802.11n Is Finally Fun, But Periodic Performance Plummets Are Perplexing

Continued from ‘NETGEAR’s WNHDE111: 802.11n Is Finally Fun‘…

Initial setup of the NETGEAR WNHDE111 was fairly easy, albeit not trouble-free. I could (but didn’t) direct-tether a computer to the access point and use a generic www.mywifiext.net URL (which auto-redirects by default, in the absence of a DHCP-assigned alternative IP address, to 192.168.0.240 when the unit is in access point mode and to 192.168.0.241 when the device is operating as a bridge) to connect to the WNHDE111’s built-in web server’s setup screens. Another supposed setup option, claimed available for any web browser- and optical drive-inclusive computer regardless of its operating system, was to search for and launch an index.htm file on the CD included with the unit…but I couldn’t find the file on my disc, and I’m not alone.

Alternatively, I suppose I could have ascertained the IP address DHCP-assigned to the WNHDE111 by my Apple router via perusing the router logs and looking for a MAC address match, or by leveraging a Windows system to see what new UPnP entry showed up in My Network Places. But instead, I decided to stick the installation CD in the Dell laptop and fire up the Windows-only Configuration Assistant, which worked fine. NETGEAR provides a simulation of an out-of-date version of the WNHDE111 browser interface on the company’s website, so you can sorta-see what I saw once I found the device on my LAN.

After connecting to the LAN (and via it, the WAN), the WNHDE111 auto-configured itself with a broadcast channel that didn’t interfere with the one used by my Apple router, and also immediately determined that an upgraded firmware release was available. After perhaps the fastest download-and-upgrade-and reboot cycle that I’ve ever experienced with a piece of gear, I was up and running with the latest-and-greatest (albeit 1+ year old) v1.2.7_1.0.1 firmware dated January 22, 2008. I’ve already mentioned that I changed the default SSID; I also:

• Set the 802.11n mode to 802.11n-only, at automatic 20/40 MHz channel width.
• Set the security mode to WPA-Personal, Auto (WPA or WPA2) encryption, using an AES cypher, and also overriding the default pre-shared key, and
• Overrode the default admin password, and also tweaked the NTP-determined time settings to match my time zone and Daylight Saving Time status.

SmallNetBuilder’s review reveals that the WNHDE111 contains (among other things) Atheros silicon for wired and wireless networking functions, along with a Ubicom QoS processor. Indicative of the latter reality, one of the access point configuration screens is branded with Ubicom’s WISH (Wireless LAN Intelligent Stream Handling) marketing moniker:

By default, QoS priority for both HTTP and Windows Media Center (how convenient for me!)-sourced streams is enabled.

Looking back at the bandwidth plots in part 1 of this post, you might be troubled (as I am) by the periodic bitrate dips seen in three of the four laptop-to-Media Center Extender configurations I tested. I’m not quite sure what’s going on here, as no other notable network activity was in progress at the time. The single-channel 802.11n approach exclusively relied on the Apple router, of course. The other three setups also involved a SMC 8-port GbE switch tethered to the router, since the HomePlug AV adapter, CAT5 cable running to the office, and NETGEAR WNHDE111 all connect to the SMC unit.

The HomePlug AV-inclusive configuration was the only one that didn’t exhibit substantive bandwidth inconsistency. On the other hand, its bitrate was consistently unacceptable for high-definition video transport purposes, as (barely) was the speed of the single-channel 802.11n approach. Conversely, buffering at the destination Extender seems to be sufficient-sized to counterbalance the random, brief performance dips seen with the otherwise robust 802.11n-plus-CAT5 and dual-802.11n-channel setups. In their plots, you can clearly see the performance-capping result of NETGEAR’s cost-driven decision to not include GbE-capable Ethernet transceivers in the device.

I’m not done tweaking my LAN, of course. Eventually, I’ll migrate from this second-generation Apple router to a second-generation (Marvell -> Atheros, among other things) Apple Time Capsule superset. By integrating both the NAS HDD and a secondary 802.11g transceiver-and-antenna combo, the Time Capsule will obsolete two additional components (a USB-tethered external HDD and a $20, at least a month ago, Belkin access point) that currently exist in my setup. And I confess that I’m still frustrated with the bandwidth disparity between marketing claims and reality that necessitated the LAN inclusion of a $55 access point implementing a second 802.11n channel. If you need to go this route, the WNHDE111 isn’t a bad vehicle to take you to a robust-implementation destination. But next time, NETGEAR, please consider making the gear GbE-capable, as long as doing so doesn’t clobber the price tag.