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Product Data Sheets (pdf)...Modular Fiber Switches

  • Firmware... 
  • 52-Port Gigabit Ethernet Managed Switch
    Firmware for the LGB5052A (Version v2.00)
 

Product Data Sheets (pdf)...Gigabit L3 Managed Switches with 10G Uplinks


Product Data Sheets (pdf)...Palm-Sized Ethernet Switches,


Black Box Explains...PoE phantom power.

10BASE-T and 100BASE-TX Ethernet use only two pairs of wire in 4-pair CAT5/CAT5e/CAT6 cable, leaving the other two pairs free to transmit power for Power over Ethernet (PoE) applications. However,... more/see it nowGigabit Ethernet or 1000BASE-T uses all four pairs of wires, leaving no pairs free for power. So how can PoE work over Gigabit Ethernet?

The answer is through the use of phantom power—power sent over the same wire pairs used for data. 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.

10- and 100-Mbps PoE may also use phantom power. The 802.3af PoE standard for use with 10BASE-T and 100BASE-TX defines two methods of power transmission. In one method, called Alternative A, power and data are sent over the same pair. In the other method, called Alternative B, two wire pairs are used to transmit data, and the remaining two pairs are used for power. That there are two different PoE power-transmission schemes isn’t obvious to the casual user because PoE Powered Devices (PDs) are made to accept power in either format. collapse

  • Manual... 
  • PoE+ Gigabit Managed Switch Eco CLI Guide
    CLI Guide for the LPB2810A, LPB2826A, and LPB2848A (Version 1)
 
  • Manual... 
  • -Port PoE PD Switch (Unmanaged, 10BASE-T/100BASE-TX) Manual
    Manual for the LPE108AE (Version 1)
 

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. collapse


Product Data Sheets (pdf)...Gigabit Unmanaged Switches with SFP Uplinks


Product Data Sheets (pdf)...High-Density Media Converter System II

Results 51-60 of 81 << < 6 7 8 9 > 
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