Supercharge your communications solutions to speed past copper cabling and multimode fiber's the bandwidth and distance limitations

Stock car racing is a lot like communication networks. Each race is a balance of speed and distance with each track posing different challenges to maintain your speed without crashing before the finish line.

Likewise, the communications cabling field is full of articles and presentations about souping up your lower speed network to Category 8 cable or multimode fiber (MMF) for a higher-speed network, whether it is 1 Gb/s to 10Gb/s up to 100Gb/s. I spend a good deal of time reading these publications and listening to presentations at BICSI events, and end up with the same conclusion: Why build a restrictor plate in your network?

Stuck at the starting line?

I am a Sr. Application Engineer and a BICSI Registered Communications Distribution Designer (RCDD), and I've seen a lot over my career. All the way back in 2012, I was vetting vendors for high density 10Gb/s with a path to 100Gb/s core, aggregation and edge one, when I saw a vendor demonstrate their 400Gb/s capability for an underlying Optical Transport Network. The connecting medium throughout both networks would be singlemode fiber. Multimode fiber was never really in the race, and Cat cable didn’t even qualify.

Today, as I travel and talk with data center managers, network managers, and designers, I see that many folks, just now, are understanding the limitations of copper Category cabling and multimode fiber. In the face of increasing bandwidth demands and distances, they're stuck at the starting line. The simple truth is singlemode fiber is the only full-throttle solution. It's the hot setup, as they say in the stock car racing world, to keep you in front of the pack.

Let’s say you are designing a campus network and determining what medium to specify: Category 5e/6/6a/now Cat 8 cable, multimode fiber, or singlemode fiber. Personally, I would never recommend or design around twisted copper pairs. (That's like recommending the most popular car engine from 2002 for a race next year.) Today, we have video chat, countless remote devices, and Smart TVs, with a standard 4K and soon 8K (then 16K) video resolution. Copper Category cable is a patch cord with no place in the distribution pathways.

What about Power over Twisted Pair? There are other options. Just ask your Optical Line Terminal (OLT)/Passive Optical Network (PON) equipment representative. Passive Optical LAN is continuing to gain ground over traditional Ethernet LAN. Take into consideration the sheer size and cumulative weight of a copper-based medium. It’s like racing in a garbage truck. Cat 8 cable is 10% larger in diameter than Cat 6a.

Check out the speed and distance chart and size comparison below. By simplifying the design, optical fiber cabling is mean, lean, and built for speed.

You may think multimode fiber is a viable option. And it is — if you want to limit your speed and distance. The demand on your networks are not slowing down and the distance to edge is being pushed farther out to support the increasing number of devices and services. Multimode restricts your network and increases the engineering effort to measure distances to the meter. You are creating unnecessary pit stops. Why put a governor on your network speed?

In the data center, you could utilize a multimode jumper intra-cabinet between the switch and the servers or between line-ups. This setup is sustainable for now with the new multimode Short Wavelength Division Multiplexing optics (SWDM) and OM5 fiber or with OM4 fiber utilizing 4 TX/RX channels on a MPO/MTP jumper. But we all know that 400Gb/s speeds and greater are coming soon.

If you have adopted OM4/OM5 in the permanent links, do you want to upgrade your fiber cabling again in 3 to 5 years to accommodate terabit speeds? OM5 does not give greater distance versus OM4. OM5 allows for multiplexing four wavelengths on an individual multimode fiber. This means a new color (lime green), a new pluggable and new technology, which ultimately means increased cost.

Singlemode fiber will support virtually any speed for kilometers while multimode fiber only supports certain speeds for meters. MMF is like putting soft tires on. Sure, you’ll go fast in the corners, but you'll only get a few laps for a limited distance.

Singlemode fiber crosses the finish line

Finally, there is singlemode fiber (SMF). Singlemode distances and speeds are basically limited only by the active gear you choose. The cable is less expensive than multimode fiber. Choosing a singlemode fiber allows options for GPON, Active Ethernet, DWDM, CWDM, and traditional Ethernet. That is: Do you want to let the cable in your network be a restrictor plate, limiting the type of services that can be deployed over it?

You have likely heard that singlemode pluggables are much more expensive, but that's not necessarily true today. The gap has narrowed and much depends on if you are deploying a pluggable from the OEM, a secondary vendor, or using fixed vs. tunable. Still concerned about cost? Take into consideration the cost of migrating off or removing a lesser cabling network 3 to 5 years down the road into your business case. Labor to remove an outdated medium is the true expense!

Clearfield can supply the complete hot setup of singlemode fiber that allows you to lead from start to finish. The options for building a network will come at you faster than the debris from the big one at Daytona. But my colleagues and I at Clearfield are here to be your spotters through the chaos.

Want to stay at the head of the pack? Tell Clearfield how we can help.

Marty Adkins, Sr. Application Engineer at Clearfield, is a BICSI RCDD and Telcordia GR1275-certified professional. With three decades in the telecommunications industry, Marty has extensive Data/Com experience in designing and constructing optical fiber infrastructure supporting multiple communications platforms, in addition to a background in network capacity planning and management. He presents on fiber optics topics at BICSI regional events and for various Clearfield customers.