The Open Source WRT54G Story Feature-Packed Open Source Firmware Upgrades Aaron Weiss
The story of the Linksys Wireless-G Router (model WRT54G) and how you can turn a $60 router into a $600 router is a little bit CSI and a little bit Freaks & Geeks. It’s also the story of how the open source movement can produce a win-win scenario for both consumers and commercial vendors.
What’s especially exciting is that tricking out this router doesn’t require any eBay sleuthing or other hunt for some off-the-wall piece of hardware. Instead, grab it off-the-shelf. The WRT54G is stacked high in every Best Buy and Circuit City across the country and, of course, most online retailers — Amazon.com, for example, sells it for $55. It’s ubiquitous and, some would say, a diamond in the rough. Or a wolf in sheep’s clothing.
While routers used to be the domain of networking specialists, they’ve gone mainstream along with residential broadband. Commodity routers can be had for as little as – well, "free after rebate" in some cases, and often not much more. To keep them cheap, consumer-grade vendors like Linksys repackage designs from OEM vendors rather than design the hardware and software in-house.
The tradeoff for these sub-$100 routers can be reliability, particularly in the coding of the firmware — the software “brain” that controls the router’s functions. Consumer-grade firmware may be buggy, and may be limited in functionality compared to commercial-grade routers designed for business such as those made by Cisco and SonicWall.
The WRT54G was released in 2003 in anticipation of the 802.11g standard, with its theoretical maximum bandwidth of 54Mbps compared to 802.11b’s 11Mbps. In many respects the WRT54G is a typical wireless router — it accepts an incoming broadband link such as cable or DSL and shares it between its built-in four-port Ethernet switch and antennae for broadcasting the signal to wireless clients.
In June 2003 some folks on the Linux Kernel Mailing List sniffed around the WRT54G and found that its firmware was based on Linux components. Because Linux is released under the GNU General Public License, or GPL, the terms of the license obliged Linksys to make available the source code to the WRT54G firmware. As most router firmware is proprietary code, vendors have no such obligation.
It remains unclear whether Linksys was aware of the WRT54G’s Linux lineage, and its associated source requirements, at the time they released the router. But ultimately, under outside pressure to deliver on their legal obligation under the GPL, Linksys open sourced the WRT54G firmware in July 2003.
With the code in hand, developers learned exactly how to talk to the hardware inside and how to code any features the hardware could support. It has spawned a handful of open source firmware projects for the WRT54G that extend its capabilities and reliability far beyond what is expected from a cheap consumer-grade router.
Feature-Packed Firmwares
So the Linksys WRT54G can be loaded with replacement firmware that delivers exciting new features — which raises the question – like what?
To start, you can expect most replacement firmware to support the same basic functions Linksys provides out of the box for this wireless router. Often these features will be more stable, in cases where Linksys’ bugs have been fixed by other developers. But that’s not what makes open source firmware so exciting.
The real deal is what the WRT54G can do, with the right replacement firmware, that you’d only expect to find on a commercial-grade router costing several times as much.
You could use the WRT54G as a repeater or a bridge. Create a wireless distribution system (WDS) or a mesh network. Run a VPN server. Or a VoIP server. Or a managed hotspot with a RADIUS server. Manage bandwidth use per protocol. Control traffic shaping. Support IPv6. Boost antenna power. Remotely access router logs. Operate the router as a miniature low-power PC, running a variety of Linux applications.
That’s just the short list. Some firmware offerings support a wide range of these features while others are more tailored to specific router applications. Some sport friendlier configuration interfaces while some are command-line driven. But most importantly, because these firmware files descend from Linksys’ open-source progenitor, they are freely available.
The key caveat, of course, is that Linksys will not support alternative firmware — only their own official version. Should you run into a problem with replacement firmware, or wind up disabling your router (which is rare but possible – stay tuned), you’ll be on your own. If you already own a WRT54G and it performs just the way you need it to, mucking around with replacement firmware might just break something that didn’t need fixing.
On the other hand, if adding enterprise features to a $60 router sounds worth the minimal risk, you don’t need any special hacker skills to get there. If you’ve already set up an off-the-shelf router before, replacing the WRT54G’s stock firmware with a feature-laden substitute is well within reach.
