The 855's feature set is the same as the 4500's with the exception of wireless configuration, which handles two radios instead of one. D-Link doesn't have an emulator up for the 855, but you can use the 4500 emulator to explore everything else in the admin interface.
Figure 5 shows the main Wireless Settings screen, which conveniently contains both 2.4 and 5 GHz radio controls. Like the 4500, the user interface does not indicate the extension channel used in 40 MHz channel mode, which I think it should.
Figure 5: Wireless configuration
The 855 continues the 4500's welcome feature of being able to enable/disable wireless on a schedule. This is nice touch to help keep your network secure during off-hours.
I thought it interesting that the 5 GHz radio defaulted to the 20 MHz channel width instead of the faster Auto 20/40, even though it didn't have to. The 2.4 GHz radio properly defaulted to 20 MHz channel width, as all Draft 2.0 802.11n Wi-Fi Certified products should.
Note that channels in the 5 GHz Lower (36, 40, 44, 48) and Upper (149, 153, 157, 161, 165) bands are available, whether or not you choose the Auto Channel Scan Wireless Channel option.
The 802.11 Mode selector provides just about all the options you would need to solve compatibility problems with "legacy" 802.11b/g clients. For 2.4 GHz you get:
- Mixed 802.11n, 802.11g and 802.11b (default)
- Mixed 802.11n and 802.11g
- Mixed 802.11n and 802.11b
- Mixed 802.11g and 802.11b
- 802.11n only
- 802.11g only
- 802.11b only
and for 5 GHz you get:
- Mixed 802.11n and 802.11a (default)
- 802.11n only
- 802.11a only
The Basic Wireless settings screen also provides access to Wireless Security settings, which include a full suite of WEP, WPA and WPA2 settings, with both "Personal" (PSK) and "Enterprise" (RADIUS) WPA/WPA2 modes. Security can, of course, be set separately for each radio.
I did a quick WPS pushbutton session check with D-Link's DWA-160 Xtreme N Dual Band USB Adapter—D-Link's only dual-band adapter. I carefully reset the router to defaults, which is important to get a good initial security setup (see Wi-Fi Protected Setup (WPS) Need To Know).
I was able to get a Push-button WPS session to successfully complete with a WPA/TKIP secured connection to the 2.4GHz radio, even though both router and client support WPA2 / AES. I tried to get a WPS connection to the 5 GHz radio, but was unsuccessful. This could be due to the fact that both radios are set to the same SSID ("dlink" plus the last four LAN / WLAN MAC address characters).
Figure 6 shows the Advanced Wireless controls, which are no different from the 4500's. The WLAN partition only prevents wireless client-to-client communication. Unfortunately, there is no control to prevent wireless clients from communicating with wired LAN clients, as I found on D-Link's DAP-1522 [reviewed].