The cable enables data center operators to split 40G switch and router ports into four separate 10G connections for applications that require longer reach than the 300 m supported by multimode fiber. Thanks to the use of an integrated 40G CWDM multiplexer, the cable can support runs of 10 or 40 km, depending upon the optical transceiver used.
Data center operators use 40G switches to increase port density, as the switches support the configuration of each 40G port to act as four individual 10G ports. However, although the switch port is configured as if it were virtually four 10G ports, it physically remains one port. Such ports typically conform to the QSFP+ standard, for which only 40GBase-SR/LR/ER optical interfaces exist.
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In multimode applications, the transceiver already features four duplex fiber input/outputs, so only a cable or connector adaption is required. Singlemode versions are based on four different wavelengths that are multiplexed (and de-multiplexed at the other end), into one fiber output/input.
For these applications, the break out cable needs to not only adapt to different connectors but also feature the matching optical multiplexer inside the cable to mux and demux the four lambdas, Cube Optics points out. The new break-out cables have such a capability, based on Cube Optics’ proprietary compact multiplexer/demultiplexer technology.