Developments in the Media and Control Networking Landscape
The world of audio networking continues to be a focal point for transformation in our industry, from piecemeal AV systems to a piece of the IT landscape. We watch these developments attentively because they foretell fundamental changes in how future AV systems will be built. Also, as Jeff Berryman, senior scientist at Bosch observed, “We seem to have a built-in desire for the next cool thing.”
As marketing workgroup chair of AVnu, the industry alliance promoting Audio Video Bridging (AVB), Lee Minich is fully confident AVB will have a central role in this transformation. Minich’s vision for AVB is one where installers build a smallto medium-sized network using AV B-capable network equipment, plug everything in, and have the AV system running with minimal IT intervention. Non- AVB ethernet devices may be connected without restriction to the same network and without fear of disturbing operation of the AV systems.
To others, the AVB promise is less focused. Jeff Berryman pointed out that not everyone sees AVB in the same light. Network engineers see it as an improvement to ethernet networking. Audio manufacturers see an interoperable standard for media transport. While those not fully briefed on the technicalities may see it as an “all-singing, all-dancing solution to networking.”
To be sure, there is excitement about AVB, but Rich Zwiebel at QSC believes, “The next big thing is interoperability. That’s the part of the AVB message people are excited about. It is not clear yet what level of interoperability AVB will actually deliver.”
Newcomer ALC Networks (a Lawo company) is creating excitement within the European broadcast industry with its RAVENNA audio networking technology. Promotional materials for the RAVENNA introduction last year at the IBC broadcasters’ convention in Amsterdam asked, “Will RAVENNA be the next big thing?” The announcement created huge excitement according to Andreas Hildebrand, senior product manager with ALC, who believes the excitement is due to RAVENNA being an open standard with no licensing fee and multiple parties participating in development.
Lee Ellison, CEO of Audinate, is more focused on the current capabilities of AVB, recognizing that, “The AVB standard offers promises of interoperability and traffic shaping for AV networks. However one must recognize that the AVB standards, like other standards, are not complete solutions in and of themselves.” Audinate has charted a technology migration path that combines current Dante offering with AVB technology to produce a complete solution.
Even if it lives up to Minich’s promise, AVB adoption may be slowed by the fact that using AVB requires using AVB-capable ethernet equipment. Such equipment is not yet widely available and is not yet well understood by some of the IT professionals that will be involved in specifying and supporting it.
Other media network protocols avoid this issue by using existing IP protocols over existing network equipment. Livewire has been available from Telos/Axia for use in local and long-distance broadcast installations since 2003. Dante has been with us since 2006 and is now both a mature and evolving IP-based solution. Q-LAN, an integral piece of QSC’s Q-Sys platform, which debuted in 2008, has been proven on enterprise-scale “converged” IP networks. RAVENNA continues to add new partners and build excitement.
Attempting to tie all this together is a new standards effort called X192, initiated in late 2010 at the AES Convention. The effort seeks to combine the best ideas of these existing and emerging audio protocols, ongoing EBU audio networking standards efforts, AVB ethernet improvements, and other existing standards from the data communications industry to define an IT-friendly interoperability mode through which these similar but incompatible systems can be tied together.
According to Zwiebel, whose employer, QSC, along with Telos/Axia, is sponsoring the effort, X192 is not a marketing contraption—it is an engineering project. “It is not trying to make money for anyone. It is not trying to be the next big thing. It is trying to create interoperability.”
Because network economics give a leg up to systems with a large installed base, existing networks cannot be discounted. By most accounts, CobraNet, developed back in 1996, is still the market leader. Jeff Koftinoff, software conductor at Meyer Sound, pointed out that any new network system or AVB implementation needs to be at least as functional as CobraNet. Given advancement in basic technology in the past 15 years, this is not technically difficult. However, It may be difficult to match CobraNet’s maturity and the number of products and professionals still supporting it.
For some, the promise of networking in AV systems is unfulfilled until control and monitoring functions are also handled in an interoperable manner. Here again we find several efforts, current and historic, vying to accomplish this. The newest is called Open Control Alliance (OCA), which Berryman, who leads technical development for the initiative, described as a continuation of efforts from the 1990s known as AES24.
In order to better your chances at success in a complex systems install, conventional wisdom encourages you to minimize integration headaches by sourcing system components from one vendor. While this may have the advantage that there’s a single someone to point the finger at if things don’t work, it creates a lock-in situation with potentially higher prices and overall functionality that is not all that it could be if one were allowed to pick and choose system components from different vendors with confidence that they would work together.
Although it is clear that a common protocol such as OCA makes true interoperability and peer-to-peer communications possible, there is disagreement as to the importance of this. Frank Vernon, an engineer at Peavey Electronics, argued that a requirement for peer-to-peer communications are rare in these systems and there’s usually a way to accomplish the intended functionality in other ways. But Berryman believes OCA will allow integrators to build subsystems and combine them to create a scalable and robust system using components from different manufacturers.
Kevin Gross (Kevin.Gross@AVAnw.com) was the primary inventor of CobraNet. He is now an independent media network consultant and the leader of the task group working on the X192 media networking interoperability initiative.