A Little Off Code, Computers, Photography and Guns

Open-Source Print Server

One of the things I had always wanted to play with until I moved was a wireless router that was "deluxe" enough to have a USB port installed.

Most of the time these sorts of routers expect that you're just going to plug an external hard drive into it and pretend like it's a full-fledged NAS becuase typically they manage to squeeze CIFS into the firmware that governs the router and for the most part this is good enough for the most basic of NAS needs. Except they tend to forget that throughput with such a simple processor is usually miserable. I've never actually tested any of this myself but all of the forums I've read on the subject seem to report that there is a throughput ceiling of around 5-6MB/s which is pretty bad.

The other purpose for the USB port that I bet people would get more use out of is the ability to use your router as a simple print server. The first reason this is a lot more practical is that nearly all consumer printers these days use USB for their interface. This means that essentially any printer that can be made to work for your current computer with USB can also be put behind a print server without too much trouble. The other way this is useful is for the growing number of laptops you'll find in any given household. Except for minority of people that do enough computer work that owning a desktop is a necessity most every house will mostly be comprised of laptops and all of them will likely communicate with Wifi.

Every time you need to print something from your laptop you'll have to take it back to wherever you've parked your printer and plug it in. But you'll also need to make sure that you plug it back into the same USB port you installed it with in the first place or your computer will go into full-retard mode and "Duhhh... new printer! I'll look for drivers for your awesome new printer."

Now you see where the real hassle is. But this is the point at which a lot of people go the wrong direction. The first thought a lot of people have^[1] is that they'll just solve this problem by throwing money at it which usually means shopping for and buying a printer with network capabilities built in.

The main problem with this is that, network attached printers are expensive, quite a lot more expensive than their non-network-aware brethren. The secondary problem is that a grand majority of home networks are made possible by DHCP^[2] which divvies out IP addresses as devices connect to the network. This presents a problem when the main method for connecting to network attached printers involves knowing the printer's IP address, which can be problematic when your router arbitrarily hands out IP addresses on a regular basis. Every time the lease is up for your printer's IP address there is the possibility of that printer to get a new IP address which causes issues. So unless you are tech-savvy enough to setup static DHCP leases this will cause problems.

The next option for a lot of people is to shoehorn round peg into a square hole by buying a print server to make their current printer network friendly. See the above problem for why this isn't an optimal solution.

In comes the router with a USB port. I recently purchased a Netgear WNR3500L^[3] from newegg. If you're interested in my adventurous experience with installing Tomato on it see my previous^[4] post about that.

Now you're probably wondering how on earth a router with a USB port is any better than a print server or a network attached printer. The reason it is better is that in typical household networks the router will have the same IP address no matter how you've got DHCP configured. For the most part your router lives at 192.168.1.1 or 192.168.0.1 and this will for most situations never change.

So given a router with a USB port and proper firmware to allow for print serving you can host your printer on your router which will almost always have the same IP address and you can do this all with one device instead of having to buy a separate device.

In my situation I got lucky. I bought the router originally only intending to install dd-wrt^[5] on it. Later I found Tomato^[6] which looked like it would suit my needs a lot better than dd-wrt would. Except there was some initial stupidity on my part and eventually I got that all sorted out by installing a fork^[7] of the Tomato project which added USB support to Tomato.

For now the TomatoUSB fork only supports broadcom based routers like the original firmware but adds support for a few others which have USB ports. This is where I got lucky, I had never checked before I bought my router to see if it would be supported since I originally only intended on installing dd-wrt on it and it just happened to be supported.

Eventually I got around to unpacking my printer and decided to give it a try. While watching the USB section of the web interface of my router which at this point was running Tomato^[8]. I plugged in my printer's USB cable into my router and about 3 seconds later^[9] the printer showed up and it began serving the printer using raw data on port 9100 and with LPR^[10] queue lp0.

So that was easy... a little too easy. Lo' and behold, it was just that easy. All that was left to do was add the printer using a TCP/IP port with 192.168.1.1 as the address and use the driver that I had previously installed to use the printer via USB. That was pretty much all I had to do, it worked exactly as it was meant to the first time I tried it.

1. If they're tech-savvy enough to realize that this is possible. [↩]
2. Dynamic Host Configuration Protocol [↩]
3. Netgear WNR3500L [↩]
4. 3rd Party Router Firmware [↩]
5. http://www.dd-wrt.com/ [↩]
6. Tomato Firmware [↩]
7. http://tomatousb.org/ [↩]
8. Which has in my opinion a much more beautiful interface that dd-wrt does. [↩]
9. The default refresh time of pages that have dynamic content on Tomato. [↩]
10. Line Printer Remote [↩]