With the requirement of high-speed Ethernet in data center, the migration from 10G to 40G is beginning. Fanout technology has been widely applied in 40G data center to get higher data rate and higher port density. The principle of fanout technology is just like the water pipeline in a building. Water is transferred from the trunk pipeline, and then trunk pipeline fans out into several pipelines that have smaller diameters to bring the water to every house.
A device needing to be connected to two or several devices with different physical interface is very common. So the superiority of fanout technology is brought into full play, especially in the distribution layer of 40G data center and adapting lower data rate to 40G in cabling. Several widely used fanout/breakout assemblies in 40G data center will be introduced in this article.
A MPO fanout cable is a multi-fiber optical cable containing several individual tight buffered optical fibers with one end terminated with a male or female MPO connector and the other end usually terminated with several LC connectors.
Figure 1
Various MPO fanout cables are available in the market now. The fanout/breakout cable which is able to fan out into 12 or 24 fibers is most commonly used in 40G cabling deployment.
Figure 1 shows a typical 12-fiber MPO breakout cable (also called MPO harness cable) with OM3 optical fiber as the transmission media. This 12-fiber MPO fanout cable is terminated with a male MPO connector on one end and 6 duplex LC connectors on the other end. It can work from MPO trunk backbone assemblies to LC fiber rack system in high density backbone cabling from 40G device to 10G devices.
There is also a little bit smaller MPO fanout cable, of which the fibers fan out directly from the MPO connectors. This mini MPO harness cable can be easily put into patch panel and increase the cabling density effectively (see Figure 2).
Figure 2
MPO cassette is another special type of MPO fanout cable. It is designed for those who want to have everything in neat and tidy. The MPO cassette breaks the traditional design of the fanout cable. It can offer better cable protection and management by housing one or several mini size MPO fanout cables in a cassette. For a 12-fiber MPO cassette, there will be a 12-fiber mini direct fanout MPO cable inside the cassette. With one MPO in the back side of the cassette and six duplex LC connectors in the front (see Figure 3).
This type of cassette can be installed in the standard rack in data center. To achieve higher cable density, more 12-fiber or 24-fiber mini MPO fanout cables are installed for 40G transmission. For instance, Figure 3 is a 24-fiber MPO cassette containing two 12-fiber fanout cables, thus there are two 12-fiber MPO connectors on the cassette. A 24-fiber MPO cassette can also have a mini size 24-fiber fanout cable inside the cassette. This cassette will only have one 24-fiber MPO connector in the back side. No matter what the fiber count and connector type are, these MPO cassettes can be customized in Fiberstore according to your requirements.
Figure 3
By offering direct interconnection for devices in data center, direct attach cable also has fanout design. Converting one form factor to a different form factor is necessary in many cases. For instance, a 40G device may be connected to one or several 10G devices for distribution or adapting. With fanout direct attach cable, this process would be much easier. This pre-terminated components can also increase the reliability of data center effectively.
A 40G direct attach cable usually has a 40G QSFP+ connector on one end, no matter it uses copper or fiber as the transmission media. And four 10G XFP connectors or four 10G SFP+ connectors are terminated on the other end of the 40G direct attach cable.
Figure 4
Sometimes it also needs to convert QSFP+ to LC interface. There is also another type of 40G DAC can satisfy this requirement. This kind of DAC is attached with a QSFP+ on one end and several LC connectors on the other end (see Figure 4). Figure 4 shows an active optical cable (AOC) with one end plugged into a QSFP+ switch and the other end attached with four duplex LC connectors which are separately linked to four 10G SFP+ transceivers. These 10G transceivers are then plugged into 10G switch with SFP+ ports. In this way, 40G cabling to 10G cabling is achieved.
Fanout technology is playing an important role in 40G data center. Products like 40G break out cable, cassette and 40G break out direct attached cable can all be found and customized in Fiberstore. Different connectors, cable length, fiber count etc. can all be specially designed according to your application. Please contact sales@fs.com for more details about fanout products in 40G data center.