Over the past ten years, in particular, IP-based networking has become a default standard in pro AV as well as in broadcast. Thanks to technologies such as Dante, NDI and the ST 2110 standards suite, there are now plenty of tried-and-trusted approaches to moving audio, video and data over IP.
But despite these obvious advances, there has been a continued suggestion for some time that we might still be missing one or two pieces of the puzzle. In particular, end-users and integrators have wondered how best to control, monitor and manage IP networks so that they are secure, flexible, and as conducive as possible to stress-free operation.
Fortunately, there are several major initiatives – some already having recent fruition – that address these issues and, in effect, promise to close the circle for even then most demanding of IP-based operations. In this article, we’ll look at recent developments in NMOS and IPMX with the associations involved in defining – and refining – them, and consider the impact they might have on the IP installations of the future.
CONTROL PLANE
Networked Media Open Specifications (NMOS) – which provides discovery, registration, connection and device management capabilities within ST 2110, and is also part of IPMX (more of which anon) – is the family name for specifications produced by the Advanced Media Workflow Association (AMWA) related to networked media for professional applications. In light of NMOS’ recent announcement of what it describes as a “full control plane solution’, Installation asks Cristian Recoseanu – a leading developer for NMOS for many years, as well as development tech lead at broadcast automation, playout and management solutions company Pebble – if it would be fair to say that control and connection/device management were areas perceived as being not fully covered by previous standards projects?
“I think that whenever a very interesting product or feature is created, the almost immediate question is: “That’s incredible, now how can I make it actually do exactly what I need it to do for my use case?” he says. “We can identify this pattern in transport technologies as well, where data-plane is always associated with a counterpart control-plane model to support this necessary adaptability and customisation required in real deployments and operational uses. ST 2110 went through the same process and, on its journey to make the transition to IP networked environments using standard and interoperable means, it inevitably reached the point where the question around control-plane became loud and relevant.
“Carrying on using proprietary fragmented solutions in the control-plane had the potential to undermine the philosophy and approaches taken in the data-plane, so the emergence of the AMWA NMOS space was both timely and an extremely good fit with what had been developed in the data-plane side – only now creating a control-plane based on open and free to use interoperable specifications, using technologies underpinning the internet.”
URGENT REQUIREMENTS
The most urgent requirements of emerging IP streams were addressed with two specifications: IS-04 Discovery & Registration, allowing a means to advertise and discover media entities and signalling a shift from “static and fixed configuration to more dynamic and reactive workflows”; and IS-05: Device Connection Management, which enables the ability to configure stream emitting and consuming devices, and facilitate connections between them over an IP network. Then, more recently, the NMOS control plane solution has grown the ecosystem with specifications such as IS-12 Control Protocol, BCP-008-01: Receiver Status and BCP-008-02: Sender Status.
Recoseanu explains: “These establish interoperable standard best practices in the areas of device parameter control and monitoring in a way which leverages all the existing layers while enabling strong synergies by reusing existing technologies and shared models in addressing a wide variety of use cases. If we boil it down, from a user perspective you can discover media nodes, establish stream connections between them and, as of now, control their various processing functions and monitor any of their relevant status parameters which may indicate health issues impacting your workflows.”
Considering how the control plane innovations might impact upon pro AV, Recoseanu notes that “an expansion in the form of IPMX”, with IPMX devices being native NMOS devices and able to be discovered and connected in the same way as ST 2110 NMOS devices. He adds: “Furthermore, I see the IPMX space fully embracing the NMOS control layer and imbuing devices with abilities to control them and monitor them, fully leveraging the ecosystem and its relevant pieces and synergies. “
Moreover, there are already a number of activities looking in-depth at uses cases, some of which seem destined to support the broadcast/pro AV convergence that has been much-discussed in recent years. One example noted by Recoseanu is how IPMX devices can advertise stream issues caused by HDCP through the monitoring patterns that have already been established.
“All of this will create a convergence of broadcast and pro AV devices which can interoperate and give end-users unprecedented freedom and flexibility in choosing the best of breed devices for their workflows at different cost levels,” says Recoseanu. “NMOS control has been extremely well-received by vendors, end-users and integrators and, with the expansion of IPMX and the advent of Media Exchange Layer (MXL), interest in open, free to use interoperable solutions in this space will only continue to grow as demands and requirements from future dynamic media facilities start to trickle down to the most appropriate layer.”
SIMPLIFYING SI
Created by AIMS (the Alliance for IP Media Solutions), IPMX builds upon existing work from other organisations – such as VSF, ST 2110 from SMPTE, and NMOS from AMWA – to provide a set of open standards and specifications geared towards the requirements of the pro AV market. Enabling the carriage of compressed and uncompressed video, audio and data over IP networks, IPMX also offers provisions for control, copy protection, connection management and security that are deemed more applicable to pro AV customers and environments.
Asked to outline the main control/management capabilities included in IPMX that are not in ST 2110, Andrew Starks – marketing work group chair at AIMS, as well as director of product marketing at AIMS – responds: “ST 2110 does not define a control or management layer. The JT-NM TR-1001-1 architecture fills this gap by recommending the use of AMWA NMOS APIs, and IPMX follows that model – while introducing stricter and broader requirements tailored to pro AV.”
More specifically, IPMX mandates support for the aforementioned NMOS IS-04 (discovery and registration) and IS-05 and IS-11 (connection management), and mandates support for both mDNS for ad hoc deployments and DNS-SD for managed systems. These requirements – defined in VSF TR-10-8 – support “essential day-to-day functionality and simplify system integration – key expectations in pro AV environments.”
Starks highlights the Extended Display Identification Data (EDID)-style connection management addressed through IS-11: “Unlike ST 2110 workflows – where receivers must precisely match the source format – pro AV environments require dynamic negotiation between sources and displays. IS-11 supports this by effectively tunnelling EDID information, allowing controllers to ensure that sources send formats compatible with connected displays.”
The inclusion of IS-11 may also benefit workflows in live production. For example, in systems depending solely on IS-05, stream management is out of scope. But with IS-11, operators can define and enforce the house format, adding an extra layer of control when required.
PLUG & PLAY
In addition to the above, other NMOS specifications such as IS-12 (system parameters) exist and are fully compatible with IPMX-compliant devices. For instance, IS-12 furnishes users with a standardised way to expose and control system-level settings including network configuration and hostname.
“While not currently required by IPMX, it represents an important step toward broader interoperability,” says Starks. “Devices that do support it provide a standardised way to manage system-level parameters such as network settings and hostnames, which can be especially useful in installed environments where consistent configuration across devices is critical.” He adds that device configuration is another active area of investigation, with “several candidate approaches under discussion”.
In terms of specific AV applications to which these control and management capabilities are particularly relevant, Starks pinpoints an extensive range, including conference rooms and corporate AV systems: “In these environments, IT staff expect systems to auto-discover devices and ‘just work’ with minimal set-up. IPMX’s use of mDNS enables plug-and-play installation for ad-hoc rooms, while DNS-SD supports enterprise-level systems with centralised management. IS-11 ensures that laptops and other sources automatically send formats compatible with connected displays or projectors, eliminating user frustration and support calls.”
Other applications include digital signage networks involving one-to-many distribution across mixed displays – with IS-11 allowing “a controller to manage format compatibility across multiple endpoints dynamically” – and higher education and campus-wide AV: “Universities often deploy distributed AV systems across multiple buildings with diverse device types and inconsistent network environments. The ability for IPMX devices to operate in both registry and ad hoc modes (via NMOS + mDNS/DNS-SD) allows flexible deployment based on infrastructure maturity.”
NO CONTRADICTION
There is surely no danger of contradiction when Starks concludes: “This is not a trivial space – parameter control across best-effort networks, with a mix of hardware and software from different vendors, is a genuinely hard challenge. There’s a reason no single solution has gained universal traction yet. For IPMX, we’re taking a deliberate approach. We want to ensure that whatever mechanism we standardise is capable, future-proof, and practical for the real-world complexity of pro AV systems.”
In short, this area remains a work in progress, as one would expect. But the steady and methodical approach that has characterised the story of AV over IP during the past decade has surely proven to be the correct one – over and over again. It’s unlikely that, back in the early 2010s, many observers have predicted the scale or speed of adoption that has taken place through pro AV, broadcast and beyond. That is testament to an extraordinary amount of hard work by many people across the industry – but also to the recognition that open standards are integral to delivering universal improvements. With that now firmly established, the experience of SIs and end-users will only be improved further with the developments that reach fruition in the next few years.
This article features in Installation’s new edition.
