Over the past decade, audio-over-IP and more recently video-over-IP has revolutionised the way radio and TV broadcasters move their signals around. Network AV solutions are about to do the same in the audio visual industry, as IT departments realise the power and flexibility of IP distribution.
No More Central Routers
Central routers have been a mainstay of audio and video distribution systems. First they were analog. Then AES audio, SDI video and DVI/HDMI PC signals saw an array of digital routers proliferate – from small in-room rack boxes to massive card-based multi-format switchers. With their abilities to be controlled, scheduled and remotely switched, router systems opened up new possibilities and efficiency.
But their Achilles’ heel is the large amount of expensive single-purpose cable, which needs to run long distances back to central racks in equipment rooms and service cupboards. This makes them expensive to install and often very difficult to upgrade when needs change in the future.
CAT6 media converters, such as HDBaseT, have made central A/V routers more manageable, by allowing longer runs on less expensive cable. But these systems are still managed separately from the IT network, and are often inflexible.
Network AV benefits
Network AV brings audio visual services fully into the IT world. Using business-grade gigabit switches, audio and video up to 4K can easily be moved on a corporate or campus network. Signals are converted to IP using converters that are only marginally more than existing CAT6 media converters. Once in the IP realm, the audio/video streams travel as multicast groups, with encryption, security and content protection. Using multicast means the bandwidth is optimised, and streams of 950mbit/s can happily share uplinks with voice, office traffic and other applications.
Being IP-based, your organisation can design a network topology to integrate Network AV. In many cases, existing networks can add Network AV with minimal changes or upgrades.
IP distribution of media does offer unmatched flexibility. But there are a few challenges as well.
Traditionally. digital media signals like AES audio, SDI video, HDMI and even voice signals were run on dedicated serial transmission lines. These point-to-point connections had dedicated cable types, and were generally very reliable. They weren’t always trouble-free – requiring specialist test gear to commission and diagnose faults.
As IP networks become faster and wider, it makes a lot of sense to “packetise” these dedicated serial signals and move them on existing networks. This gives IT departments a single type of cables and distribution equipment to manage, and far more flexibility to reconfigure the network as organisational needs change.
Audio was pretty easy to move to IP – each stereo audio signal is only a few megabits and even a big deployment can easily fit into an existing network. Video is a little trickier. Uncompressed video signals can get as high as 12-16 megabits once 4K/UHD video is needed, and this is a big stretch for most networks. Usually, some form compression is needed to bring the overall bandwidth down, but this can add latency and quality concerns if not done properly.
Multicast IP also adds new challenges. Although the multicast protocols such as IGMP have been around for decades, their use has been relatively limited until the last 10-15 years. Multicast traffic is fairly easy to integrate into a network, but it requires switches with native support, and an understanding of multicast groups and protocols.
Not all switches will support high-bandwidth video either. Any enterprise-grade switch from HPE, Cisco, Juniper, Arista of the other big names will be fine. Even lower-grade switches such as Cisco Small Business and Netgear can work perfectly well. It is important to know what your switches are capable of – can they support uncontended backplane switching, and do they understand multicast traffic?
Crestron NVX Digital Media range
The NVX range from Crestron gives you 4K video and multi-channel audio over a multicast gigabit network. The encoding is frame-based, so very low latency (around 1-2 frames), and equivalent in quality to a native connection.
Bandwidth usage is configurable, up to 950mbit/s for highest quality or as low as 200-300mbit/s if you need to conserve bandwidth on switch uplinks to certain areas.
The content is fully encrypted through the chain, and therefore fully HDCP compliant. Switching between sources is quick and easy, and fully managed by the Crestron control system.
In a fully networked A/V system, the NVX units replace a traditional Digital Media transmitter or receiver. This can remove the need for central presentation switchers, or just provide the links between rooms and remote sources. Pricing for NVX systems is comparable to a traditional router-based matrix, and if the existing network infrastructure is already in place, may even be cheaper.
For more information on the Creston NVX range, see our iTkey media page and the Creston NVX microsite.
How iTkey can help with your Network AV migration
We’ve been building IP networks for media for a decade, so intimately understand the benefits and pitfalls of Network AV. Our qualified network engineers understand multicast inside-out, and know how to design a network with audio and video in mind.
As an IP System Integrator, we work across many disciplines, including networking, servers, lighting control, audio visual, security and CCTV. All the systems we work with are designed to be integrated into an IT network, so you have full control.
We can help with new designs for a relocation/rebuild, or help assess and upgrade your existing systems. iTkey engineering staff have recently completed the Crestron NVX training course, so we are fully certified to help with any Crestron Network AV projects.
If you are interested to learn more, we can show you our own demo room, including:
- Crestron touch-screen control and room scheduling
- Crestron NVX Network AV integrated with the 4K Digital Media Presentation System (DMPS)
- C-BUS Lighting Control
- Shure MicroFlex ceiling array microphone with DANTE Audio
- Skype for Business video conferencing
- Panasonic PTZ and fixed cameras
- CMS Electracom Soft Power
In an future post, we’ll cover more details of the recent demo room build project.
In the meantime, please visit our website for more details – itkey.com.au