Cabling Mistakes #9: Rely on Duplex Tester for MPO Cable Certification

While the smart people who install, test and certify network cabling plants know the importance of meeting standards performance parameters and ensuring application support, even the best of us can make mistakes that adversely impact the bottom line and customer satisfaction.

Let’s take a look at the #9 Dumb Thing that smart people do when testing network cabling systems—relying on a duplex tester for certifying MPO trunks.

Now the Challenging Norm

随着大数据的增加、虚拟化以及数据中心光纤主干链路带宽速度的提高（可达 40 甚至 100 Gbps），现在多数数据中心都在多芯插拔式 (MPO) 连接器解决方案的基础上进行标准化。While required testing of these 12-fiber MPO connectors may have been limited in the past, it is now the norm in the majority of data center installations. 现场测试是确保 MPO 链路符合应用性能需求的唯一方式。

尽管预端接的 MPO 光纤线缆由供应商生产并进行测试，符合 ANSI/TIA 和国际标准，但许多因素都可能会影响性能。First of all, MPO connectors are harder to clean than duplex connectors. The 12-fiber MPO interface features an array with a much larger surface area, which unfortunately makes it easier to move contaminants from one fiber to another within the same array during the cleaning process.  40 和 100 Gbps MPO 光纤应用的损耗预算也低很多，因此确保较高的测试精度至关重要。

The Problem with Duplex Testers

It seems only logical that testing a 12-fiber MPO fiber link with a duplex tester would be time consuming. In fact, it requires about 15 steps with a 3 jumper method and the use of MPO to LC fan-out cords that separate the 12-fiber cable into single fiber channels (or LC-MPO cassettes can be used if they have no more than a total loss of 0.35dB).

To test MPOs with a duplex tester, technicians first need to verify and set the SC-LC and LC-LC test reference cords. A third LC test reference cord then needs to be verified, set and removed before even connecting to the first pair of fibers on the MPOs—and there are 5 more pairs to be tested on both ends.

Not only is there a good chance that technicians pressed for time in the field will not follow all 15 steps, but the complex, time-consuming process inherently lends itself to the potential for greater inconsistencies—and it makes it more difficult to keep all the connectors clean during the process.

A Better Way

Testers with an on-board MPO connector take the complexity, time and inconsistency out of MPO testing—eliminating the need for the fan-out cord or cassette. Fluke Networks’ MultiFiber Pro is the first tester to offer this functionality with the ability to scan all 12 fibers simultaneously and display test results in an easy-to-read bar graph. The MultiFiber Pro even has the ability to identify each fiber of the MPO, providing more precise, per-fiber data and reporting to improve MPO connector verification and troubleshooting.

MultiFiber Pro even has the ability to test for correct polarity, which ensures a continuous connection from the transmitter to the receiver and requires patch cords with different polarity types depending on the chosen polarity method. MultiFiber Pro allows the user to test individual patch cords, permanent links, and channels for correct polarity—without needing prior knowledge of the link’s polarity.

The next time you think a duplex tester will suffice for your MPO testing, keep in mind that the innovative features of the MultiFiber Pro will eliminate the complexity and allow you to test 90% faster. And if you only have one MPO job for now, you can still save all that time by renting one – call us and we’ll set you up!