Saved by the wire (and the fiber-optic cable)

You would never think that a wire could slow Internet speed. Well, perhaps you would think of that, but I hadn’t thunk about it much. I was once warned by my friend Eric that the wrong kind of wire could bring an Ethernet network to its knees. I knew he was right, but I didn’t act on it because it didn’t affect me. Until last week.

Ethernet, the electrical and electronic architecture that runs the Internet, runs on copper wire (mostly). Inside our offices and homes are kilometers of cables that deliver digital signals to our computers from nodes of the Internet far away.

In my home I have numerous computers, two printers, two Apple TV units, one Roku, and a device that reports from my roof-top solar panels. These are the wired connections, all of which use Ethernet. Unfortunately, our home was not wired with the Internet in mind. Though it’s a modern house, it has an older telephone wiring system. That has not been helpful in my networking efforts.

I have solved two problems with network wiring by using devices called Tendas. These take an Ethernet signal and put it onto the household electrical wiring. They cleverly deliver Ethernet where it is impossible to get wires; you plug a Tenda device into any electrical outlet, and then plug an Ethernet cable into that device. Elsewhere in the home you put another Tenda and pick up the signal there. With these devices I have Ethernet at my electrical utility box, and thus I can monitor my solar panels.

Apple’s USB-to-Ethernet adapter. It’s rated up to 100 Mbs. (Image from

A couple of weeks back my neighbor told us that she and her husband were on the new fiber-optic Internet service provided in our city by AT&T. I had seen men on fancy trucks pulling the fiber along the overhead lines a couple of summers ago, but I didn’t know it was ready for consumers. I was excited! Our Internet has been provided for the past 15 years by a local Internet Service Provider. It was bonded DSL, and the fastest speed we ever got was 32 Mbs down and 6.7 Mbs up, which is pretty poky. The alternative was the local cable TV supplier, whose offering is much faster, but famously unreliable.

Mbs is Megabits-per-second, the measurement unit of network speed. Divide that by 10* and you have Megabytes-per-second – approximately – and that tells you how fast your Internet connection is. On a 100 Mbs connection you can send and receive 10 megabytes per second. If you have a 25MB Photoshop file, it will take approximately 2.5 seconds to transmit the file over the Internet. That is acceptably fast in today’s world. AT&T’s fiber-optic is ten times faster than that, so the same 25MB file would take only 0.25 second to transmit. I was salivating!

I jumped. A call to AT&T got me started. Limits? Throttling? Extra fees for non-AT&T suppliers? No, no, and no. It seemed too good to be true.

I signed up, and three days later a team of skillful workers showed up at my house. They pulled the fiber through an underground conduit into the phone box on my house, then they drilled through the wall into a discreet spot behind my television and installed the gadget that converts the optical signal into an electrical signal. Then then routed that back out to the phone box, and somehow got the signal upstairs to my office, where they installed a modem and WiFi router.

In three days I went from 32 Mbs to 1000 Mbs signal speed. I was thrilled. The AT&T service is also half the price of my former service. I now get 30X speed at .5X price. You can’t beat that.

Apple’s Thunderbolt-to-Ethernet adapter. This one is rated to speeds up to 1000 Mbs. (Image:

Everything was moving faster except my primary computer, a Mac Pro (cylinder). With that machine I was getting only 67 Mbs after the fiber-optic install. My MacBook Air was getting a similar speed, but its Ethernet comes through a USB adapter (there is no Ethernet port on a MacBook Air). Even the new WiFi was faster than either of these, coming in at about 350 Mbs.

I started troubleshooting. Was it my 16-port Ethernet switch? Was it my Mac Pro? Did I have a defective connector? I started dragging wires around the office, draping them over tables and chairs, connecting this to that, and then that to this, and I discovered that my wife’s Mac Pro was running at 900 Mbs-plus while mine was clocking-in at a paltry 67 Mbs.

It was the wire.

I looked it up. There are three common wires used for Ethernet wiring: CAT-5, CAT-5E, and CAT-6. They have eight wires inside, each twisted in pairs, then co-twisted at very specific intervals to prevent cross-talk and electromagnetic induction. Though this is pretty esoteric, I realized that I must be a victim of induction-related trouble.

I installed a new Ethernet cable between the Switch and my computer, and it suddenly soared to 938 Mbs! Wow!

My cable had also been way too long, so I had coiled the left-over part into a nice 8-inch coil on the floor behind my computer. It turns out that this is a very bad idea since making a coil in a wire whose purpose is to prevent induction creates a big inductive opportunity. It’s better to have the cable go across the floor and never coil it up.

I also discovered that Apple makes an adapter to bring Ethernet into a MacBook Air through the Thunderbolt connector rather than through USB. I ordered one. When it arrived, I plugged it in and my MacBook jumped to a phenomenal 824 Mbs. This is 12 X the speed I got with the USB adapter. (Apple’s specification on the USB adapter says it goes to 100 BaseT which is only 100 Mbs, which explains the speed problem.)

Now all of our computers are running at full speed. Our TVs are happier, my solar panels are exactly the same, and my iPad is also happier. Everything is faster, and I am now a part of the digital community, no longer limping along with old technology

*The geeks reading this will quickly counter: No it’s not! It’s only eight bits per byte, etc. They are correct, but with what are called parity bits and checksum characters, it works out closer to ten, so I always figure that I should divide by ten. It works just as well, and it’s easier math.

About Brian Lawler

Brian Lawler is a Professor of Graphic Communication at California Polytechnic State University, San Luis Obispo. He writes about graphic arts processes and technologies for various industry publications, and on his blog, The Blognosticator.
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