Adding Fiber

For many years, I’ve wanted to upgrade the long runs of Ethernet cable from my home’s central switch to instead use fiber optic cable. Not only is fiber immune from electrical noise (why do electricians insist on running their Romex right next to the CAT 5E cable?), but it’s safe from power surges (one such surge toasted the Ethernet adapter on a piece of equipment in my former house) and isn’t subject to RFI from my radio station. Switching to fiber has been on my “to do” list for many years, and I’ve had a pile of RJ45 to fiber optic adapters in my Amazon “Save for Later” list for longer than I can remember.

After moving to my new house, I just wanted to get some hard-wired Ethernet installed (the previous owners had just used WiFi), and so running fiber was not foremost in my mind. I simply bought a box of CAT 5E cable and some RJ45s and pulled it wherever I needed it. Wife happily on Zoom. My home office happily accessing The Cloud. All good. Job done. On with life.

After I got back into ham radio, and started using my new FlexRadio, I returned to hanging out in the FlexRadio online community. It was there that the topic of fiber came up, and one of the posters mentioned a few pieces of fiber gear that he’s happy with. That rekindled my interest in fiber.

It turns out that over the past few years, probably with the more widespread adoption of fiber to the home (FTTH), fiber optic gear of all types from the cables themselves to converters and switches, has become widely available and very reasonably priced. Switches with 2GBE ports and slots for SFP transceiver modules are readily available on Amazon from reputable companies (see below for a rant on cheap switches) and cost less than $100.

Still, there have traditionally been several disadvantages to using fiber in a do-it-yourself home environment. Unlike Ethernet cable, it’s impractical to terminate at home. Also, fiber has historically been fragile: You had to be super careful when pulling it (in fact, many pros didn’t “pull” fiber optic cable at all, they “blew” it down conduits) and you needed to be wary of the minimum bend radius. In short… running fiber around your basement and through your walls has traditionally been no fun.

But since FTTH has become more common, many of these disadvantages have been overcome. Highly flexible fibers, like Corning ClearCurve, have reduced the minimum bend radius to as little as 5mm (0.2 inches). And armored cable, that wraps the fiber itself in a Kevlar-covered flexible stainless-steel jacket, is now widely available. You can actually pull this stuff without fear of fracturing the fiber within!

Fragile fiber? Not anymore! Armored cable to the rescue.

Not everything has changed. Unless you want to invest a good amount of money, and even more time practicing, it’s still impractical to terminate your own fiber optic cables. However, pre-terminated armored fiber cables are available on Amazon for less than US$0.30 per foot. I’ve used, and particularly liked, the cables on Amazon that are made by Bangun. The sheath on these cables is super slick and slides easily over just about anything, making pulling a breeze. Having said that, I will note that the connectors on these cables aren’t the greatest. But they seem to work fine.

Another thing I had to figure out for installing my fiber runs was how to affix the fiber to the walls and beams in my basement. I’ve always stapled Ethernet cable into place using “cable staples” — but stapling fiber optic cable, even cool armored fiber optic cable, just didn’t feel right to me. So, I got some cable clips like those that people use to tidy runs of computer cables. These have a wide surface and don’t snug down too tightly.

Cable clips to attach those armored fiber optic cables

To complete my infrastructure, I grabbed a couple of TrendNet switches (a ten port managed switch and a 6 port unmanaged switch) and, just to change things up a bit, a NetGear unmanaged switch. These supported 2.5Gb Ethernet over CAT 5E, which my Xfinity gateway also supports.

Aside: Please Choose a Trustworthy Brand for Your Switches!

There are a lot of no-name switches available on Amazon and Alibaba and who-knows-where else on the Internet. Almost all of them are made in China. Almost none of them have any "safety" markings (UL, CE, CSA or similar). Over the past many years, Chinese commodity network components (from digital picture frames to routers to webcams) have been time and again tied to security vulnerabilities (at least) and outright cyber-attacks (at worst). Don't open yourself or your neighbors up to this kind of misery.

Chinese electronics are already ubiquitous (do you know where your TV was made?) and I can't hope to eliminate every possible cyber-threat in my home or office. However, I strive to only use TAA and NDAA compliant products in my home and work networking infrastructure. 

I installed Ubiquiti SFP transceiver modules in the switches to support 1Gb fiber connections. I could have chosen to use 10Gb transceivers, but 90% of the traffic in my house is from an end-system to the Internet, and my Internet connection is limited to just over 1.2Gbps at the best of times. So, using a 10Gb fiber connections would have gained nothing (other than making the switches work harder and use more power).

Ubiquiti SFP transceivers… Single Mode BiDi… 1Gb speed

Aside: After posting that rant above, it’s come to my attention that the 1Gb Ubiquiti modules I bought may not be TAA compliant. The country of origin is, suspiciously, nowhere to be found on the modules themselves or their packaging. While I continue to look into this, at least I’m reassured that these are simple electronic modules… and not stand-alone devices with processing power.

There are a lot of choices and options when it comes to fiber optic equipment. It took me a long time to figure out what type of fiber and connectors I wanted to use (in truth, reading about all this stuff was part of the fun). In the end, I decided on using simplex bi-directional fiber connections (what the pros call BiDi or WDM for “Wave Division Multiplexing”). In these connections, only a single fiber is used to support two way traffic. Traffic in one direction happens at 1310nm, and traffic in the other direction uses 1550nm. The exact wavelengths differ among transceiver vendors, and you need to buy the SFP transceiver modules in pairs (hence the yellow and blue markings on Ubiquiti the modules in the picture). I figured that using a single fiber, as opposed to a pair, would be easier and cheaper. And I’ve had no problems… at least so far.

And, in the end, after many years of wanting to do so, I now have fiber optic cable running through my home, and isolating my lab and radio room from electrical and RF interference. I have no idea if this makes any practical difference… but it was definitely a fun project.