Black Box Explains...10-GbE, CAT6A, and ANEXT.
The IEEE released the 802.3an 10GBASE-T standard in June 2006. This standard specifies 10-Gbps data transmission
over four-pair copper cabling. 10-Gigabit Ethernet (10-GbE) transmission includes up to 37 meters of... more/see it nowCAT6 cable (with installation mitigation techniques), 100 meters of Augmented Category 6 (CAT6A) UTP or F/UTP cable or 100 meters
of S/FTP CAT7/Class F cable.
CAT6A is the ANSI/TIA 10-Gigabit Ethernet (10-GbE) over copper standard. Its requirements are covered in ANSI/TIA-568-C.2 (Balanced Twisted-Pair Communications Cabling and Components Standard) published in August 2009. It defines 10-Gigabit data transmission over a 4-connector twisted-pair CAT6A copper cable for a distance of 100 meters.
Category 6A cabling is designed to support next-generation applications, including the transfer of large amounts of data at high speeds, up to 10 Gbps. CAT6A extends electrical specifications to 500 MHz from 250 MHz for CAT6 cabling. CAT6A cables are fully backward compatible with previous categories, including CAT6 and 5e. Category 6A is also designed to support bundled cable installations up to 100 meters and PoE+ low-power implementations. The standard includes the performance parameter, Alien Crosstalk (ANEXT). Because of its higher performance transmission speeds and higher MHz rating, CAT6A cable needs to be tested for external noise outside the cable, which wasn’t a concern with previous cabling categories. CAT6A UTP also has a much larger diameter than previous cables.
Alien crosstalk (ANEXT) is a critical and unique measurement in 10-GbE systems. Crosstalk, measured in 10/100/1000BASE-T systems, is the mixing of signals between wire pairs within a cable. Alien Crosstalk, in 10-GbE systems, is the measurement of the unwanted signal coupling between wire pairs in different and adjacent cables or from one balanced twisted-pair component, channel, or permanent link to another.
The amount of ANEXT depends on a number of factors, including the type of cable, cable jacket, cable length, cable twist density, proximity of adjacent cables, and connectors, and EMI. Patch panels and connecting hardware are also affected by ANEXT.
With Alien Crosstalk, the affected cable is called the victim cable. The surrounding cables are the disturber cables.
There are a number of ways to mitigate the effects of ANEXT in CAT6A runs. According to the standards, ANEXT can be improved by laying CAT6A UTP cable loosely in pathways and raceways with space between the cables. This contrasts to the tightly bundled runs of CAT6/5e cable that we are used to. The tight bundles present a worst-case scenario of six cables around one, thus the center cable would be adversely affected by ANEXT. CAT6A UTP cable needs to be tested for ANEXT. This is a complex and time-consuming process in which all possible wire-pair combinations need to be tested for ANEXT and far-end ANEXT. It can take 50 minutes to test one link in a bundle of 24 CAT 6A UTP cables.
To virtually eliminate the problem of ANEXT, you can use CAT6A F/UTP cable. The F indicates an outer foil shield encasing four unshielded twisted pairs. This cable is also a good choice when security is an issue because it doesn’t emit signals. In addition, CAT6A F/UTP cable works well in noisy environments with a lot of EMI/RFI.
Installation of CAT6A F/UTP is simpler, too, because the cable features a smaller outside diameter than CAT6A UTP. Its construction makes it easier to pull and more resilient. The cable also has a smaller diameter so you can run more cables in a conduit or pathway, and have greater patch panel port density.
For more information, see the CAT6A F/UTP vs. UTP: What You Need to Know white paper in the Resources section at blackbox.com.
Black Box Explains...NEMA 12 certification.
The National Electrical Manufacturers Association (NEMA) specifies guidelines for cabinet certifications. NEMA 12 cabinets are constructed for indoor use to provide protection against certain contaminants that might come in contact... more/see it nowwith the enclosed equipment. The NEMA 12 designation means a particular cabinet has met the guidelines, which include protection against falling dirt, circulating dust, lint, fibers, and dripping or splashing non-corrosive liquids. Protection against oil and coolant seepage is also a prerequisite for NEMA 12 certification.
Organizations with mission-critical equipment benefit from a NEMA 12 cabinet. Certain environments put equipment at a higher risk than others. For example, equipment in industrial plants is subject to varying degrees of extreme temperature. Even office buildings generate lots of dust and moisture, which is detrimental to equipment. NEMA 12 enclosures help to ensure that your operation suffers from as little downtime as possible. collapse
Black Box Explains...The 13W3 connector.
The 13W3 connector, also called a 13C3 or DB13W3 connector, is an unusual connector that combines a 10-pin D-shell with three analog video conductors. It supports very-high-resolution analog video signals... more/see it nowand has been used by Sun Microsystems®, SGI, NeXt, Intergraph, and other manufacturers. Although 13W3 connectors from different manufacturers look the same, they may be pinned differently.
Pinning for a standard Sun® 13W3 connector:
2: Vertical Sync*
3: Sense 2
4: Sense Ground
5: Composite Sync
6: Horizontal Sync*
8: Sense 1
9: Sense 0
10: Composite Ground
* Considered obsolete; may not be connected. 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.
Black Box Explains...10-Gigabit Ethernet.
10-Gigabit Ethernet, sometimes called 10-GbE or 10 GigE, is the latest improvement on the Ethernet standard, ratified in 2003 for fiber as the 802.3ae standard, in 2004 for twinax cable... more/see it now
as the 802.3ak standard, and in 2006 for UTP as the 802.3an standard.
10-Gigabit Ethernet offers ten times the speed of Gigabit Ethernet. This extraordinary throughput plus compatibility with existing Ethernet standards has resulted in 10-Gigabit Ethernet quickly becoming the new standard for high-speed network backbones, largely supplanting older technologies such as ATM over SONET. 10-Gigabit Ethernet has even made inroads in the area of storage area networks (SAN) where Fibre Channel has long been the dominant standard. This new Ethernet standard offers a fast, simple, relatively inexpensive way to incorporate super high-speed links into your network.
Because 10-Gigabit Ethernet is simply an extension of the existing Ethernet standards family, it’s a true Ethernet standard—it’s totally backwards compatible and retains full compatibility with 10-/100-/1000-Mbps Ethernet. It has no impact on existing Ethernet nodes, enabling you to seamlessly upgrade your network with straightforward upgrade paths and scalability.
10-Gigabit Ethernet is less costly to install than older high-speed standards such as ATM.
And not only is it relatively inexpensive to install, but the cost of network maintenance and management also stays low—10-Gigabit Ethernet can easily be managed by local network administrators.
10-Gigabit Ethernet is also more efficient than other high-speed standards. Because it uses the same Ethernet frames as earlier Ethernet standards, it can be integrated into your network using switches rather than routers. Packets don’t need to be fragmented, reassembled, or translated for data to get through.
Unlike earlier Ethernet standards, which operate in half- or full-duplex, 10-Gigabit Ethernet operates in full-duplex only, eliminating collisions and abandoning the CSMA/CD protocol used to negotiate half-duplex links. It maintains MAC frame compatibility with earlier Ethernet standards with 64- to 1518-byte frame lengths. The 10-Gigabit standard does not support jumbo frames, although there are proprietary methods for accommodating them.
Fiber 10-Gigabit Ethernet standards
There are two groups of physical-layer (PHY) 10-Gigabit Ethernet standards for fiber:
LAN-PHY and WAN-PHY.
LAN-PHY is the most common group of standards. It’s used for simple switch and router
connections over privately owned fiber and uses a line rate of 10.3125 Gbps with 64B/66B
The other group of 10-Gigabit Ethernet standards, WAN-PHY, is used with SONET/SDH
interfaces for wide area networking across cities, states—even internationally.
10GBASE-SR (Short-Range) is a serial short-range fiber standard that operates over two multimode fibers. It has a range of 26 to 82 meters (85 to 269 ft.) over legacy 62.5-µm 850-nm fiber and up to 300 meters (984 ft.) over 50-µm 850-nm fiber.
10GBASE-LR (Long-Range) is a serial long-range 10-Gbps Ethernet standard that operates at ranges of up to 25 kilometers (15.5 mi.) on two 1310-nm single-mode fibers.
10GBASE-ER (Extended-Range) is similar to 10GBASE-LR but supports distances up to 40 kilometers (24.9 mi.) over two 1550-nm single-mode fibers.
10GBASE-LX4 uses Coarse-Wavelength Division Multiplexing (CWDM) to achieve ranges of 300 meters (984 ft.) over two legacy 850-nm multimode fibers or up to 10 kilometers (6.2 mi.) over two 1310-nm single-mode fibers. This standard multiplexes four data streams over four different wavelengths in the range of 1300 nm. Each wavelength carries 3.125 Gbps to achieve 10-Gigabit speed.
In fiber-based Gigabit Ethernet, the 10GBASE-SR, 10GBASE-LR, and 10GBASE-ER LAN-PHY standards have WAN-PHY equivalents called 10GBASE-SW, 10GBASE-LW, and 10GBASE-EW. There is no WAN-PHY standard corresponding to 10GBASE-LX4.
WAN-PHY standards are designed to operate across high-speed systems such as SONET and SDH. These systems are often telco operated and can be used to provide high-speed data delivery worldwide. WAN-PHY 10-Gigabit Ethernet operates within SDH and SONET using an SDH/SONET frame running at 9.953 Gbps without the need to directly map Ethernet frames into SDH/SONET.
WAN-PHY is transparent to data—from the user’s perspective it looks exactly the same as LAN-PHY.
10-Gigabit Ethernet over Copper
10GBASE-CX4 is a standard that enables Ethernet to run over CX4 cable, which consists of four twinaxial copper pairs bundled into a single cable. CX4 cable is also used in high-speed InfiniBand® and Fibre Channel storage applications.
Although CX4 cable is somewhat less expensive to install than fiber optic cable, it’s limited to distances of up to 15 meters. Because this standard uses such a specialized cable at short distances, 10GBASE-CX4 is generally used only in limited data center applications such as connecting servers or switches.
10GBASE-Kx is backplane 10-Gigabit Ethernet and consists of two standards. 10GBASE-KR is a serial standard compatible with 10GBASE-SR, 10GBASE-LR, and 10GBASE-ER. 10GBASE-KX4 is compatible with 10GBASE-LX4. These standards use up to 40 inches of copper printed circuit board with two connectors in place of cable. These very specialized standards are used primarily for switches, routers, and blade servers in data center applications.
10GBASE-T is the 10-Gigabit standard that uses the familiar shielded or unshielded copper UTP cable. It operates at distances of up to 55 meters (180 ft.) over existing Category 6 cabling or up to 100 meters (328 ft.) over augmented Category 6, or “6a,” cable, which is specially designed to reduce crosstalk between UTP cables. Category 6a cable is somewhat bulkier than Category 6 cable but retains the familiar RJ-45 connectors.
To send data at these extremely high speeds across four-pair UTP cable, 10GBASE-T uses sophisticated digital signal processing to suppress crosstalk between pairs and to remove signal reflections.
10-Gigabit Ethernet Applications
> 10-Gigabit Ethernet is already being deployed in applications requiring extremely
> As a lower-cost alternative to Fibre Channel in storage area networking (SAN)
> High-speed server interconnects in server clusters.
> Aggregation of Gigabit segments into 10-Gigabit Ethernet trunk lines.
> High-speed switch-to-switch links in data centers.
> Extremely long-distance Ethernet links over public SONET infrastructure.
Although 10-Gigabit Ethernet is currently being implemented only by extremely high-volume users such as enterprise networks, universities, telecommunications carriers, and Internet service providers, it’s probably only a matter of time before it’s delivering video to your desktop. Remember that only a few years ago, a mere 100-Mbps was impressive enough to be called “Fast Ethernet.”
Black Box Explains...ISDN Basics.
ISDN stands for Integrated Services Digital Network. It’s a high-speed digital data service provided by most phone companies. With ISDN you can transmit large amounts of data, voice, and video... more/see it nowsignals up to 128 kbps over a single phone line.
The most common (and least expensive) ISDN service is Basic Rate Interface, or BRI. It’s usually used to combine voice and data circuits over one line between small-scale ISDN sites. BRI consists of two 64-kbps B channels plus a 16-kbps D channel to support system “overhead” functions, such as signaling the telecomm switching system to initiate a call.
What makes ISDN unique is that each B channel is a separate communication circuit. That means just one ISDN line can support simultaneous two-way communication for two devices, such as a computer and a telephone or a computer and a video camera for teleconferencing.
If you need to send more data than one 64-kbps B channel can handle, ISDN also supports BONDing for inverse multiplexing. This links the two B channels into a single logical circuit that can support data rates up to 128 kbps.
ISDN lines are terminated at your location with a special RJ-45 jack. There are two main interfaces. The U interface consists of two wires (one twisted pair) and is common in North America. The S/T interface consists of four unshielded wires (two twisted pairs) and is more common outside North America. Unless you already own U-compatible ISDN phones or PCs, you’ll need a terminal adapter to make the connection.
ISDN is the perfect choice when faster data rates, lower prices, and guaranteed data integrity are required. Consider it for high-volume datacomm applications such as Internet access and on-line service, telecommuting, remote-office routing, and disaster recovery. Also consider ISDN for a high-speed backup line—because you never know when you’ll need one. collapse
Black Box Explains... Smart Serial Interface
Smart Serial is the Cisco router interface. It uses a space-saving 26-pin connector that automatically detects RS-232, RS-449, RS-530, X.21, and V.35 interfaces for both DTE and DCE devices based... more/see it nowon the type of cable used.
Smart Serial connectors can be found on Smart Serial cables and on the dual-serial-port WAN interface cards used in Cisco 2600 and 1720 series routers. The cables feature a Smart Serial connector on one end and a standard cable connector (such as DB25 or V.35) on the other end. The Smart Serial connector attaches to the dual-serial-port WAN interface card.
Each port on the WAN interface card features a Smart Serial connector. Ports can be configured independently to support two different physical interfaces. For example, you can run RS-232 cable to one port and RS-449 cable to the other port using a single WAN interface card.
What if you need to replace that RS-232 cable with V.35 cable? Just plug a Smart SerialV.35 cable into the port. Because any Smart Serial connector on the WAN interface card attaches to any Smart Serial cable connector, no additional interface or adapter is necessary. Changing the configuration of your network is literally a snap! collapse
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 equipments 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 arent 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 doesnt 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 shouldnt 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...Coax connectors.
The BNC (Bayonet-Neill-Concelman) connector is the most commonly used coax connector. This large ”bayonet“ connector features a slotted outer conductor and an inner plastic dielectric, and it offers easy connection... more/see it nowand disconnection. After insertion, the plug is turned, tightening the pins in the socket. It is widely used in video and Radio Frequency (RF) applications up to 2.4 GHz. It is also common in 10BASE2 Ethernet networks, on cable interconnections, network cards, and test equipment.
The TNC connector is a threaded version of the BNC connector. It works in frequencies up to 12 GHz. It‘s commonly used in cellular telephone RF/antenna applications.
The N connector is a larger, threaded connector that was designed in the 1940s for military systems operating at less than 5 GHz. In the 1960s, improvements raised performance to 12 GHz. The connector features an internal gasket and is hand tightened. It is common on 2.4-GHz antennas.
The UHF connector looks like a coarse-threaded, big center-conductor version of the N connector. It was developed in the 1930s. It is suitable for use up to 200–300 MHz and generally offers nonconstant impedance.
The F connector is most often used in cable and satellite TV and antenna applications; and it performs well at high frequencies. The connector has a 3/8–32 coupling thread. Some F connectors are also available in a screw-on style.
The SMA (Subminiature A) connector is one of the most common RF/microwave connectors. This small, threaded connector is used on small cables that won’t be connected and disconnected often. It’s designed for use to 12.4 GHz, but works well at 18, and sometimes even up to 24 GHz. This connector is often used in avionics, radar, and microwave communications.
The SMC (Subminiature C) connector is a small, screw-on version of the SMA. It uses a 10–32 threaded interface and can be used in frequencies up to 10 GHz. This connector is used primarily in microwave environments.
The SMB (Subminiature B) connector is a small version of the SMC connector. It was developed in the 1960s and features a snap-on coupling for fast connections. It features a self-centering outer spring and overlapping dielectric. It is rated from 2–4 GHZ, but can possibly work up to 10 GHz.
The MCX (Micro Coax) connector is a coax RF connector developed in the 1980s. It has a snap-on interface and uses the same inner contact and insulator as the SMB connector but is 30% smaller. It can be used in broadband applications up to 6 GHz.
Black Box Explains... Using 24- and 70-VDC paging systems.
The size of your paging system and the distance to end devices determine whether you should use 24- or 70-volt power. In either system, speakers, horns, and other paging-related equipment... more/see it nowtap into points along the powering wiring. You usually determine the number of taps based on a flowchart compiled at the design stage. This chart takes into account how many amplifiers (if any) youll be using.
In 24-VDC systems, youre limited by how many taps you can put on a run, and the low voltage supports a much shorter distance than a 70-VDC system. For these reasons, 24-VDC systems typically suit smaller office paging systems.
In these limited-drop paging systems (with fewer than 20 speakers or horns), the devices dont require a lot of source power because theyre self-amplified devices. Their amplifiers are either built in or are mounted near the speaker.
And because youre using much lower power, you can run power wiring alongside telephone-type wiring and not worry about ambient noise affecting your voice communications.
In contrast, 70-volt systems depend on central amplifiers to distribute power to speakers that have their own transformers. These stepdown transformers adapt the voltages of the signal from the central amplifier to the current required by the individual speaker.
The higher-voltage, lower-current system best suits connections to speakers distributed over a greater area.
In addition, you can adapt the wattage of speakers used in a 70-VDC system to match the sound requirements of the application. You can do this through the connections on the stepdown transformer, which you adjust to determine the amount of amplified power it draws from the central amplifier, so energy isnt wasted and speakers dont overheat and fail. Configuring a speaker transformer for lower power consumption, for example, is suitable for areas with low ambient noise.
A 70-VDC system also often works with amplifiers that have various types of inputs, so you can connect different types of paging and audio equipment. collapse