AVB and What Else?
Aug 13, 2012 3:11 PM, By Bruce Borgerson
Forecasting the Future of Audio Networking
But is there evidence at hand for such optimism? There are, after all, significant bumps and gaps that still need to be addressed. Most notable, of course, is the fact that AVB is largely defined at Layer 2 of the TCP/IP model, which means new AVB-compliant switches are required for the network infrastructure. Interoperability of devices from different manufacturers remains a work in progress.
Czyzewski acknowledges, “AVB is ready for prime time, but there are gaps to fill. Interoperability with other products is still being worked out, and right now we only have a couple of manufacturers with AVB-compatible switches. That needs to be filled out for AVB to gain widespread acceptance.”
For Yamaha’s Steve Seable, AVB’s built-in flexibility adds complications. “Within the IEEE standards, there are appropriately variable ranges. For example, one manufacturer may choose to implement 44.1kHz sampling in their product, and another 48kHz. This creates incompatibility issues within a common format.”
Ironing out those wrinkles is the principal purpose of the AVnu Alliance certification program. “As AVnu rolls out testing procedures and offers more certifications, we will see more opportunities for designers to develop AVB systems that provide great solutions for end users,” Seable says. “Until that process is complete, there is a bit of a gap.”
In addition, we have to factor in the inherent time lag of product development along with marketing considerations on the part of manufacturers. “I suspect some manufacturers are hesitant to pre-announce AVB products prior to launch because doing so could cannibalize current product with existing proprietary solutions,” admits AVnu’s Lee Minich.
That leaves some AVnu Alliance supporters in an ambivalent position. “It’s currently a catch-22 situation,” observes Lab.gruppen’s Dalbjorn. “We will work toward having AVB-compliant products as soon as we can guarantee interoperability.”
Grumbling about the incompatibility of current proprietary protocols often overshadows the fact that these existing solutions offer proven strengths across a spectrum of applications.
“Since it’s all controlled by a single third-party company, interoperability and compatibility goes hand-in-hand with the product,” Czyzewski says. “If you buy a CobraNet chip from Cirrus Logic and another company does the same, the two products come together seamlessly. You don’t need a consortium to make that happen.”
Czyzewski notes that Biamp now offers two product lines based completely on CobraNet, with new products for the lines slated for the coming year.
Richard Zwiebel of QSC points out the advantage of a single-source solution where networking and end-point DSP are all integrated in one product from one company, as with his company’s Q-Lan network and Q-Sys product lines. “If products are designed to work together from day one, including the software, hardware, and GUI, then they will most likely perform better than products not designed together from the outset,” he maintains.
Zwiebel further notes that many interoperability concerts have been addressed with network bridges. He cites his company’s Q-Lan to CobraNet capability, and notes that most systems will offer analog connectivity for years to come, which still makes sense in a variety of equipment room scenarios.
Furthermore, since many large installed systems are operating fine with proprietary systems, further expansion using the same protocols likely would prove more cost efficient than switching over to AVB. “CobraNet won’t go away as long as it is supported,” Czyzewski says.
John McMahon of Meyer Sound, a strong and early AVB proponent, confirms that the CobraNet option for D-Mitri will remain for the foreseeable future.
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