I retired my old router a few days ago. (I might’ve cried.) For the past few years my router has been a computer powered by a 900MHz Celeron CPU (512MB RAM, 2x gigabit PCI-X NIC, 2x 100MBit NIC). And it worked great. It used a Compact Flash card as its hard drive via a CF->IDE adapter and could push 300MBit/s across any two interfaces; it used CentOS 6 and packages like dnsmasq to provide various services on the network: dhcp/dhcp6, dns, ntp, etc. I had built the router as a project to learn about Linux and networking, and I had chosen that old computer because it had a serial port for a 28.8k modem.

The problem was, it used a lot of electricity for what it did; my Kill-A-Watt meter reported about 45W idle and 65W when under full load, compared to 5W-10W for modern routers. So I found a Cisco-Linksys WRT160Nv3 router for $5 at a thrift store and slapped OpenWRT on it.

The WRT160Nv3 is at least mostly supported by OpenWRT; I built my own custom image for it as I did for the RouterBoard RB411 awhile back. I’m not confident that the BCM4716B0 Wireless N radio is fully supported; there are several drivers for Broadcom chipsets and since I only needed G speeds (for a guest network), I selected the open-source b43 wireless firmware instead of the proprietary Broadcom wireless driver, out of principle. The Broadcom driver likely supports N speeds. There is a third driver (brcm80211) but I didn’t test it; you might have more luck than I did. You can switch between all of these drivers in the OpenWRT menuconfig system.

I also added some goodies to the image: iftop, tcpdump, and LuCI, the OpenWRT web UI, because it has totally spoiled me rotten. Adding them to the image instead of as modules saves space, which is important because this router has only 4MB flash. I shaved off space by disabling kernel debug symbols and removing a few other things, including opkg and ppp support.

Flashing was a minor challenge because the bootloader’s handling of TFTP flashing is broken. (This makes bricking a little easier, so be careful!) If flashing the OpenWRT from the stock web UI doesn’t work, flashing DD-WRT onto the device and then flashing OpenWRT via DD-WRT’s UI will.

After installing, I set up each port on its own VLAN, one for each subnet, and configured each one so the device would be a drop-in replacement for the Celeron box. It took a day or so of tweaking but I’m finally happy with the configuration. I even have a spare port to spin up whenever I want, although currently it’s disabled.

So how well does it work?

The wireless connection is stable; I can push 16-20Mbit/s through it without issues, which is decent for Wireless G. The device can push about 50-60Mbit/s tops between interfaces before its little 300MHz CPU gets saturated. Considering that my Internet connection is 10Mbit/s max, and the things the other ports are connected to top out about 40-50Mbit/s, it works out. For the price and the amount of electricity the device uses, I couldn’t be happier.

There’s two caveats.

One: whoever designed the case probably didn’t take a course on thermodynamics. There are actual vents, which is nice (two of my older routers have nothing more than tiny slots), but they’re around the edge of this plastic dome that collects heat at the top. Ooops! Wishing I had my Dremel tool still. It hasn’t overheated yet, but just in case I raised it up on two mechanical pencils to allow more airflow.

Two: it’s silent. That’s usually a good thing, except the Celeron router wasn’t; it had a single moving part (the power supply fan) that made a comforting whisper 24/7. I’ve had that sound in my ear for the past 4 years whenever I sleep. Now I have to get used to barking dogs and the garbage truck going past at 3AM–or find something else to make an equivalently soft noise. Preferably a something that doesn’t draw 45W power constantly!