ST 2110 and
NMOS Support
Uncompressed video
over IP
ST 2110 and NMOS are a suite of standards for high speed, low latency video transmission over standard IP networks. Not to be confused with ordinary streaming solutions: ST 2110 transports uncompressed video with sub-frame latencies. Under Windows, these timing constraints can only be reliably met using specialized hardware. Ventuz initially supports boards by Deltacast, Blackmagic Design and AJA.
Media and control networks
ST 2110 distinguishes between the media network and the control network:
- Media network: carries the high speed video, audio and ancillary streams as well as PTP.
- Control network: used for NMOS and other non-time-critical traffic.
As network packet loss or delay of singular packets can be an issue in an IP switched environment, it is common to have two media networks, where the transmitter sends the data twice over two network interfaces and completely separate cables and switches, and the receiver gets both streams over two network interfaces, choosing the first uncorrupted packet it gets. This is called Seamless Protection Switching, or ST 2022-7 (SPS).
So an ST 2110 board might have three network interfaces, two media and one control, or it may have only one network interface, sharing media and control over the same interface.
ST 2110 and NMOS at a glance
Defines the transport of video, audio and ancillary data over the network.
An optional layer that allows discovery of ST 2110 devices and connects outputs to inputs.
ST 2110 usually uses multicast, meaning that any output can be switched to many inputs, or none.
ST 2110 devices are configured using the same Device Configuration application as SDI hardware and mix with SDI, NDI and other devices.
NMOS is handled by software provided by the board vendors, which overrides the initial device configuration by Ventuz. ST 2110 can also be configured by manually copying SDP files within the device configuration, or with vendor supplied tools.
ST 2110 is synchronized using the Precision Time Protocol (PTP), which replaces blackburst and genlock signals. A large installation will usually require a PTP grandmaster clock, which typically comes in the form of a 1U 19 inch rack module.
Board speeds
At the moment, ST 2110 boards come at three speeds:
- 10 Gbit/s
- 25 Gbit/s
- 100 Gbit/s
If two media interfaces are present, they do not improve speed but just add ST 2022-7 SPS.
As a rule of thumb, you can compare these network speeds with SDI speeds: a 10 Gbit/s network can carry the equivalent of 3 x 3G SDI, but not 12G SDI. Remember that actual bandwidth calculations are more complicated, and many boards have other limits. In theory, a 100 Gbit/s network can carry 8 x 12G transmission and reception at the same time.
Supported hardware
Deltacast
Deltacast IP boards are a great fit for large installations, offering two media networks and a separate control network. The 10 Gbit/s board is supported right now; it can do either input or output, switching between the two requires a firmware change. The 25 Gbit/s board will be supported as soon as its firmware is finished.
Blackmagic Design
Blackmagic offers a range of 10 Gbit/s boards with a single combined media and control network adapter, and a 100 Gbit/s board with two media adapters for SPS that share the control network. These boards work particularly well for small installations inside the Blackmagic ecosystem, with the IP 360 switch and peer to peer NMOS that does not require additional servers.
AJA
AJA offers a 25 Gbit/s IP board with two media and a separate control network adapter, ideal for large installations. ST 2110 parameters are configured exclusively via a network interface reachable from the board's media or control network adapter, which poses no restriction in real world setups where NMOS is used. Support for AJA is currently under development and will be available very soon.
A moving ecosystem
This year has been full of product releases, and new products are scheduled, as well as firmware upgrades that redefine existing products.
Complex infrastructure
Unfortunately, ST 2110 and NMOS are much more complicated than SDI. You cannot just plug in a cable and expect it to work, and you cannot just attach a Tektronix to see what is going wrong if it does not. There are opportunities for misconfiguration and incompatibilities at the sender, the receiver, the switching infrastructure, the NMOS registry and the NMOS controller, down to the kind of cable you are allowed to use.
