek inspector visits
Black Box and randomly selects cable and cabling products
The GigaTrue® CAT6 and GigaBase® CAT5e Solid Bulk Cable are ETL Verified at the component level to verify that they conform to the applicable industry standards.
The GigaTrue® CAT6 and GigaBase® CAT5e Channels, consisting of bulk cable, patch cable, jacks, patch panels, and wiring blocks, are tested and verified according to industry standards in a LAN environment under InterTek’s Cabling System Channel Verification Program. For the latest test results, contact our FREE Tech Support.
Black Box Explains... Pulling eyes and fiber cable.
Fiber optic cable can be damaged if pulled improperly. Broken or cracked fiber, for example, can result from pulling on the fiber core or jacket instead of the strength member.... more/see it nowAnd too much tension or stress on the jacket, as well as too tight of a bend radius, can damage the fiber core. If the cables core is harmed, the damage can be difficult to detect.
Once the cable is pulled successfully, damage can still occur during the termination phase. Field termination can be difficult and is often done incorrectly, resulting in poor transmission. One way to eliminate field termination is to pull preterminated cable. But this can damage the cable as well because the connectors can be knocked off during the pulling process. The terminated cable may also be too bulky to fit through ducts easily. To help solve all these problems, use preterminated fiber optic cable with a pulling eye. This works best for runs up to 2000 feet (609.6 m).
The pulling eye contains a connector and a flexible, multiweave mesh-fabric gripping tube. The latched connector is attached internally to the Kevlar®, which absorbs most of the pulling tension. Additionally, the pulling eyes mesh grips the jacket over a wide surface area, distributing any remaining pulling tension and renders it harmless. The end of the gripping tube features one of three different types of pulling eyes: swivel, flexible, or breakaway.
Swivel eyes enable the cable to go around bends without getting tangled. They also prevent twists in the pull from being transferred to the cable. A flexible eye follows the line of the pull around corners and bends, but its less rigid. A breakaway eye offers a swivel function but breaks if the tension is too great. We recommend using the swivel-type pulling eye.
A pulling eye enables all the fibers to be preterminated to ensure better performance. The terminated fibers are staggered inside the gripping tube to minimize the diameter of the cable. This enables the cable to be pulled through the conduit more easily. collapse
Black Box Explains...SFP, SFP+, and XFP transceivers.
SFP, SFP+, and XFP are all terms for a type of transceiver that
plugs into a special port on a switch or other network device to convert the port to... more/see it nowa copper or fiber interface. These compact transceivers replace the older, bulkier GBIC interface. Although these devices are available in copper, their most common use is to add fiber ports. Fiber options include multimode and single-mode fiber in a variety of wavelengths covering distances of up to 120 kilometers (about 75 miles), as well as WDM fiber, which uses two separate wavelengths to both send and receive data on a
single fiber strand.
SFPs support speeds up to 4.25 Gbps and are generally used for Fast Ethernet or Gigabit Ethernet applications. The expanded SFP
standard, SFP+, supports speeds of 10 Gbps or higher over fiber. XFP
is a separate standard that also supports 10-Gbps speeds. The primary difference between SFP+ and the slightly older XFP standard is that SFP+ moves the chip for clock and data recovery into a line card on the host device. This makes an SFP+ smaller than an XFP, enabling greater port density.
Because all these compact transcievers are hot-swappable, there’s no need to shut down a switch to swap out a module—it’s easy to change interfaces on the fly for upgrades and maintenance.
Another characteristic shared by this group of transcievers is that they’re OSI Layer 1 devices—they’re transparent to data and do not examine or alter data in any way. Although they’re primarily used with Ethernet, they’re also compatible with uncommon or legacy standards such as Fibre Channel, ATM, SONET, or Token Ring.
Formats for SFP, SFP+, and XFP transceivers have been standardized by multisource agreements (MSAs) between manufacturers, so
physical dimensions, connectors, and signaling are consistent and
interchangeable. Be aware though that some major manufacturers, notably Cisco, sell network devices with slots that lock out transceivers from other vendors.
Black Box Explains...IRQs, COM Ports, and Windows
Windows® 95 normally requires each serial port to have its own unique Interrupt Request Line (IRQ). However, if you use a third-party communications driver that supports IRQ sharing, you can... more/see it nowshare interrupts. Unfortunately, data throughput will not be as high as with single interrupt port configurations.
With Windows NT®, you can share interrupts across multiple ports as long as the serial ports have an Interrupt Status Port (ISP) built into the card.
The Interrupt Service Routine, a software routine that services interrupts and requests processor time, reads the ISP and is immmediately directed to the port that has an interrupt pending. Compared to the polling method used if the serial ports don’t have an ISP, this feature can determine which port generated the interrupt up to four times more efficiently—and it almost eliminates the risk of lost data. Windows NT supports the ISP by enabling the user to configure the registry to match the card’s settings. Black Box models IC102C-R3, IC058C, and IC112C-R3 all have ISPs and come with a Windows NT setup utility to simplify installation and configuration.
If your serial port doesn’t have an ISP, the Interrupt Service Routine has to poll each port separately to determine which port generated the interrupt. collapse
Black Box Explains... Industrial modem benefits.
Not all modems shuttle data in air-conditioned, climate-controlled comfort. And modems that operate in cozy environments have absolutely no business being exposed to harsh industrial conditions or to the elements.
But... more/see it nowjust because you work in a rough-and-tumble place doesnt mean you have to sacrifice the convenience of a good modem. Instead, you should opt for an industrial modem. There are many industrial modems built for various degrees of extremity.
Survivability depends on reliability.
Sure, standard modems give you access to data in remote sites or enable you to service equipment on the plant floor—and you can do all this from the convenience of your office. However, these benefits are only possible if your modem can continue to function in its environment. And since standard modems arent built for adverse conditions, theyre not going to be reliable.
No penalties for interference.
Electrical control equipment—such as motors, relays, compressors, and generators—emit electromagnetic interference (EMI) that can affect the performance and reliability of a standard telephone modem.
EMI is emitted through power lines, the RS-232 communications cable, or through the telephone line itself. The very means of data communication, cable, is often the worst enemy of the standard modems that use it.
An industrial modem, on the other hand, has filters and superior EMI immunity to protect itself and your data. If you build your electrical cabinets to UL® or CSA standards, remember that your modem must also conform to UL® standard 508.
They go to extremes.
Temperature is the biggest killer of electronic equipment in industrial environments. The heat generated by industrial equipment in sealed enclosures or where space is a premium can make the temperature as much as 50 °F higher than the surrounding environment.
So standard modems cant take the heat. But what about being outdoors in the other extreme, cold weather? Well, standard modems cant take the cold either.
If you install your equipment in remote outdoor locations, it must work on the coldest days— especially those cold days when you least want to get in the car and go to the site to repair a standard modem that froze up.
Whether theyre placed in manufacturing environments or the great outdoors, industrial modems get the data through when you need it. They go to extremes for you.
Heavy metal for all kinds of banging around.
Industrial modems are built with durable metal enclosures that protect circuitry in rough conditions and ward off signal-disrupting EMI. Plus, they feature steel-bolt flanges to anchor them. In short, industrial modems can take the physical, heavy-duty punishment thrown their way.
So where exactly can you use an industrial modem?
• Heavy industry and manufacturing
• Oil and gas fields
• Storage sites
• Utility substations
• Agricultural projects
• Military facilities
• Research installations
• Water/wastewater systems
and another thing!
If dedicated copper lines cant be run through industrial environments, or if the fiber optic option is cost-prohibitive, there are also wireless industrial modems that make line-of-sight connections. If theres a way to get the data through, industrial modems will get the job done.
Industrial modems remain in service for a very long time. But if you ever need a replacement that is hardware or software compatible, be assured that Black Box continues to support its products year after year—so you don’t spend your time re-engineering systems if you have to make a replacement. collapse
Black Box Explains…Media converters that also work as switches.
Media converters transparently convert the incoming electrical signal from one cable type and then transmit it over another type—thick coax to Thin, UTP to fiber, and so on. Traditionally, media... more/see it nowconverters were purely Layer 1 devices that only converted electrical signals and physical media and didn’t do anything to the data coming through the link.
Today’s media converters, however, are often 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 and route Ethernet packets based on MAC address. These media converters are often called media converter switches, switching media converters, or Layer 2 media converters. They enable you to have multiple connections rather than just one simple in-and-out connection. And because they’re switches, they increase network efficiency.
Media converters are often used to connect newer 100-Mbps, Gigabit Ethernet, or ATM equipment to existing networks, which are generally 10BASE-T, 100BASE-T, or a mixture of both. They can also be used in pairs to insert a fiber segment into copper networks to increase cabling distances and enhance immunity to electromagnetic interference.
Rent an apartment…
Media converters are available in standalone models that convert between two different media types and in chassis-based models that house many media converters in a a single chassis.
Standalone models convert between two media. But, like a small apartment, they can be outgrown.
Consider your current and future applications before selecting a media converter. A good way to anticipate future network requirements is to choose media converters that work as standalone devices but can be rackmounted if needed later.
…or buy a house.
Chassis-based or modular media converter systems are normally rackmountable and have slots to 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 they enable you to mix different media types such as 10BASE-T, 100BASE-TX, 100BASE-FX, ATM, and Gigabit modules. Although enterprise-level chassis-based systems generally have modules that can only be used in a chassis, many midrange systems feature modules that can be used individually or in a chassis. collapse
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.