Now, it’s time to switch gears (again I picture my old GTO) from my first blog post and move to the fiber itself.  For typical 10G applications, OM3 multimode fiber was sufficient for even the largest data centers, supporting 10 gigabits per second out to 300 meters and similar distances for fibre channel. 

The new OM4 specification is embraced by the fibre channel committee to provide longer distance support for higher data rates such as 16Gig, 32Gig, etc, but there is also benefit on the Ethernet side.  The new standards for 40Gig and 100Gig Ethernet are set at 100 meters using OM3 fiber.  This means that for anything above 100 meters, you’d have to make the jump to singlemode transceivers on both ends of the link, which is an expensive proposition; more than a factor of 4X for every 40Gig link and a whopping factor of 10X for every 100Gig link.  With the new OM4 fiber, the distance limit extends out to 125 meters, or even 150 meters if connection loss is limited to 1.0dB.

Better, but perhaps still not long enough?  I think not. 

Some of this is limited by the loss of the typical MPO connection, which my previous blog post discusses.  When you’re trying to mate 12 fibers at once, tolerances become substantially more critical.  With truly low-loss MPO connections, coupled with (what I believe is) the best multimode fiber on the planet for these applications, 170 meters is possible today!

When trying to future-proof your infrastructure, I struggle to see a more powerful value proposition than the combination of OM4 and MPO-based architecture – in any media type – or for any application - period.  I hear the proverbial gauntlet hitting the floor – CLANG!

BTW – the movie references in the first blog post???  Bill Murray in “What About Bob” and Steve Martin in “The Pink Panther.”

About the Author

Simon Cowley

Simon C. Cowley is director of campus fiber market development for CommScope.  In this role, he is responsible for developing unique and comprehensive solutions for the office and campus workplace environment covering copper, fiber, wireless, and power technologies. Simon previously led CommScope’s Enterprise Solutions Global Technical Support team since 2006.  He also served as director of apparatus R&D for copper, fiber, and intelligent systems and fiber optic engineering manager since joining CommScope in 2001. Before joining Commscope, he served in various engineering, business development, and management capacities with Amphenol Fiber Optics, ITT Cannon, and FCI/Berg Electronics. Simon is a graduate of Rensselaer Polytechnic Institute with an MBA in Global Management from the University of Phoenix.

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Data Center Enterprise


2 comments for "MPO And OM4 Go The Distance"
Ahmed Abdallah Ibrahim

Thank you Simon, How can i plug MPO in SFP ports in Switch? Ahmed Abdallah Network Engineer CCNA & JNCIA-EX New Super Wave and Networks Authorized BusinessPartner for Systimax Solutions in Egypt

Simon Cowley

Hello Ahmed, it's really two different technologies. The 10G ports that you may see now with SFP ports are different than the 40G/100G ports in the equipment. The multimode SNAP-12 package is similar in size to a 10G SFP and actually much smaller than the comparative singlemode versions at 100G, even though the single mode uses only two fibers. Eventually, the switch vendors will be putting the SNAP-12 in place of SFP ports. Some 40G equipment has already been announced with 40G uplinks.

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