SmallNetBuilder

At a glance
Product	NETGEAR WNR3500L Rangemax Wireless-N Gigabit Router with USB   [Website]
Summary	Broadcom-based 2T2R single band 802.11n router w/ gigabit WAN and LAN ports, USB drive file sharing and support for popular alternative firmware. DD-WRT brings lots more functions, but imposes a hit on routing performance and no significant wireless improvement.
Pros	• Up to 4K simultaneous sessions (more via command line) • VLAN and other "smart" switch features • Wireless AP, bridge, client modes
Cons	• 50% drop in routing performance w/ higher variation • Wireless power boost doesn't improve range • Hitting session limit locks up router

Introduction

The New To The Charts article summarized what the WNR3500L can do with NETGEAR's factory firmware. But most people will be buying the 3500L so that they can load alternative firmware. In fact, NETGEAR wants you to do that, since they pay an outfit named Capable Networks to run MyOpenRouter.com. That site hosts articles, how-tos and forums for hacking and tweaking the 3500L and NETGEAR's first "open source" router, the WGR614L.

Features

Some people load up alternative firmware on their routers because they think it improves performance. As I found in an earlier article (Can DD-WRT or Tomato Fix Bad Routing?) and as you'll see in this one, your mileage can definitely vary on this point.

But what you'll find for sure by flashing DD-WRT is lot more features. How many and which ones you get depends on the version of DD-WRT you use. Because some routers don't have enough flash and RAM to support the full smörgåsbord, DD-WRT comes in different flavors.

The superset of features for the current version is shown in the table below, lifted from the DD-WRT Wiki. The entire Wiki table includes a matrix of features vs. distros / builds.

V24_pre_sp2 K24 build features

That's a very broad range of features, including modules to add VPN, wireless hotspot, VoIP and additional wireless capabilities. For the real hardcore tweaker, there is also command line access to the Linux OS at the heart of DD-WRT.

The handiest feature from a wireless standpoint is the ability to configure the router so that it acts as a wireless client or wireless bridge in addition to the WDS-based bridging / repeating you get in the factory firmware and from many other wireless routers.

Client mode uses the router's radio as a WAN interface to connect to another wireless network. In this mode, clients will be behind the router's firewall. Client bridge mode bypasses the routing function, connecting clients directly to the same subnet as the wireless network you're connecting to. Both modes support only wired clients, since the radio is being used to connect to the remote network.

If you want to connect to another wireless network and have wireless clients connect to the router, then you need to use Repeater Bridge mode, which requires WDS on both routers.

Also useful is the ability to adjust the transmit power beyond the range allowed by the stock firmware (up to 251 mW). But, as you'll see shortly, this doesn't necessarily provide improved range or change the throughput vs. range curve.

Figure 1 provides a peek at the DD-WRT interface, which is logically organized and responds quickly. To really get a feel for everything available, you should explore the online simultation of V24 beta. An overview of the web interface is found in the DD-WRT Wiki and includes a map of the menu tree.

Figure 1: DD-WRT Wireless Basic Settings