There are two 40 Gigabit fiber optic physical medium dependent (PMD) specifications within the standard, which offer 40Gb/s Ethernet over multimode fiber optic (MMF) cable and single-mode fiber optic (SMF) cable. The 40GBASE-SR4 short reach fiber optic system sends four lanes of PCS data over four pairs of multimode cables, for a total of eight fiber strands. The 40GBASE-LR4 long-reach system sends four lanes of PCS data over four wavelengths of light, carried over a single couple of fiber optic cables.
The first 40G transceiver were based on the C form-factor pluggable (CFP) module, that is a large module capable of handling up to 24 watts of power dissipation. First-generation transceivers with multiple chips and bigger power requirements were according to this module. The CFP module is specified by a multiagreement.
Figure 1 shows a CFP 40G transceiver, that you can use to offer either a 40GBASE-SR4 or a 40GBASE-LR4 transceiver. The module shown with this figure is a 40GBASE-LR4 transceiver, which supplies two SC fiber optic connectors for link to a pair of single-mode fibers. The entire process of the 40GBASE-LR4 connection is described later in this particular chapter.
Figure 1 40GBASE-SR4 CFP 40G Transceiver
The most famous connector for 40Gb/s interfaces currently is the QSFP+ module: it requires up far less space on a switch or server interface, making it possible for vendors to offer multiple QSFP+ ports in the same space as a single CFP port. The 40G transceiver module for 40GBASE-SR4 is supplied with a multifiber push-on (MPO) media connector, carrying multiple pairs of fiber optic cables to support the four lanes of data for the short reach fiber standard. The 40GBASE-LR4 long-reach system uses a QSFP+ transceiver designed with a duplex fiber connector to connect for the single pair of fiber cables.
The MPO plug supports the eight fiber cables needed to supply a 40GBASE-SR4 connection, plus four fibers which are unused. The MPO plughas two alignment pins, that help keep each connector and it is fibers correctly aligned once the two connectors are mated. Also shown is an end-on have a look at a plug connector, which shows the 12 fibers arranged between the two alignment pins. Note that the important thing on the plug connector means that the plug connector might be correctly oriented from the socket.
Figure 2 shows a single-mode fiber optic cable terminated in an LC optical plug connector. Also shown is a 40G QSFP+ to 8 LC Connetor Breakout Active Optical Cable.
Figure 2 40GBASE QSFP+ to LC Connetor(8) Breakout Active Optical Cable
FS.COM optical cables could be ordered in specific lengths is actually specific connector types, as needed from your circumstances. If you’re connecting an optical jumper cable from the 40G QSFP+Transceiver module in a switch port straight to a server interface, you’ll need a brief cable using the correct cable connectors on each side. For 40GBASE-SR4, this cable might have MPO connectors on both ends. If you’re connecting a 40G Transceiver module in a switch port to an optical connector termination reason for your data center or cabling closet, the optical connectors in your termination point may be different from the ones suited for the 40G QSFP+ Transceiver module, requiring a cable having a different type of optical connector on both ends.