Black Box Explains...Multimode vs. single-mode Fiber.
Multimode, 50- and 62.5-micron cable.
Multimode cable has a large-diameter core and multiple pathways of light. It comes in two core sizes: 50-micron and 62.5-micron.
Multimode fiber optic cable can be... more/see it nowused for most general data and voice fiber applications, such as bringing fiber to the desktop, adding segments to an existing network, and in smaller applications such as alarm systems. Both 50- and 62.5-micron cable feature the same cladding diameter of 125 microns, but 50-micron fiber cable features a smaller core (the light-carrying portion of the fiber).
Although both can be used in the same way, 50-micron cable is recommended for premise applications (backbone, horizontal, and intrabuilding connections) and should be considered for any new construction and installations. Both also use either LED or laser light sources. The big difference between the two is that 50-micron cable provides longer link lengths and/or higher speeds, particularly in the 850-nm wavelength.
Single-mode, 8–10-micron cable.
Single-mode cable has a small, 8–10-micron glass core and only one pathway of light. With only a single wavelength of light passing through its core, single-mode cable realigns the light toward the center of the core instead of simply bouncing it off the edge of the core as multimode does.
Single-mode cable provides 50 times more distance than multimode cable. Consequently, single-mode cable is typically used in long-haul network connections spread out over extended areas, including cable television and campus backbone applications. Telcos use it for connections between switching offices. Single-mode cable also provides higher bandwidth, so you can use a pair of single-mode fiber strands full-duplex for up to twice the throughput of multimode fiber.
Specification comparison:
50-/125-Micron Multimode Fiber
850-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 550 m;
1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 550 m
62.5-/125-Miron Multimode Fiber
850-nm Wavelength:
Bandwidth: 160 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 220 m;
1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 500 m
8–10-Micron Single-Mode Fiber
Premise Application:
Wavelength: 1310 nm and 1550 nm;
Attenuation: 1.0 dB/km;
Outside Plant Application:
Wavelength: 1310 nm and 1550 nm;
Attenuation: 0.1 dB/km collapse
Black Box Explains...Multimode vs. single-mode Fiber.
Multimode, 50- and 62.5-micron cable.
Multimode cable has a large-diameter core and multiple pathways of light. It comes in two core sizes: 50-micron and 62.5-micron.
Multimode fiber optic cable can be used for most general data and voice fiber applications, such as bringing fiber to the desktop, adding segments to an existing network, and in smaller applications such as alarm systems. Both 50- and 62.5-micron cable feature the same cladding diameter of 125 microns, but 50-micron fiber cable features a smaller core (the light-carrying portion of the fiber).
Although both can be used in the same way, 50-micron cable is recommended for premise applications (backbone, horizontal, and intrabuilding connections) and should be considered for any new construction and installations. Both also use either LED or laser light sources. The big difference between the two is that 50-micron cable provides longer link lengths and/or higher speeds, particularly in the 850-nm wavelength.
Single-mode, 8–10-micron cable.
Single-mode cable has a small, 8–10-micron glass core and only one pathway of light. With only a single wavelength of light passing through its core, single-mode cable realigns the light toward the center of the core instead of simply bouncing it off the edge of the core as multimode does.
Single-mode cable provides 50 times more distance than multimode cable. Consequently, single-mode cable is typically used in long-haul network connections spread out over extended areas, including cable television and campus backbone applications. Telcos use it for connections between switching offices. Single-mode cable also provides higher bandwidth, so you can use a pair of single-mode fiber strands full-duplex for up to twice the throughput of multimode fiber.
Specification comparison:
50-/125-Micron Multimode Fiber
850-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 550 m;
1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 550 m
62.5-/125-Miron Multimode Fiber
850-nm Wavelength:
Bandwidth: 160 MHz/km;
Attenuation: 3.5 dB/km;
Distance: 220 m;
1300-nm Wavelength:
Bandwidth: 500 MHz/km;
Attenuation: 1.5 dB/km;
Distance: 500 m
8–10-Micron Single-Mode Fiber
Premise Application:
Wavelength: 1310 nm and 1550 nm;
Attenuation: 1.0 dB/km;
Outside Plant Application:
Wavelength: 1310 nm and 1550 nm;
Attenuation: 0.1 dB/km
Black Box Explains...DDS vs. T1.
DDS (Digital Data Service) is an AT&T® service that transmits data digitally over dedicated leased lines. DDS lines use four wires, and support speeds up to 56 kbps; however, DDS... more/see it nowis actually a 64-kbps circuit with 8 kbps being used for signaling. You can also get 64-kbps (ClearChannel™) service. Since the transmission is digital, no modems are needed. Dedicated digital lines are ideal for point-to-point links in wide-area networks.
T1 is a dedicated transmission line operating at 1.544 Mbps. It’s comprised of 24 DSOs, each supporting speeds of 64 kbps. The user sends data at N x 56 or N x 64 over T1 circuits. T1 operates over twisted-pair cable and is suitable for voice, data, and image transmissions on long-distance networks. collapse
Black Box Explains...DDS vs. T1.
DDS (Digital Data Service) is an AT&T® service that transmits data digitally over dedicated leased lines. DDS lines use four wires, and support speeds up to 56 kbps; however, DDS is actually a 64-kbps circuit with 8 kbps being used for signaling. You can also get 64-kbps (ClearChannel™) service. Since the transmission is digital, no modems are needed. Dedicated digital lines are ideal for point-to-point links in wide-area networks.
T1 is a dedicated transmission line operating at 1.544 Mbps. It’s comprised of 24 DSOs, each supporting speeds of 64 kbps. The user sends data at N x 56 or N x 64 over T1 circuits. T1 operates over twisted-pair cable and is suitable for voice, data, and image transmissions on long-distance networks.
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 cable’s 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 eye’s 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 it’s 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... 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. And too much tension or stress on the jacket, as well as too tight of a bend radius, can damage the fiber core. If the cable’s 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 eye’s 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 it’s 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.
Black Box Explains...Ethernet InterRepeater Links
All Ethernet topologies allow a maximum of two IRL (InterRepeater Links) between any two devices. A 10BASE-T Hub counts as a repeater.
For more information, call our FREE Tech Support.
Black Box Explains...Benefits of T1 and E1.
If you manage a heavy-traffic data network and you demand high bandwidth for high speeds, Black Box has what you need to send your data digitally over super-fast T1 or... more/see it nowE1 communication lines.
Both T1 and E1 are foundations of global voice communication.
Developed more than 30 years ago and commercially available since 1983, T1 and E1 go virtually anywhere phone lines go, but faster.
T1 sends data up to 1.544 Mbps. E1 supports speeds to 2.048 Mbps. No matter where you need to connect—North, South, or Central America, Europe, or the Pacific Rim—T1 and E1 can get your data there—fast!
Both services provide flexibility for a multitude of applications.
Whether you need to drive a private, point-to-point line or a high-speed circuit; provide corporate access to the Internet or inbound access to your own webserver; or support a voice/data/fax/video WAN that extends halfway around the world, T1 or E1 can make the connection.
Both offer cost-effective connections.
In recent years, competition among telco service providers has led to increasingly more affordable prices for T1 and E1 services. In fact, most companies seriously considering a shift to T1 or E1 find they can negotiate even better rates with just a little comparative cost analysis.
Typical applications:
• Trunking of V.90 and ISDN remote connection to a central location.
• Accessing public Frame Relay networks for voice, fax, and data.
• Merging voice and data traffic. A single T1 or E1 line can give you several additional voice and data lines at no additional cost.
• Making LAN connections. If you’re linking LANs, a T1 or E1 line offers excellent performance.
• Sending bandwidth-intensive data such as CAD/CAM, MRI, CAT-scan images, and other graphics with large files. collapse
Black Box Explains...Benefits of T1 and E1.
If you manage a heavy-traffic data network and you demand high bandwidth for high speeds, Black Box has what you need to send your data digitally over super-fast T1 or E1 communication lines.
Both T1 and E1 are foundations of global voice communication.
Developed more than 30 years ago and commercially available since 1983, T1 and E1 go virtually anywhere phone lines go, but faster.
T1 sends data up to 1.544 Mbps. E1 supports speeds to 2.048 Mbps. No matter where you need to connect—North, South, or Central America, Europe, or the Pacific Rim—T1 and E1 can get your data there—fast!
Both services provide flexibility for a multitude of applications.
Whether you need to drive a private, point-to-point line or a high-speed circuit; provide corporate access to the Internet or inbound access to your own webserver; or support a voice/data/fax/video WAN that extends halfway around the world, T1 or E1 can make the connection.
Both offer cost-effective connections.
In recent years, competition among telco service providers has led to increasingly more affordable prices for T1 and E1 services. In fact, most companies seriously considering a shift to T1 or E1 find they can negotiate even better rates with just a little comparative cost analysis.
Typical applications:
• Trunking of V.90 and ISDN remote connection to a central location.
• Accessing public Frame Relay networks for voice, fax, and data.
• Merging voice and data traffic. A single T1 or E1 line can give you several additional voice and data lines at no additional cost.
• Making LAN connections. If you’re linking LANs, a T1 or E1 line offers excellent performance.
• Sending bandwidth-intensive data such as CAD/CAM, MRI, CAT-scan images, and other graphics with large files.
Black Box Explains...Ceramic and composite ferrules.
Cables manufactured with ceramic ferrules are ideal for mission-critical applications or connections that are changed frequently. These cables are high quality and typically have a very long life. Ceramic ferrules... more/see it noware more precisely molded and fit closer to the fiber than their composite counterparts, which gives them a lower optical loss.
On the other hand, cables with composite ferrules are ideal for less critical applications or connections that won’t be changed frequently. Composite ferrule cables are characterized by low loss, good quality, and long life. collapse
Black Box Explains...Ceramic and composite ferrules.
Cables manufactured with ceramic ferrules are ideal for mission-critical applications or connections that are changed frequently. These cables are high quality and typically have a very long life. Ceramic ferrules are more precisely molded and fit closer to the fiber than their composite counterparts, which gives them a lower optical loss.
On the other hand, cables with composite ferrules are ideal for less critical applications or connections that won’t be changed frequently. Composite ferrule cables are characterized by low loss, good quality, and long life.
Black Box Explains...Remote Access Servers.
Remote access servers (RASs) are high-level intelligent devices with multiple asynchronous communication ports that connect to modems and provide remote users with dial-in access to a central site network.
You... more/see it nowcan configure your RAS to operate via remote control or remote node access.
Remote control operation enables remote users to send keystroke data and receive screen output from the central site. The actual processing takes place inside the communication server. Remote node access enables the remote user to become a network node and all remote workstations to function as if they were connected locally.
A fixed-port remote access server has a network connection to your LAN and one or more asynchronous RS-232 ports that connect to external modems. It usually comes equipped with 4, 8, or 16 async ports and is easy to install, support, and maintain. These devices are ideal for traveling workers who don’t have a remote office but who need connections to the corporate network for short periods of time.
For configuration flexibility, scalability, and remote wide-area connection options, choose a modular remote-access server that you can change as your network grows. Most modular RASs accept a variety of modules, including:
• High-density async RS-232 modules that connect to external modems or ISDN terminal adapters. These modules typically have eight or more ports.
• High-density modem modules that usually incorporate eight modems on a single card, enabling you to consolidate equipment costs, increase reliability, and simplify management.
• Digital modules that enable you to make direct connections to high-speed digital lines. Instead of using multiple dialup lines, you can use these devices to bring a single high-speed digital phone line—known as a channelized T1— to your equipment.
The best way to determine what type of RAS you need—or whether you need a router or a RAS—is to identify what remote solution will meet your connectivity requirements. If you’re not sure what you need, contact our FREE Tech Support. collapse
Black Box Explains...Remote Access Servers.
Remote access servers (RASs) are high-level intelligent devices with multiple asynchronous communication ports that connect to modems and provide remote users with dial-in access to a central site network.
You can configure your RAS to operate via remote control or remote node access.
Remote control operation enables remote users to send keystroke data and receive screen output from the central site. The actual processing takes place inside the communication server. Remote node access enables the remote user to become a network node and all remote workstations to function as if they were connected locally.
A fixed-port remote access server has a network connection to your LAN and one or more asynchronous RS-232 ports that connect to external modems. It usually comes equipped with 4, 8, or 16 async ports and is easy to install, support, and maintain. These devices are ideal for traveling workers who don’t have a remote office but who need connections to the corporate network for short periods of time.
For configuration flexibility, scalability, and remote wide-area connection options, choose a modular remote-access server that you can change as your network grows. Most modular RASs accept a variety of modules, including:
• High-density async RS-232 modules that connect to external modems or ISDN terminal adapters. These modules typically have eight or more ports.
• High-density modem modules that usually incorporate eight modems on a single card, enabling you to consolidate equipment costs, increase reliability, and simplify management.
• Digital modules that enable you to make direct connections to high-speed digital lines. Instead of using multiple dialup lines, you can use these devices to bring a single high-speed digital phone line—known as a channelized T1— to your equipment.
The best way to determine what type of RAS you need—or whether you need a router or a RAS—is to identify what remote solution will meet your connectivity requirements. If you’re not sure what you need, contact our FREE Tech Support.
Black Box Explains...Cable termination.
Carefully remove the jacketing from the cable and expose one inch of the insulated wire conductors. Do not remove any insulation from the conductors. When the... more/see it nowRJ-45 connector is crimped, the contacts inside will pierce the conductor insulation.
Untwist the wires to within 1/8" of the jacket. Arrange the wires according to the cable spec (568B in this case). Flatten and align the wires. Make one straight cut across all the conductors, removing approximately 1/2" to ensure the ends are of equal length.
Slide the wires into a connector. The cable jacket should extend into the connector about 1/4" for strain relief. Orient the wires so connector Pin 1 aligns with cable Pin 1, etc. Hold the connector in front of you. With the locking tab down, Pin 1 is on the far left.
Insert the connector into a crimp tool. Make sure you’re using the proper die. Firmly squeeze the handles. They’ll lock in a ratcheting action. A final click indicates the connector is firmly latched.
Check your work using a continuity tester or cable certifier rated for the cable standard you’re installing. Your tester should be able to check for shorts, opens, or miswires.
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Black Box Explains...Cable termination.
Carefully remove the jacketing from the cable and expose one inch of the insulated wire conductors. Do not remove any insulation from the conductors. When the RJ-45 connector is crimped, the contacts inside will pierce the conductor insulation.
Untwist the wires to within 1/8" of the jacket. Arrange the wires according to the cable spec (568B in this case). Flatten and align the wires. Make one straight cut across all the conductors, removing approximately 1/2" to ensure the ends are of equal length.
Slide the wires into a connector. The cable jacket should extend into the connector about 1/4" for strain relief. Orient the wires so connector Pin 1 aligns with cable Pin 1, etc. Hold the connector in front of you. With the locking tab down, Pin 1 is on the far left.
Insert the connector into a crimp tool. Make sure you’re using the proper die. Firmly squeeze the handles. They’ll lock in a ratcheting action. A final click indicates the connector is firmly latched.
Check your work using a continuity tester or cable certifier rated for the cable standard you’re installing. Your tester should be able to check for shorts, opens, or miswires.
Black Box Explains...Low-profile PCI serial adapters.
Ever notice that newer computers are getting smaller and slimmer? That means regular PCI boards won’t fit into these computers’ low-profile PCI slots. But because miniaturization is the rage in... more/see it nowall matters of technology, it was only a short matter of time before low-profile PCI serial adapters became available—and Black Box has them.
Low-profile cards meet the PCI Special Interest Group (PCI-SIG) Low-Profile PCI specifications, the form-factor definitions for input/output expansion. Low-Profile PCI has two card lengths defined for 32-bit bus cards: MD1 and MD2. MD1 is the smaller of the two, with cards no larger than 4.721 inches long and 2.536 inches high. MD2 cards are a maximum of 6.6 inches long and 2.536 inches high.
BLACK BOX® Low-Profile Serial PCI cards comply with the MD1 low-profile specification and are compatible with the universal bus. Universal bus is a PCI card that can operate in either a 5-V or 3.3-V signaling level system. collapse
Black Box Explains...Low-profile PCI serial adapters.
Ever notice that newer computers are getting smaller and slimmer? That means regular PCI boards won’t fit into these computers’ low-profile PCI slots. But because miniaturization is the rage in all matters of technology, it was only a short matter of time before low-profile PCI serial adapters became available—and Black Box has them.
Low-profile cards meet the PCI Special Interest Group (PCI-SIG) Low-Profile PCI specifications, the form-factor definitions for input/output expansion. Low-Profile PCI has two card lengths defined for 32-bit bus cards: MD1 and MD2. MD1 is the smaller of the two, with cards no larger than 4.721 inches long and 2.536 inches high. MD2 cards are a maximum of 6.6 inches long and 2.536 inches high.
BLACK BOX® Low-Profile Serial PCI cards comply with the MD1 low-profile specification and are compatible with the universal bus. Universal bus is a PCI card that can operate in either a 5-V or 3.3-V signaling level system.
Black Box Explains... Why media converters need SNMP.
The number of Ethernet switches and fiber optic segments being added to Ethernet networks keeps increasing. And as long as most Ethernet switches are only available with 10BASE-T and 100BASE-TX... more/see it nowinterfaces, media converters will remain in demand.
Until now, a failure on the network could go unnoticed. Once a failure was detected, it could take a long time to isolate it, especially if a technician had to be sent to the site. But media converters with SNMP eliminate some of the guesswork.
With SNMP, the IS manager can detect a failure, isolate it to a specific port, and determine what hardware is required to repair it. A technician can then be sent directly to the right place to fix faulty hardware or repair a broken cable.
SNMP enables you to set up alarms or traps when a link is down. You can turn features on and off from a central terminal, so there’s no need to leave your desk. You can also monitor power supplies and replace them without interrupting service. SNMP management reduces the time and money it takes to get your network up and running again. The users on your network will notice—and appreciate—the improved service and reliability. collapse
Black Box Explains... Why media converters need SNMP.
The number of Ethernet switches and fiber optic segments being added to Ethernet networks keeps increasing. And as long as most Ethernet switches are only available with 10BASE-T and 100BASE-TX interfaces, media converters will remain in demand.
Until now, a failure on the network could go unnoticed. Once a failure was detected, it could take a long time to isolate it, especially if a technician had to be sent to the site. But media converters with SNMP eliminate some of the guesswork.
With SNMP, the IS manager can detect a failure, isolate it to a specific port, and determine what hardware is required to repair it. A technician can then be sent directly to the right place to fix faulty hardware or repair a broken cable.
SNMP enables you to set up alarms or traps when a link is down. You can turn features on and off from a central terminal, so there’s no need to leave your desk. You can also monitor power supplies and replace them without interrupting service. SNMP management reduces the time and money it takes to get your network up and running again. The users on your network will notice—and appreciate—the improved service and reliability.