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AoIP, AES67 and Interoperability

Audio-over-IP networking systems have largely been unable to play together nicely—until now.

Audio-over-IP networking systems have largely been unable to play together nicely—until now. In September 2013, the Audio Engineering Society published AES67, a standard for high-performance streaming over audio-over-IP interoperability, which has already been implemented by Telos Alliance’s Axia division and ALC NetworX, the organization behind RAVENNA.

“We had this 10 years ago with VOIP with the telephone guys and the network guys,” observed Roger Charlesworth, executive director of the DTV Audio Group, addressing that potential culture clash during his organization’s annual NAB meeting. “They both had to realize they served the organization—but it was a big management problem.”

According to Felix Krückels, business development director, Lawo, “I’m pretty sure an audio engineer won’t be an IT guy in the future. It’s the same for the IT guy; he won’t be an audio engineer.” Offering Lawo’s commentary equipment implementation at the 2014 FIFA World Cup Brazil as an example, Krückels noted that once the network is configured, the audio engineer’s job will be the same as pre-AoIP days. But instead of physical patching, software now handles routing management.

Patrick Warrington, technical director for Calrec Audio, which recently announced its adoption of AES67-compliant RAVENNA, is not concerned about large enterprises. “It’s the smaller organizations where maybe they don’t have full-time IT departments. Are they going to be able to install an infrastructure and know enough to be able to make it cope with perhaps unpredictable demands?”

But as Greg Shay, chief science officer for Telos Alliance, pointed out, there is already an experienced, established AoIP user base. “Even though AES67 is relatively new, just coming out this year, it’s important to realize that it’s based on the same audio-over-IP techniques that, for instance, we’ve been using in the radio industry with Livewire [Axia’s network system] for over 10 years. We’re up over 6,000 studios, live on the air. So don’t think for a minute that AES67 is somehow new or inherently not proven.”

“One of the requirements was that this works through standard Ethernet switches that you can buy,” commented Kevin Gross, X192 (the AES task group that developed AES67) committee chairman, independent engineering consultant and inventor of CobraNet. “We could have invented something new that worked through standard switches, but we also wanted to use the standard protocols.”

As noted by Lee Ellison, CEO of Audinate, by incorporating existing standards into AES67, the X192 working group instinctively fell into line with MIT professor John Sowa’s Law of Standards. “It says whenever an organization develops a new standard from scratch, the end result is that they have to go back and simplify using existing standards,” said Ellison.

Axia also took a standards-based path, said Shay. “It really goes back to the choices we made with Livewire over 10 years ago to pick standards, just like we did for AES67; we landed on a lot of the same things. It was an advantage of being part of [X192] that we were able to participate and not have it end up being too radically divergent.”

AES67 certainly appears to have plenty of momentum. “We’ve seen this standard become ratified in pretty much lightning speed by AES standards. It took two years—unheard of!” said Warrington.

In February, Audinate announced plans to offer AES67 support in Dante “within 12 months.” Then, in March, QSC Audio announced that the latest Q-Sys network audio platform software release meets AES67 network clock and audio packet delivery standards and that all future Q-Sys software releases will be fully compliant with AES67.

“I don’t think the challenges of interoperability are that great,” said Ellison. “For us to do firmware updates of FPGAs is pretty straightforward.”

For audio equipment manufacturers the ability to easily interconnect and communicate with other manufacturers’ products, versus existing within a silo, makes sound business sense. Said Shay, “We had to decide what is more valuable to us in the long term—to be a part of the greater whole or to have this carved-out niche. We knew that the greater value was to be interoperable.”

Audinate, by signing up over 140 Dante licensees, has helped lead the audio industry’s adoption of AoIP.

Audinate believes in Metcalfe’s Law, said Ellison. Also known as the network effect, it states that a network’s value is proportional to the square of the number of nodes on the network; the more users there are, the more valuable the device becomes to each owner. “By adding AES67, we will be able to connect with a larger eco-system. We think that makes the market bigger.”

There is still work to be done, observed Krückels. AES67 may enable devices to connect, “But it doesn’t give us the usability for the operator in day-to-day work. We now have to have a management software.”

But fundamentally, and most importantly, “What use is an interoperability standard if you don’t have lots of products to interoperate with?” asked Warrington. “So you need to have a lot of companies signing up for this.”