Video: A Frank Discussion of NMOS

What NMOS isn’t is almost as important as what NMOS actually is when it comes to defining a new project implementing SMPTE ST 2110. Written by AMWA, NMOS is a suite of open specifications which help control media flow hence the name: Network Media Open Specifications. Typically NMOS specifications are used alongside the ST 2110 standards but in this hype-free panel, we hear that 2110 isn’t the only application of NMOS.

AMWA Executive Director Brad Gilmer introduces this ‘frank’ panel with Imagine’s John Mailhot explaining the two meanings ‘NMOS’ has. The first is the name of the project we have just introduced in this article. The second is as shorthand for the two best-known specifications created by the project, IS-04 and IS-05. Together, these allow new devices to register their availability to the rest of the system and to receive instructions regarding sending media streams. There are plenty of other specifications which are explained in this talk of which two more are mentioned later in this video: IS-08 which manages audio channel mapping and IS-09 which allows new devices to get a global configuration to automatically find out facts like their PTP domain.

 

 

Security is “important and missing previously,” says Jed Deame from Nextera but explains that since NMOS is predominantly a specification for HTTP API calls, there is nothing to stop this from happening as HTTPS or another protocol as long as it provides both encryption and authorisation. The panel then explores the limits of the scope of NMOS. For security, its scope is to secure the NMOS control traffic, so doesn’t stretch to securing the media transport or, say, PTP. Furthermore, for NMOS as a whole, it’s important to remember it defines control and not more than control. Brad says, though, that even this scope is ambiguous as where does the concept of ‘control’ stop? Is a business management system control? What about scheduling of media? Triggering playback? There have to be limited.

Imagine Communications’ John Mailhot explores the idea of control asking how much automation, and hence NMOS-style control, can help realise one of the promises of IP which is to reduces costs by speeding up system changes. Previously, Brad and John explain, changing a studio from doing NFL to doing NHL may take up to a month of rewiring and reprogramming. Now that rewiring can be done in software, John contends that the main task is to make sure the NMOS is fully-fledged enough to allow interoperable enumeration, configuration and programming of links within the system. The current specifications are being reinforced by ‘modelling’ work whereby the internal logical blocks of equipment, say an RGB gain control, can be advertised to the network as a whole rather than simply advertising a single ‘black box’ like an encoder. Now it’s possible to explain what pre and post-processing is available.

Another important topic explored by NVIDIA’s Richard Hastie and Jeremy Nightingale from Macnica, is the use of NMOS specifications outside of ST 2110 installations. Richard says that NVIDIA is using NMOS in over 200 different locations. He emphasises its use for media whether that be HEVC, AV1 or 2110. As such, he envisages it being used by ‘Twitch streamers’ no doubt with the help of the 2110-over-WAN work which is ongoing to find ways to expose NMOS information over public networks. Jeremy’s interest is in IPMX for ProAV where ‘plug and play’ as well as security are two of the main features being designed into the package.

Lastly, there’s a call out to the tools available. Since NMOS is an open specification project, the tools are released as Open Source which companies being encouraged to use the codebase in products or for testing. Not only is there a reference client, but Sony and BBC have released an NMOS testing tool and EasyNMOS provides a containerised implementation of IS-04 and IS-05 for extremely quick deployments of the toolset.

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Speakers

Brad Gilmer Brad Gilmer
Executive Director, Video Services Forum
Executive Director, Advanced Media Workflow Association (AMWA)
John Mailhot John Mailhot
CTO Networking & Infrastructure
Jed Deame Jed Deame
CEO,
Nextera Video
Richard Hastie Richard Hastie
Senior Sales Director,
NVIDIA
Jeremy Nightingale
President
Macnica Americas, Inc.

Video: What is NMOS? with a Secure Control Case Study

Once you’ve implemented SMPTE ST 2110‘s suite of standards on your network, you’ve still got all your work ahead of you in order to implement large-scale workflows. How are you doing to discover new devices? How will you make or change connections between devices? How will you associate audios to the video? Creating a functioning system requires an whole ecosystem of control protocols and information exchange which is exactly what AMWA, the Advanced Media Workflow Association has been working on for many years now.

Jed Deame from Nextera introduces the main specifications that have been developed to work hand-in-hand with uncompressed workflows. All prefixed with IS- which stands for ‘Interface Specificaion’, they are IS-04, IS-05, IS-08, IS-09 and IS-10. Between them they allow you to discover new devices, create connections between then, manage the association of audio with video as well as manage system-wide information. Each of these, Jed goes through in turn. The only relevant ones which are skipped are IS-06 which allows devices to communicate northbound to an SDN controller and IS-07 which manages GPI and tally information.

Jed sets the scene by describing an example ST-2110 setup with devices able to join a network, register their presence and be quickly involved in routing events. He then looks at the first specification in today’s talk, NMOS IS-04. IS-04’s job is to provide an API for nodes (cameras, monitors etc.) to use when they start up to talk to a central registry and lodge some details for further communication. The registry contains a GUID for every resource which covers nodes, devices, sources, flows, senders and receivers. IS-04 also provides a query API for controllers (for instance a control panel).

While IS-04 started off very basic, as it’s moved to version 1.4, it’s added HTTPS transport, paged queries and support for connection management with IS-05 and IS-06. IS-04 is a foundational part of the system allowing each element to have an identity, track when entities are changes and update clients accordingly.

IS-05 manages connections between senders and receivers allowing changes to be immediate or set for the future. It allows, for example, querying of a sender to get the multicast settings and provides for sending that to a receiver. Naturally, when a change has been made, it will update the IS-04 registry.

IS-08 helps manage the complexity which is wrought by allowing all audios to flow separately from the video. Whilst this is a boon for flexibility and reduces much unnecessary processing (in extracting and recombining audio) it also adds a burden of tracking which audios should be used where. IS-08 is the answer from AMWA on how to manage this complexity. This can be used in association with BCP-002 (Best Current Practice) which allows for essences in the IS-04 registry to be tagged showing how they were grouped when they were created.

Jed looks next at IS-09 which he explains provides a way for global facts of the system to be distributed to all devices. Examples of this would be whether HTTPS is in use in the facility, syslog servers, the registration server address and NMOS versions supported.

Security is the topic of the last part of talk. As we’ve seen, IS-04 already allows for encrypted API traffic, and this is mandated in the EBU’s TR-1001. However BCP 003 and IS-10 have also been created to improve this further. IS-10 deals with authorisation to make sure that only intended controllers, senders and receivers are allowed access to the system. And it’s the difference between encryption (confidentiality) and authorisation which Jed looks at next.

It’s no accident that security implementations in AMWA specifications shares a lot in common with widely deployed security practices already in use elsewhere. In fact, in security, if you can at all avoid developing your own system, you should avoid it. In use here is the PKI system and TLS encryption we use on every secure website. Jed steppes through how this works and the importance of the cipher suite which lives under TLS.

The final part of this talk is a case study where a customer required encrypted control, an authorisation server, 4K video over 1GbE, essence encryption, unified routing interface and KVM capabilities. Jed explains how this can all be achieved with the existing specifications or an extension non top of them. Extending the encryption methods for the API to essences allowed them to meet the encryption requirements and adding some other calls on top of the existing NMOS provided a unified routing interface which allowed setting modes on equipment.

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For more information, download these slides from a SMPTE UK Section meeting on NMOS
Speakers

Jed Deame Jed Deame
CEO,
Nextera Video

Video: What’s New in NMOS? – A Tutorial on the Latest in Video over IP Control and Security

The Networked Media Open Specifications (NMOS) have been developed to provide a control and management layer along side the SMPTE ST 2110 transport layer. The idea behind NMOS was to deliver an open specification to provide the software layers that abstract a lot of complexities of ST 2110 and make it easy to interface with any control system.

The NMOS family of specifications began with projects for Discovery & Registration, Device Connection Management and Network Control, but has grown to include many other important subjects such as Event & Tally, Audio Channel Mapping and Interoperable Security.

In this video, Jed Deame discusses the latest advancements including IS-08, IS-09, BCP-002, BCP-003 and IS-10. These additions allows NMOS to surpass the level of control provided in SDI while also adding a layer of security.

The following Interface Specifications and Best Current Practices are presented:

  • IS-04 (Registration and Discovery) – new features: support for GPI over Ethernet (IS-07) and authorisation signalling for security layers BCP-003-02
  • IS-05 (Connection Management) – new features: MQ Telemetry Transport and WebSocket Transport, support for supplementary externally defined parameters
  • IS-08 (Audio Mapping) – audio routing / shuffling facility
  • IS-09 (System Resources) – System ID, server priority, security with HTTPS support, advertisement of system resources such as RDS (Registration and Discovery Server)
  • BCP-002 (Grouping) – uses tag resources in IS-04 in order to achieve a natural groups of senders and receivers (e.g. to tie audio, video and metadata)
  • BCP-003-01 (Security) – uses Transport Layer Security (TLS) in order to encrypt communications between API servers and their clients
  • BCP-003-02 (Security) – covers client authorization for the NMOS APIs
  • IS-10 (Authorisation API) – accompanies the BCP-003-02 specification to restrict what users are authorized to change in an NMOS system (core technologies: PKI, HTTPS, REST, JSON, Oauth 2.0 and JWT)

The presentation finishes with the customer case study – secure KVM all over an IP network.

You can download the slides from here.

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You might also be interested in the following videos we have published on The Broadcast Knowledge:

Speaker

Jed Deame
CEO
Nextera Video