Tag Archives: 12-fiber

MPO Cable Testing Overview

Nowadays, the existing bandwidth is not adequate to meet enterprises’ increasing appetite. In the meanwhile, optical technologies like cloud computing, virtualization and storage area networks are all in the fast development, which pushes the further development of higher-bandwidth tech like 40/100G Ethernet. Thus under this circumstance, new devices are greatly required. Besides the new optical transceivers and fiber optic cables, a steady proliferation of fiber connections—MPO (Multifiber Push-On) came into being.

MPO cables, featured by its compact, pre-terminated advantages, has become the default cabling solution for the increasing bandwidth requirements. However, a flaw of the MPO cable may hinder its development. The testing process of the MPO cable can be complex and error-prone. Have you been through the scene? When you prepare to test a MPO cable, you have to throw polarity of all 12 fiber connections into the mix. And if it comes to migrating 10 Gbps to 40/100 Gbps on the same cable, all the testing job you have done is in vain. Since the testing process is pretty uneasy, The following text will provide some detailed information about it to help you do the right MPO cable testing.

MPO cable

Problems You Should Know About MPO Cable Testing

Typically, a MPO cable contains 12 optical fibers, and each fiber is thinner than human’s hair. So if you want to test the cable, you must test every fiber of it, which is quite difficult for inexperienced engineers. The common way to do this is to use a fan-out cord to make the 12 fibers separate, then testing. One fiber testing would take you 10 seconds. So if your customer ask you to test 48 MPO trunks cable in data center which has a 30,000-MPO data center installation, that means you need to spend 3,120 hours. Such a huge project! To avoid this expensive and time-consuming process, modular factory-terminated MPO cables promise simplicity, lower cost, and true plug-and-play fiber connectivity.

Additional, when you are about to test a MPO cable, you should check whether the MPO cable is in the good state. Because cables must be transported, stored, and later bent and pulled during installation in the data center, which may lead to the performance uncertainties before fiber cables are deployed. Proper testing of pre-terminated cables after installation is the only way to guarantee performance in a live application.

What’s more, fiber polarity is also an important factor you should take into account. The simple purpose of any polarity scheme is to provide a continuous connection from the link’s transmitter to the link’s receiver. For array connectors, TIA-568-C.0 defines three methods to accomplish this: Methods A, B and C. Deployment mistakes are common because these methods require a combination of patch cords with different polarity types.

The Relationship Between Bandwidth and Testing

The market trend of telecom industry implies that 10G network has already been deployed in a large scale. And now 40G is main stream. As for 100G, people also already prepare for it. So bandwidth would always be a hot topic.

We have said before that MPO cable can solve the problem of bandwidth. As data center bandwidth steadily climbs to 10, 40, and 100Gbps, a dense multi-fiber cable becomes the only option. That’s why the use of MPO cables has steadily risen over the past 10 years. With the MPO cabling system, 40/100G migration path seems to be a simple and easy solution. Just remove the 10Gbps cassette from the MPO cable and replace it with a bulkhead accommodating a 40Gbps connection. Later it might be possible to remove that bulkhead and do a direct MPO connection for 100 Gbps at a later date. Figure 2 shows a 40G connectivity with the use of the 12-fiber MPO cable. A 40G QSFP like QSFP-40G-SR4 connects to a 12-fiber MPO cable. A 12-fiber MPO fanout cable is also used to connect four 10G SFP+ transceivers like 46C3447 with a MPO FAP.

40G connectivity

The problem is that while this migration strategy is an efficient way to leverage the existing cabling, in comparison to 10Gbps connections, the 40Gbps and 100Gbps standards call for different optical technology (parallel optics) and tighter loss parameters. In short, each time you migrate you need to verify the links to ensure the performance delivery the organization requires.

How to Do the Proper MPO Cable Testing

When you move to this part, you may think that MPO testing may be a tough obstacle for us to conquer. So is there a simple way to do the testing? The answer is yes. You can just test all 12 fibers—the whole cable—simultaneously and comprehensively (including loss and polarity). That sort of test capability changes the fiber landscape, enabling installers and technicians to efficiently validate and troubleshoot fiber—flying through the process by tackling an entire 12-fiber cable trunk with the push of a button.

MPO cable testing tool

To do a proper MPO cable testing, you must need some proper testing tools as shown in Figure 3. The tools to perform this type of test are emerging on the market, and promise to reduce the time and labor costs up to 95% over individual fiber tests. Characteristics to look for in such a tool include the following parts.

  • An onboard MPO connector to eliminate the complexity and manual calculations associated with a fan-out cord.
  • A single “Scan All” test function that delivers visual verification via an intuitive interface for all 12 MPO fibers in a connector.
  • Built-in polarity verification for end-to-end connectivity of MPO trunk cables.
  • “Select Individual Fiber” function that enables the user to troubleshoot a single fiber with more precision.

Summary

The insatiable need for bandwidth ensures that the integrity of the data center, which has also become inextricably linked to the strength of the fiber cabling infrastructure. Now more and more MPO trunk cables are put into use, to make sure the better performance, you should be able to test the MPO connection. Fiberstore offers a variety of MPO products including MPO trunk cables, MPO harness cable, 12-fiber or 24-fiber MPO cable and so on. All of our products can also be customized. Please feel free to contact us.

Choose 12-fiber or 24-fiber for 40/100G Migration

There is no doubt that 40 and 100 GbE are just around the corner, or the reality is coming. To keep up with the pace, data center managers are striving to determine which fiber optic links will support 10 GbE today while future proofing the best, most effective migration path to 40 and 100 GbE. Many network designers recommend that the use of 12-fiber multimode trunk cables can provide the best migration path to 40 and 100 GbE. While others confirm that 24-fiber trunk cables with 24-fiber MPOs on both ends is a better standards-based transition path. So which one is the most suitable solution? It all comes down to a brief comparison of these two cables over investment and reduced future operating and capital expense.

24-fiber Solution

The use of 24-fiber trunk cables between switch panels and equipment is a common-sense approach, but people may not be familiar with this optic scenario. In fact, a 24-fiber trunk cable is used to connect from the back of the switch panel to the equipment distribution area. For 10 GbE applications, each of the 24 fibers can be used to transmit 10 Gbps, for a total of 12 links. For 40 GbE applications, which requires 8 fibers (4 transmitting and 4 receiving), a 24-fiber trunk cable provides a total of three 40 GbE links. For 100 GbE, which requires 20 fibers (10 transmitting and 10 receiving), a 24-fiber trunk cable provides a single 100 GbE link as shown in Figure 1.

12-fibers

Maximum Fiber Utilization

As noted before, 40 GbE uses eight fibers of a 12-fiber MPO connector, leaving four fibers unused. When using a 12-fiber trunk cable, three 40 GbE links using three separate 12-fiber trunk cables would result in a total of 12 unused fibers, or four fibers unused for each trunk. But with the use of 24-fiber trunk cables, data center managers actually get to use all the fiber and leverage their complete investment. Running three 40 GbE links over a single 24-fiber trunk cable uses all 24 fibers of the trunk cable. Obviously, 24-fiber is more appropriate for 40/100G migration.

Increased Fiber Density

Because 24-fiber MPO connectors offer a small footprint, they can ultimately provide increased density in fiber panels at the switch location. With today’s large core switches occupying upwards of 1/3 of an entire rack, density in fiber switch panels is critical. Hydra cables feature a single 24-fiber MPO connector on one end and either 12 duplex LC connectors on the other end for 10 GbE applications, 12-fiber MPO connectors for 40 GbE or a 24-fiber MPO connector for 100 GbE. With a single 1RU fiber panel able to provide a total of 32 MPO adaptors, the density for 10 GbE applications is 384 ports in a 1RU (duplex LC connectors) and 96 40 GbE ports in a 1 RU (12-fiber MPOs). Figure 2 shows a 12-fiber MTP trunk cable with MTP/APC connector on both ends largely improves the performance for 40G/100G fiber links.

mtp-jumper-cable

Reduced Cable Congestion

Cable congestion is one of the biggest problems in the data center because it will make cable management more difficult and impede proper airflow needed to maintain efficient cooling and subsequent energy efficiency. In fact, a 24-fiber trunk cable are only appreciably larger than 12-fiber trunk cables in diameter. That means the 24-fiber trunk cables provide twice the amount of fiber in less than 21% more space. For a 40 GbE application, it takes three 12-fiber trunk cables to provide the same number of links as a single 24-fiber trunk cable—or about 1-1/2 times more pathway space.

Cost-effective Migration Path

As 24-fiber trunk cables can effectively support all three applications shown in Figure 3, there is no need to recable the pathways from the back of the switch panel to the equipment distribution area. That means that data center managers can easily migrate to higher speeds with all of that cabling remains permanent and untouched. With 24-fiber trunk cables offer guaranteed performance for 10, 40 and 100 GbE, upgrading the cabling infrastructure is as simple as upgrading the hydra cables or cassettes and patch cords to the equipment.

migration path from 10G to 40&100G

Conclusion

With guaranteed support for all three applications, the ability to use all the fiber deployed, reduced cable congestion and higher port density in fiber panels, and an easy migration scheme, 24-fiber trunk cables offers lower future capital and operating expense. Fiberstore supplies 12, 24, 48, 72, 96 and 144 fiber core constructions with OM1, OM2, OM3 or OM4 fiber trunk cable, these trunk cable assemblies are composed of high quality LSZH jacketed fiber optic cables, connecting equipment in racks to MTP/MPO backbone cables. 40G QSFP+ optical transceivers like FTL410QE2C and QSFP-40G-LR4-S are also provided. If you are interested in any of our products, please contact us directly.