On a first look at CenturyLink gigabit fiber service in St. Paul, I was seeing speeds over Wi-Fi of typically 30 – 60 Mbps. Wresting more speed from the connection turned out to be simple.
Initial hardware setup after CenturyLink fiber installation (before I made the wires neat). The bottom diagram identifies the pieces and shows their interconnections. The “ONT” at the right is an optical network terminal, the fiber-to-ethernet converter.
I began to suspect that the main bottleneck in my initial setup (see the figure at right) was the 7-year-old Apple Time Capsule Wi-Fi access point and router. While our computers and devices on the receiving end of Wi-Fi are old enough that they can’t do more than 802.11-n, still I figured that a modern modem built to handle the potential gigabit speeds of 802.11-ac might improve throughput over that of the old Time Capsule.
To test this theory I ordered a modern modem/router, an ASUS RT-AC87R (shown below), from NewEgg. It arrived yesterday. After configuring the ASUS out of the box as a simple Wi-Fi access point broadcasting both 2.4-GhZ and 5-GhZ signals, I did a plug-replacement of the old Apple router with it.
As the figure below shows, I’m now getting a good fraction of the full gigabit when direct-wired to the ASUS, and quite respectable speeds even over 11-n Wi-Fi — about twice what the Apple Time Capsule was capable of providing at 2.4 GhZ, and twice that again at 5 GhZ. We can now enjoy 200 to 300 Mbps in day-to-day operation without the glacial slowdowns that systemically plague Comcast cable.
The next experiment to perform will be to cut the CenturyLink-supplied modem / router out of the loop entirely. The only function it is serving now is speaking PPPoE (the protocol the local CenturyLink operation, née Quest, uses to talk to fiber) in the proper form. (I have read that in other service cities CenturyLink uses the GPON or IPoE protocols for this function.)
Eliminating the redundant router will require making the ASUS speak PPPoE with the proper parameters — something for which the out-of-the-box router firmware does not have an interface. Fortunately, the ASUS can run any of the many variants of the open-source “WRT” firmware, and some recent versions thereof do let one tweak the PPPoE parameters. So I have read.
It’s possible but I think unlikely that removing CenturyLink’s router from the line of fire will offer an all-around speedup. This is, after all, the device that the company installs with gigabit service, so its electronics are probably up to the task. The one sure advantage of turning in CenturyLink’s router will be a refund of the $99 I paid them for it (in order not to be charged $12.50 a month to rent it).
The final speedup over Wi-Fi won’t come until we replace our 5-year old MacBook Pro and MacBook Air, and the 8-year-old iPad 2. New equipment that can talk 802.11-ac should provide the full gigabit, or something very close to it, over Wi-Fi. But that equipment upgrade isn’t in the cards any time soon.