Benefits of Using 8-Fiber Plug and Play MPO Solutions

The use of plug-and-play 12-fiber MPO solutions for multimode fiber backbones in the data center has been popular for several years, starting with 10 Gigabit Ethernet where 12-fiber MPO assemblies connect MPO-to-LC cassettes or modules that transition the 12-fiber MPO connections to 6 duplex LC connections.

There are several benefits to using preterminated plug-and-play MPO solutions, including faster deployment, reduced pathway fill and factory-terminated performance. Another reason for their popularity has been their ability to easily migrate to higher speed 40 and 100 Gigabit speeds that require MPO connectors by simply swapping out MPO-to-LC cassettes for MPO pass-through adapters.

Several cable and connectivity vendors are now offering 8-fiber MPO solutions for 40 and 100 Gigabit applications. Let's take a closer look.

Eliminate the Waste

Despite the benefits of preterminated cabling, 12-fiber MPO solutions waste 33% of the fiber when used for 40 and 100 Gigabit applications. That's because both 40GBASE-SR4 and 100GBASE-SR4 applications use only 8 of the 12 fibers--4 transmitting and 4 receiving at either 10 or 25 Mb/s. The other 4 fibers remain unused.

When 40 and 100 Gigabit deployments became a reality with active equipment using the MPO interface hitting the market, some connectivity vendors solved the problem of wasted fiber by using 24-fiber MPO assemblies with cassettes that transitioned to 8-fiber MPOs. Others offered hybrid patch cords with a single 24-fiber MPO that breaks out to three 8-fiber MPOs.

But these solutions had their own problems. Cassettes with a 24-fiber MPO to three 8-fiber MPOs introduced additional loss into a channel. The hybrid cords were difficult to manage, and they meant that if one 8-fiber MPO connection was damaged, all three ports had to be taken off line to replace the hybrid cord.

The Magic Number 8

To simplify 40 and 100 Gigabit deployments and have them more reliable and cost effective without the waste, cable and connectivity vendors now offer 8-fiber MPO solutions with 8-fiber trunk assembles and 8-fiber MPO connectivity.

What's important to know about these solutions is that they don't change the density--the 8-fiber MPO has the same footprint as the 12-fiber MPO. They can also still be used for 10 Gigabit applications with cassettes that transition an 8-fiber MPO to 4 duplex LCs.

But what about testing? Thankfully it too stays the same. That's right. Since 40 and 100 Gigabit applications only used 8 fibers of the 12-fiber MPO anyway, and the two connectors have the same footprint, nothing changes.

So go ahead and use your Fluke Networks' MultiFiber™ Pro Optical Power Meter and Fiber Test Kits just as you would for testing 12-fiber MPO channels. Whether there are 8 or 12 fibers , the MultiFiber Pro displays test results in an easy-to-read bar graph by scanning all fibers simultaneously. It even tests for correct polarity and can troubleshoot a single fiber within an MPO system.