AJA Video Systems has joined the RAVENNA community, a network of partners devoted to advancing the RAVENNA standard for distributing real-time audio over internet protocol (AoIP).

AJA’s DANTE-12GAM and OG-DANTE-12GAM audio embedder/disembedder products support RAVENNA. The products make it easy to bridge between SDI and AoIP infrastructures. Both include dual 12G-SDI input and outputs, providing up to 32 channels of audio embedding and 32 channels of disembedding simultaneously for a total I/O capacity of 64 channels.

“As the transition to IP accelerates, interoperability is essential for our customers, many of whom are working with a combination of SDI and IP tools,” AJA President Nick Rashby said. “Joining the RAVENNA community underscores our ongoing commitment to meet customers where they are in their IP journey, broadening AJA product support for the larger AoIP ecosystem. RAVENNA is a powerful AoIP option, and now our customers can take advantage of it.”

Welcoming the company to the RAVENNA community, Lawo RAVENNA Evangelist Andreas Hildebrand said RAVENNA support in select AJA products will “unlock seamless interoperability with a range of AoIP protocols—and that benefits all professionals looking to make the most out of AoIP.”

More information is available on the AJA Video Systems and RAVENNA websites.

At this year’s NAB Show, I was engaged in a discussion about audio over IP with Phil Wagner, recently named president of Apogee, when he mentioned that no one was really discussing how to merge the technology into existing television environments. My own columns have been pointed more toward implementing it into new builds.

THINGS TO KEEP IN MIND

There are really just a few key things to keep in mind when tossing AoIP equipment into the technology mix of a current broadcast plant, but with SMPTE ST-2110-based facilities coming online and AoIP beginning to manifest itself in a very physical sense, this seems like a good time to look at them.

Just as we’ve done since television audio became digital, everything in the plant needs to be referenced to the same master clock. This has traditionally meant providing either black, tri-level, word clock or AES reference (DARS), but network connected devices—surprise—look for their clock on the network, which means we now need to provide them with an IEEE 1588 Precision Time Protocol (PTP) clock, which has been referenced to the house master. In the past this might have been achieved with a master clock from the IT world, but broadcast device manufacturers now provide master sync generators that include PTP alongside standard reference signals. Reference remains critical because the audio going through those network cables is still digital, so nasty tics, pops or complete lack of audio is the result when the reference clock is missing or incorrect.

Choosing a specific AoIP technology can seem like a daunting task since incompatibilities remain even with the publication of the AES67 standard. Remember that AES67 is not an end-to-end solution but is a defined set of internet protocols that, if followed, will allow audio to pass from one AoIP device to another. The good news is that virtually all AoIP equipment manufacturers ship their newer products with an AES67 compatibility mode of some sort, which ensures that audio will pass when connecting a box with one AoIP technology to a box with a different AoIP technology.

The bad news is that the audio is all that is guaranteed. Sticking with a given AoIP technology, Dante, LiveWire, Ravenna or WheatNet for instance, provide a more end-to-end solution so that all AoIP equipment on the network is aware of each other and information can be shared between them. It also means having full control of those devices, allowing routing and management. Mixing AoIP technologies doesn’t preclude the possibility of doing any of these things, but the lack of information sharing between technologies can make it very, very difficult.

OPERATING IN AES67 MODE

Careful planning is the best course of action before heading down the AoIP road. Since AES67 is the PCM audio transport of ST-2110, any AoIP devices in the broadcast chain will most likely need to operate in AES67 mode, so it is necessary to determine what, if any, features are lost when switching devices to this mode. Since discovery, control and management are not part of AES67, it is also critical to determine how this will be done prior to adding AoIP devices to the plant.

As previously mentioned, sticking with one technology or manufacturer will solve this problem, but this may not provide all the necessary pieces. There are now some third-party software products that promise to make differing AoIP solutions work together despite their differences, but a demonstration of the software controlling actual hardware seems in order before committing to this.

A solid solution seems on the very near horizon however, and it is already part of the ST-2110 package of standards. Obviously, ST-2110 will need discovery and registration, connection management and control, so the Advanced Media Workflow Association (AMWA) Network Media Open Specifications (NMOS) IS-04 and IS-05 have been chosen to solve those needs for ST-2110 devices. This means that AoIP devices in television facilities will use AES67 for audio transport, IS-04 to locate each other, and IS-05 to connect. Actual implementation of these specifications will be through additional software, but this is the current solution planned for SMPTE ST-2110.

A temporary workaround to the lack of discovery, connection and control across all AoIP technologies is to build an AoIP system from a single technology, then isolate this AoIP island from the rest of the plant with the exception of converting signals going in and out of these rooms. This could work for an audio suite (or group of suites) or even live mix rooms where IO to the room is self-contained and does not need to interface with other IO other than for ingest and playout. Outfitting professional broadcast audio consoles (and some semi-pro models) with AoIP alongside SDI, MADI, AES, analog IO as part of the system’s configuration is becoming standard practice. Achieving the same thing in video edit suites and the greater facility will prove a bit more difficult, and will involve more interstitial pieces. But again, advance planning is key, and part of that planning should be looking toward the facility’s future and not just its current state.

Probably the easiest part of adding AoIP devices to a television facility is connecting existing audio and networked audio devices together. There is more to it than just plugging in Ethernet cables for the AoIP devices themselves, since they need to be set up properly on the network. The type of network and its particular setup will determine how complex this actually is. Yet when it comes to interfacing AoIP devices with traditional audio devices there are plenty of solutions available of all types.

Attention needs to be paid to the underlying technology and whether it has an AES67 mode, but not every piece will be part of the broadcast chain.

Jay Yeary is a television engineer who specializes in audio. He can be contacted throughTV Technologymagazine.

WESTFORD, MASS.—Artel Video Systems has signed on as a partner with Ravenna, a technology platform that serves as a real-time media IP network environment.

ARG Quarra PTP

Artel Vice President of Product Management Rafael Fonseca said that the company’s ARG Quarra PTP switches were specifically designed to work with Ravenna. “In support of other AES67 devices, the ARG Quarra offers switch solutions to end users who are investing in IP media networks and who favor Ravenna technology for implementing AES67,” Fonseca said.

Artel is a provider of multimedia delivery systems.

LAS VEGAS—Ravenna was all about IP at the 2017 NAB Show, hosting an IP Showcase that demonstrated full IP interoperability based on ST2110 and that was supported by a number of organizations, including AES, AIMS, AMWA, EBU, IABM, MNA, SMPTE and VSF.

The demonstration featured an audio section that included 15 Ravenna-based devices, all of which were fully interoperable with other AES67/ST2110 gear from various manufacturers. Part of the demo saw a Lawo console receive more than 20 audio streams generated by Ravenna/AES67 devices and video equipment from Grass Valley, Imagine and Panasonic. There were also examples of timing and synchronization (ST2059) and on ST2022-7 redundancy and NMOS IS04 discovery and registration.

The Ravenna booth also highlighted ST2110 and AES67 interoperability, like interoperability with a Dante-based TF-1 console from Yamaha. Attendees got to see stream redundancy between two Lawo A_Line analog-to-IP interfaces built on ALC NetworX’s COMi.MX 2x64ch Ravenna SoM boards.

Ravenna is planning on having similar presentations at the upcoming AES show in Berlin and the Network Technology Seminar hosted by the EBU.

MUNICH—Class was in session for those in attendance at the Genelec Experience Centre in London, as Ravenna and Genelec teamed up to host an educational event of AES67.

“Everything You Wanted to Know About AES67 But Were Afraid to Ask” began with an introduction from Roland Hemming of RH Consulting, who provided an overview of audio networking, adoption levels across the industry, and examples of projects that rely on audio networking. Then ALC NetworX’s Andreas Hildebrand led the class by explaining the specifics of AES67, how it works and how it impacts the industry’s increasingly connected environment.

After that, Hildebrand offered a live demo of an AES67 system using a Cymatic Audio uTrack24 multitrack recorder/player, an ARG switch, a Grandmaster clock from Sonifex, a Ravenna Virtual soundcard, and Genelec 8430 IP speakers. Later, a Dante device was added to the setup to show streams running back and forth between the Ravenna and Dante eco system.

Hildebrand said after the event that it is likely that Ravenna will host similar events in the future, though no details are available at this time.

MUNICH—The Ravenna community is welcoming another member, as ALC NetworX has announced that Audio Video Technologies (AVT) will contribute to the development of Ravenna/AES67-enabled products.

AVT is a manufacturer of telephone hybrids or talk show systems, which are used to convert incoming phone calls into an audio signal that is suitable for a studio environment. The company also deals with audio codecs for audio transmissions over different networks.

“The move to implement Ravenna into our new products represents another milestone toward open standards,” said Wolfgang Peters, AVT’s sales director.

MUNICH—Broadcast equipment manufacturer TSL Products has announced that it is now a part of the Ravenna Partnership Community. The company showed its first products to be compatible with Ravenna technology at the 2016 NAB Show—the Monitor Plus Audio range of monitoring products.

Ravenna is a technology for real-time distribution of audio and other media content in IP-based network environments. The technology is designed to meet the requirements of the pro audio market featuring low latency, full signal transparency and high reliability. Ravenna is fully compatible with the AES67-2013 standard.

TSL’s MPA products are now available in a version with integrated Ravenna connectivity.

“The move to integrating Ravenna was a logical step in order to remain in sync with the industry’s rapid move to AoIP workflows,” said Matt Colman, product manager, TSL Products.

MUNICH & TORONTO—Ward-Beck Systems, a Toronto-based provider of broadcast equipment, has announced that it has added Ravenna/AES67 connectivity to some of its products. Among the company’s set of products that now come with Ravenna/AES67 connectivity include the AMS2-N two-channel monitor, AMS8-N eight channel monitor, 32ME-N dual 16 channel network converter with metering, and MLC8-N eight channel converter with metering and level control.

Ravenna is a technology for real-time distribution of audio and other media content in an IP-based network. The Ravenna technology was developed by Munich-based R&D company ALC NetworX.

Ward-Beck joins a group of other companies that are part of what ALC NetworX calls the Ravenna community. Other members include 2wcom, Calrec, GatesAir, Lawo, Linear Acoustic, Riedel, Sennheiser and more.