The Linksys WRT600N sets out to offer what no router to date can (updates added 31 Oct 2007): certified Draft N networking simultaneously in the 2.4 GHz and 5 GHz bands: This is a neat feat, but requires two radios to carry out, and carries with it a hefty $280 price tag. In testing, I found a number of design choices and missing features, along with a lapse in the standards certification process, that make me suggest that users wait for firmware updates before purchasing an otherwise quite capable router.
The WRT600N's closest competitor is the Buffalo Wireless-N Nfiniti Dual Band with gigabit Ethernet released in March for $250; it's not yet Draft N certified by the Wi-Fi Alliance, hence the Linksys unit's current uniqueness. (Read SmallNetBuilder's review.) Update, 31 Oct 2007: Buffalo is currently enjoined from importing its 802.11a, b, and n gear into the U.S.
The idea of offering both bands in a single router is simplicity: You can throw away old gear while preserving backwards compatibility and not sacrificing range nor throughput. Devices that can use the 5 GHz band and that you want to have running at full throttle can do so, particularly important for video streaming. This also allows you to reduce clutter, and to migrate older equipment to newer adapters as (or if) they're available instead of all at once.
The Ultra RangePlus Dual-Band Wireless-N Gigabit Router (WRT600N)--to use its unwieldy full name--uses Linksys's EasyLink Advisor, a piece of wizard software the company has been rolling out gradually across all its models. (It can be downloaded and used with certain older devices, too.) While the EasyLink Advisor does streamline setting up a new router, troubleshooting problems, and passing out a wireless security key, it was also maddeningly slow in "discovering" the router it was trying to reach, to which it was directly connected via Ethernet on a modern, fast Dell laptop running Vista. I found it unable to configure an internal Intel Wi-Fi adapter to connect to the network, despite its assurance that it could do so.
The router also offers the usual ancient Linksys interface behind the scenes via a Web browser for advanced configuration. I found for my basic purposes, the advisor didn't offer enough, and I expect that any user who finds the need for a dual-band, simultaneous 2.4/5 GHz router will also find the advisor inadequate because of specific settings they'll want to make "by hand."
The WRT600N has four 10/100/1000 Mbps Ethernet ports. The case is a sleek black, with LEDs on the front that display the status of ports, the Internet connection, and Wi-Fi security (enabled or not). It has a single USB port to accept a hard drive or flash drive.
The WRT600N succeeded in its primary goal in life: Providing access to two separate networks while shunting data over gigabit Ethernet to directly connected devices. The 2.4 and 5 GHz networks can be set with unique names and have separate security options.
In testing for throughput, I found that the WRT600N was highly inconsistent, but that's clearly due to my particular RF environment. Although my office is a mixed retail/office/residential building, and the neighborhood isn't that dense, we have some problem on channel 1 in 2.4 GHz that renders networks in that range completely unusable, regardless of vendor. A spectrum analyzer hasn't disclosed the cause.
In 5 GHz, I see some strangeness at times, too. As a result, I can't benchmark devices with confidence when I see low or erratic numbers that don't hold up to repeated tests. Conversely, when I see consistent high performance in such a difficult environment, I can rely on the robustness of the device.
In general, I was able to see speeds across 2.4 GHz and 5 GHz that should be expected from Draft N devices, but I'm declining to note them due to my test environment. Tim Higgins of SmallNetBuilder will have extensive, controlled test results in a few days which I'll link to. Update: These benchmarks are now available in Higgins's extensive review. I see that the number I saw aren't that far off from his more controlled tests.
Now on to some specific concerns.
Security. If you use the EasyLink Advisor, as Linksys expects many of its users will, you cannot choose your security key; the advisor creates a strong alphabetic-only key for you. That's great, but if you don't want to use the methods available for distributing that key to other computers, you have to type in a rather long set of characters.
The advisor can create an installation program with the key embedded that can be copied by the advisor onto a USB drive or transferred over a local network by connecting an Ethernet cable to a LAN Ethernet port. I tested the USB drive method, which exported fine but failed to install on a Windows XP SP2 system without enough explanation to troubleshoot the problem. (That system had the Linksys WPC600N dual-band card installed--the $100 one-band-at-a-time counterpart to the router--and all drivers were up to date.)
I would have liked to use Wi-Fi Protected Setup (WPS), as I now have a few computers that should be able to work with it. Unfortunately, in what appears to be a late decision in the release cycle, the WRT600N lacks WPS. There's a button on the top of the router that has a plastic laminated sticker around it labeled Reserved. I confirmed with Linksys that this release lacks WPS. It's a shame.
I wound up using the advanced configuration to set my own WPA2 passphrase--which can be set uniquely for each radio--to make it easier to add computers. That worked perfectly.
DHCP assistance. I like the DHCP Reservation system, which may not be unique to this model, but it's new to me. DHCP reservation lets you pick an IP address that remains persistent for a given device based on its MAC address, or the name that's set for the machine, and broadcast as part of the DHCP request. (On Macs, there's an option called DHCP ID, which is set separately, and can't be used for Windows machines.)
If you're trying to find the list of attached clients over DHCP, you use the DHCP Reservation button in the main Setup screen. It shows the client, and how it's connected: via the wired LAN or a wireless connection, where it shows which band it's connected via.
Picking SSIDs. Linksys made a strange decision in having their EasyLink Advisor set the same network name or SSID for both the 2.4 and 5 GHz networks. For adapters that support both bands, there's no simple way to mark which network you'd prefer to join. I found in testing that Linksys's own WPC600N dual-band PC Card joined the 2.4 GHz network, and I didn't see a way to change that behavior. I don't know of any tools in Windows or Mac OS X that let you preferentially set the band for networks that roam across bands, not just routers.
The advisor also won't let you choose an SSID which contains spaces, which is baffling. Linksys told me that this is due to legacy support issues as the advisor can handle older routers that cannot accept spaces in SSIDs. Sad that the advisor isn't smart enough to know which routers can and cannot, since spaces improve the legibility of a network name.
Again, I went into the advanced setup and entered separate names for my two networks. That worked perfectly.
Wide channels by default in 2.4 GHz. Linksys has chosen to release a router that's configured in opposition to the Wi-Fi Alliance certification standards; it's a loophole. Linksys ships the WRT600N set to use 40 MHz channels in 2.4 GHz by default, which means that when you turn the device on, you will interfere with double the number of networks that you would otherwise. The Wi-Fi Alliance Draft N standards say that the default should be 20 MHz, with manufacturers able to decide whether users can optionally enable wide channels. However, the alliance doesn't test for this (or even have a checkbox, apparently); Tim Higgins wrote about this last week. Update: Higgins writes on 31 Oct 2007 in his review of the WRT600N that he cannot observe the gateway dropping into 20 MHz channels as it should.
If the WRT600N would follow the standard procedure of not transmitting using a 40 MHz channel when there's traffic present that it would step on, among other characteristics, that would mitigate this problem. It would essentially moot the issue, as despite being set to 40 MHz, the router would never use a wide channel if the wrong conditions were in place.
There are three mechanisms in the Draft 2.0 version of 802.11n that are supposed to prevent Draft N devices in 2.4 GHz from sending data over wide channels in those routers that will support 2.4 GHz wide channels. I can't determine whether Linksys has implemented these mechanisms. It remains to be seen whether Linksys is acting as a good neighbor or an indifferent one.
In the best outlook if the WRT600N doesn't back off to 20 MHz before transmitting, adding a WRT600N is like adding two 2.4 GHz Wi-Fi networks, which happens all the time. In the worst outlook, the default Linksys choice degrades the shared commons far more than it needs to, thus making everyone's experience in your airspace somewhat worse.
Inadequate 5 GHz channel selection, but commensurate with everyone else. Linksys, like other manufacturers, supports just eight of the 23 possible 20 MHz channels in 5 GHz: the four lowest and the four highest, known as UNII-1 and UNII-3. The middle 15, UNII-2 and UNII-2 extended, aren't available. Apple made the same call.
A Linksys spokesperson explained that because the middle 15 channels require additional FCC certification, a backlog in that testing has prevented the inclusion of these channels. Devices that use UNII-2 and UNII-2 extended frequencies must detect and avoid radar that's in use on some of those bands around the U.S. as part of the compromise that opened more spectrum up in 5 GHz. Apple hinted to me in August that something was afoot, too. Some changes went into effect in July for legacy channels (UNII-2) that seems to have slowed certification down.
The Linksys router selects the optimum 5 GHz channel out of the four 40 MHz or eight 20 MHz it supports by default. But if you change the router's configuration from Auto to choose a specific channel, you are limited to just the lowest four (UNII-1). This is a bit baffling.
Conclusion. A number of choices have led to this router being harder to set up for a user that might demand two bands than it should have been. The lack of WPS makes it more difficult to secure for average users. And Linksys's specific choice to release a loopholed router under Draft N certification rules is simply baffling.
With firmware upgrades, I expect this router will shine. But I'll have to wait to see such upgrades before I could warmly recommend it.