NMOS: What’s In It For You? Device Monitoring, minimum status reporting and More

María José Velásquez
6 days ago
5 min read

Updated: 5 days ago

If you’d like to quickly pinpoint 80-90% of the problems that are encountered in IP systems, you will want to read this part 2 blog post to find out how NMOS device monitoring – just one of the useful benefits covered below – can save you time, costs, and errors. See how NMOS Control and BCP-008 give you the minimum status reporting you need.

If you haven’t read the first blog post, which covered NMOS Connect – discovery, registration, device management, and signal management – you can read part 1 here.

Generic Control Protocol

There’s a part in NMOS that allows you to read, write, or send any kind of settings of any device. It’s an open generic layer where you can send and read all kinds of settings and it could replace a lot of legacy control protocols.

NMOS BCP-008 AMWA NMOS Control traffic lights for minimum status reporting — *Editor’s note: This is part 2 of a blog post based on the 2024 NAB presentation of Stefan Ledergerber at* *Simplexity* *in Zurich, Switzerland. You can view the full presentation* *NMOS: What’s In It For Me? on YouTube*. *Connect with Stefan on LinkedIn*.

NMOS specifies a generic control protocol that defines a certain rule set of how to communicate with each other. It is open to define what are called device models. If you’re a manufacturer, you can model all of your products and parts inside that spec. Any device model distinguishes between:

Properties, which are device settings.
Methods, which execute a functionality, so for example, hitting a play button on a machine would be a method.
Notifications, so you can subscribe to certain elements that you are interested in knowing about, and then if a value changes, you would be notified from the device.

The last one, notifications, is very important. As you know, right now, many systems require you to pole, reading out values repeatedly in order to find out whether it has changed. That's not very efficient and doesn't scale very well across big installations.

AMWA NMOS Control - Device Control & Monitoring

Device Monitoring

On the device monitoring side, AMWA members are about to finish standardizing IP-related status reporting mechanisms. It's not just a question of whether you get access to information. It goes beyond that and it's about minimizing the amount of information you're actually sending across the world. Less is more. Because nothing is more boring than looking at a screen with hundreds of messages. And in many practical cases, people operating MCR get stormed with messages, and assume they’re not relevant so they start ignoring them. NMOS allows you to reduce the storm of messages down to what’s most important.

By looking at 3 simple domain statuses that follow the analogy of traffic lights, you could probably find 80-90% of the problems you encounter in an audio/video-over-IP system. These traffic lights could at least allow an operator to call the right person quickly and address issues more efficiently.

The NMOS Reporting domains are:

Connectivity, which includes 2 traffic lights: physical link and packet level. This could be a link down or some of the links down, or packets missing, being late, or lost (on receivers) or transmission errors of any kind (on senders).
Synchronization, so is the expected synchronization present? This includes issues like PTP unlock or grandmaster change.
Stream Validation, which include issues with decoding the stream (on receivers) or invalid baseband signal to transmit (on senders).
If these 3 status reports are supported in every end device, you will be able to find most of your problems and target them quickly.

On top of these, every sender and receiver is indicating an “overall status,” as a summary of the 3 domain statuses. It takes the worst state of the 3 domains contained. By using a traffic light symbol again, this overall status could be indicated straight in your user interface. If every sender and receiver in use is indicating green, it will give you confidence that your IP system is working just fine. A yellow state would say that you should possibly check the system during the next break, but all audio/video signals are still perfectly fine. However, a red state on a sender or receiver should trigger immediate action, first by checking the 3 domain status lights, then by calling the expert on the respective domain.

NMOS BCP-008 AMWA NMOS Control traffic lights for minimum status reportin — Minimum Status Reporting with NMOS BCP-008

Since this overall status is a summary, manufacturers are welcome to add more states to the 3 “minimum status” reports, as this AMWA initiative is called. The overall status would still take those extensions into account and indicate the worst of them.

Initial Setup of Devices

The third part of Device Settings and Monitoring is an initial setup of devices. These specs explain how you take the device out of the box and get it to a default setup. There's also a backup restore functionality that’s described.

Network Security

The fourth and final focus of NMOS is security. They describe the standard mechanisms IT uses:

Control encryption of commands using HTTPS
Access authorization – how to use an authentication server
How to handle certificates

None of this is news to IT folks, but there is a need for describing how to use it in the context of NMOS, and that’s what these specifications do.

So, as an overview, what’s in the web in the image above is what NMOS describes. It's basically everything. And most of it is ready and clearly defined.

And yet, out of all of this, all that people are primarily familiar with IS-04 and IS-05. That’s what’s in the purple ovals.

Now in the next image, you can see the numbers that correspond to each function of NMOS. There's a whole channel of documents, best practices, and specifications on the NMOS website that you can read. The documents are public, and even the meeting notes are public. Get started at https://specs.amwa.tv/nmos/.

NMOS Connect and NMOS Control open specifications

What’s In It For Me?

So to sum up, if you’re an end user, NMOS can shorten your requirements engineering phase. You can leverage work done by others and actually use that work when you write your RFPs. You don't have to think it all through yourself.

With that being said, it is important to ask vendors for NMOS, but don't just write in your RFP, “It has to do NMOS.” That's just not enough. Now that you see everything that NMOS can do, you can appreciate why it’s important to get more specific with what you need.

Ultimately, it will help you build an open system with no vendor lock-in, and that will save you on costs.

And if you’re a manufacturer, NMOS shortens your requirements engineering phase. You can also leverage work already by others – specifications, coding, and testing. You don't have to do that all yourself. You can become part of a complete solution rather than just offering products. And ultimately, all of these benefits add up to saving on costs, which means you can increase your profit.

If you’re surprised to find out that NMOS can save you time, costs, and many common problems and errors, you’re invited to find out even more by joining AMWA. As a member, you can take part in working groups and the NMOS community that provide a place for open technical discussions and consensus between a wide range of end users and suppliers. Join today and be a part of the future of NMOS. Resources