On the Inside
The 685's 2x2 draft 802.11n radio uses a Ralink RT2880F 2T3R MAC/BB and RT2850L 2.4/5 GHz 2T3R transceiver. Though the radio is capable of dual-band operation, it is locked to single-band 2.4 GHz operation. The DIR-685 has 64 MB of RAM and 32 MB of flash. Figure 5 shows the internal layout of the DIR-685.
Figure 5: Internal Layout of the DIR-685
The WAN port and four LAN ports are handled by a Realtek RTL8366 Gigabit switch that appears to have support for jumbo frames up to 9K enabled. There is also a small, extremely loud fan that ran constantly during throughput and NAS testing. It sits at the top right of the case, in line with the radio and processor.
The processor could not be determined due to a soldered-in radio module over an RF shield. It does not appear Ubicom-based, however, since Ubicom's signature automatic QoS features are not present in the 685. It does, however, support simpler QoS as shown in Figure 6.
Figure 6: QsS Engine
Other D-Link routers automatically measure the uplink speed of your Internet connection to properly set QoS parameters. But you have to enter what you believe (or have tested) your Internet performance to be on the 685.
The 685's setup is quite similar to other D-Link routers'. An adhesive label pasted across the ports on the rear of the router (that did not peel off cleanly) warns you to run the installation CD first. Of course, if you have a Mac, you’re out of luck – the wizard is only PC-Based. D-Link does, however, provide a large 28” X 15” setup poster that will guide you through a basic installation – regardless of what type of computer you’re using.
The PC-based wizard gives you the option of using the DIR-685 as a replacement router, or to use it in addition to your existing router. I chose the second option, since I planned to test the router “behind” my existing DIR-655. The wizard guides you through all of the steps required to set up your router, including unplugging and plugging in cables.
Since I have installed dozens of routers, I skipped ahead and made all of the wiring changes required before running the wizard. That turned out to be a mistake, as the wizard thought that my Ethernet cable was disconnected – even though it was connected and had already gotten an IP address from the 685. I disconnected everything and re-ran the wizard, carefully following each step without jumping ahead, and the wizard did completely configure the router – including setting up the wireless network security and administrator password.
It’s worth noting that the wizard instructs you to plug in your cables based on color-coded ports – blue for LAN and gray for Internet. Though it may be limited to the first production run of the 685, none of the ports on my review unit were color coded like other D-Link products I’ve reviewed. The ports were identified, however, with numbers and “WAN” molded into the plastic and a small label on the rear panel.
My recommendation would be that if you’re tech-savvy enough to connect your modem and computer to the WAN and LAN ports, go ahead and do so and skip the "wizard". After rebooting your modem and router, point the browser on the computer connected to the LAN port to http://192.168.0.1. It will save you a lot of time. A wizard in the router runs the first time you connect to it.