Brian's Brain

By upgrading my HomePlug AV adapters to second-generation silicon coupled with newer firmware, along with updating my router to a newer 802.11n-compliant version, I'd hoped to subsequently be able to stream audio to my Apple TV in a trouble- and workaround-free fashion. And indeed I'm able to share the happy news with you that iTunes now handles my HomePlug AV-connected Apple TV as a Remote Speaker set...that is, when it can find the Apple TV. Another random issue has cropped up since my migration to the newer powerline networking adapters and router; sometimes (but, of course, not always) my computers are not able to find the Apple TV on the LAN, even though the router sees them all (as judged by their common ability to access Internet resources).

That's not the only (again, random) problem I'm having with this new hardware setup. Sometimes, the Xbox 360s acting as Media Center Extenders aren't able to find my Dell laptop running Windows Vista Ultimate...while other times they can locate the XPS M1330's Media Center server but connection attempts fail. The solution for both this and the Apple TV issue is maddeningly similar:

• Unplug and replug HomePlug AV adapters at the server, at the client and/or at the intermediary router. This 'reboot' usually restores connectivity, but sometimes I also need to...
• Manually un-pair and then re-pair the associated server (iTunes or Media Center) and client (Apple TV or Media Center Extender)

This common behavior across divergent pieces of hardware and associated operating systems further supports my longstanding suspicion that HomePlug AV is having issues with some nuance of the User Datagram Protocol. As such, last weekend I decided to revisit DS2's competitive UPA technology, which I hadn't evaluated in over a year. I still had the three NETGEAR HDX-101 adapters in-hand, which I supplemented with three more units purchased from Ebay. DS2 also supplied me with four of the newer NETGEAR HDX-111 units, along with two DS2 reference design adapters, all based on second-generation UPA silicon.

As review before sharing my DS2 results, above is the two-week-old snapshot of the HomePlug AV adapter topology, with Device 1 connected to the Windows Vista Ultimate-based Dell XPS M1330:

• Device 2: connected to two Apple Power Macs in my office on the other side of the house, via a GbE multiport switch
• Device 3: connected to the router in the middle of the dwelling, via a GbE multiport switch
• Device 4: connected to a home theater stack (Xbox 360, PlayStation 3, Apple TV) in the living room via a 10/100 Mbit multiport switch
• Device 5: connected to a Universal Devices INSTEON-based home automation controller (yes, that's right...powerline-based home automation, linked to the router via powerline networking), and
• Device 6: connected to a home theater stack (Xbox 360, Roku Netflix Player) in the bedroom via a 10/100 Mbit multiport switch

Above are the results with the first-generation DS2 silicon-based NETGEAR HDX-101s, which had identical firmware versions and QoS (UDP High Priority) settings, after unplugging all of the HomePlug AV adapters and replacing them with UPA alternatives in the exact same plug locations:

• Device 1: Dell XPS M1330
• Device 2: Office
• Device 3: Living room home theater stack
• Device 4: Home automation controller
• Device 5: Bedroom home theater stack
• Device 6: Router

Alas, although the reported bandwidth (in both directions, in this case) between the Dell laptop, router and living room-located Xbox 360 was supposedly robust, and although all of the gear reliably 'saw' each other in my admittedly limited testing, bitrate reality far undershot the high expectations set by NETGEAR's configuration utility. When the Xbox 360 was even able to connect to the laptop, which was only occasionally, the Media Extender user interface was incredibly sluggish and streamed television content was unacceptably artifact-filled and frame rate-deficient. Running the Media Center Network Performance Monitor clued me in to why: measured bandwidth far undershot what Microsoft judged acceptable for standard-definition television, not to mention HDTV.

Next, I replaced the HDX-101s with the adapters based on second-generation DS2 silicon. Above is the report from NETGEAR's HDX-101 configuration utility...

...and, after installing the HDX-111 utility, the above is what it had to say (asterisk'd units were the two DS2 reference adapters):

• Device 1 (and Device 7, in the HDX-101 report): Dell XPS M1330
• Device 2 (and Device 12): Office*
• Device 3 (and Device 11): Router*
• Device 4 (and Device 10): Home automation controller
• Device 5 (and Device 9): Bedroom home theater stack
• Device 6 (and Device 8): Living room home theater stack

Note from the reports that the two DS2 reference design adapters contained newer firmware than that in the NETGEAR HDX-111s. Unfortunately, I didn't have access to a firmware image file that I could use to 'flash' the HDX-111s to the same version; v4.4.9 is the latest available for download from NETGEAR's website. And alas, once again even though the configuration utilities reported reasonably robust connectivity between the Dell laptop-based Media Center server and Xbox 360-implemented Media Center Extender, real-life bandwidth was as poor as that I'd seen with the first-generation HDX-101 units.

I daresay that hit-and-miss (but fixeable) discovery followed by robust bandwidth handily beats seemingly robust discovery followed by consistent-miss bandwidth in my mind, so for now I'll be sticking with these HomePlug AV units. I'll report my findings back to DS2, along with an invitation to head up to my home office for live debugging (accompanied by a reminder to also pack snow skis in order to further justify the lengthy roundtrip commute from Silicon Valley). If DS2 takes me up on my offer, and if our experimentation cultivates more positive results, I'll publish an update here on Brian's Brain.

p.s...Here's the truly ironic bit. Recall that this latest set of experiments was instigated by my inability to stream audio from iTunes to Apple TV over a powerline networking spur. Now, recall that I've subsequently migrated to an 802.11n-supportive Apple router...and that my Apple TV is also 802.11n-cognizant. Yep, you guessed it...I've decided to ditch powerline networking for the Apple TV (but not for the rest of my living room home theater stack, which is still stuck at the lower bandwidth 802.11g prior generation) and go with Wi-Fi instead. Sigh.