The new D-Link RangeBooster N Dual Band Router, the DIR-628, joins a very short list of 802.11n-compliant routers that are compatible with both the 802.11n 2.4GHz mode (backwards-compatible with 802.11g and 802.11b) and the optional 5GHz mode (backwards-compatible with 802.11a):
5GHz support enables 802.11n networks to escape the channel congestion inherent in 2.4GHz networks (where only three of the 11 channels theoretically available do not overlap) and achieve faster throughput through the use of double-width (40MHz) channels.
To find out how the DIR-628 implements the 2.4GHz and 5GHz modes, and to find out what level of wired Ethernet it supports, keep reading.
...But Not Two Routers in One
The DIR-628's dual-band rivals actually feature two routers in one: they have dual radios that can transmit on the 2.4GHz and 5GHz bands at the same time, enabling you to have two separate wireless networks (one for data and one for streaming media).
By contrast, the DIR-628 uses a simpler (and less-costly) design: during setup, you select whether you want to use the 2.4GHz or 5GHz frequency. Thus, if you have dual-mode 802.11n and/or 802.11a wireless adapters (which run at 5GHz) on your network, you can run in 5GHz mode. If you have only 2.4GHz adapters (802.11n, 802.11g, or the pre-Cambrian 802.11b), choose the 2.4GHz mode.
This router gives you the ability to move from 2.4GHz to 5GHz without replacing the router, but there's no way to have a mixture of clients. If the DIR-628 is at the center of your wireless network, you must upgrade all of your clients from 2.4GHz or 5GHz at the same time. Ouch!
Fast Ethernet in a Gigabit Ethernet World
The other cost-cutting feature of the DIR-628 is its lack of Gigabit Ethernet support. Gigabit Ethernet is supported in other dual-band routers, enabling wired clients with Gigabit ports to run at top speed. And, some 2.4GHz-only 802.11n routers, such as the D-Link DIR-655 and the Linksys WRT310N include Gigabit support at only a slight price premium to the DIR-628.
Missed It by This Much!
In terms of features, the DIR-628 is a puzzling mixture of the interesting (switchable between 2.4 and 5GHz) and frustrating (runs only one band at a time; lacks Gigabit Ethernet ports). The DIR-628 is likely to be of the greatest interest to those who already have 5GHz-compliant 802.11n (or 802.11a) hardware and are looking for a low-cost way to move to 802.11n support. For the vast majority of users, however, who are running in the 2.4GHz band or have dual-band clients, there are better choices in the marketplace.