SMPTE ST 2110 is the industry reference for transporting professional video, audio and metadata streams over managed IP networks. The standard separates image, sound and ancillary data as individual, synchronised RTP streams, enabling multi-vendor interoperability, scalable studio and remote workflows, and native cloud/virtualisation integration.
What is SMPTE ST 2110?
SMPTE ST 2110 is not a single protocol, but rather a family of standards that describes how and which professional media streams (video, audio, ancillary/timed text, etc.) are transported, synchronised and described over IP networks.
Key features:
- stream-based approach (separate streams)
- uncompressed signal transmission
- RTP/UDP as a carrier medium
- SDP-signals
- PTP-based synchronisation (SMPTE ST-2059)
- clear rules for timing/traffic shaping
The stream-based approach distinguishes between further subcategories under ST-2110.
SMPTE ST 2110-10 defines the system timing architecture and requirements that apply to all streams. It uses the RTP timestamp and SDP signalling to regulate synchronisation across all separately transmitted data streams using PTP / ST 2059. Absolute, frame/sample-accurate synchronisation is achieved via IEEE 1588 PTPv2 (SMPTE profile ST-2059). The PTP provides the common time base to which the RTP timestamps are referenced in order to precisely synchronise video, audio and ancillary streams. A robust PTP domain design (grandmaster, boundary/transparent clocks) is essential for this. At the same time, ST 2110 requires discipline in network design, testing and interoperability.
The subcategory ST 2110-20 is used to transmit uncompressed video signals over IP networks. (Marked in green in the figure)
Another stream, ST 2110-21, defines traffic shaping and timing for the delivery of uncompressed video to ensure smooth transmission. For this purpose, a distinction is made between different transmitter classes (N, NL, W) so that the packets are delivered at the appropriate time.
ST 2110-30 is used to transport PCM/AES67 audio over IP networks. (Marked in orange in the figure) ST 2110-31 transports AES3 transparent audio streams.
Ergänzend sorgt ST 2110-40/-43 für die Übertragung der „Ancillary Data“, also der benötigten Zusatzdaten als jeweils unabhängige RTP/UDP-Sessions. (Blau markiert in der Abbildung)
Why is this relevant for broadcasters?
A conventional studio that transmits signals from point to point using SDI is significantly less flexible than IP-based transmission. The use of a router/switch allows any number of streams to be distributed to multiple recipients. The use of ST2110 significantly increases the flexibility of a broadcast studio, which is also reflected in vendor neutrality and interoperability. Standardised RTP payloads and the use of NMOS for discovery/connection allow for multi-vendor infrastructures instead of isolated solutions. At the same time, this creates the possibility of enabling a modern workflow within the studio, e.g. through remote/distributed productions, cloud playout, microservices-based processing and software-defined video.
To date, there are only a few end devices that are already “IP-ready”, such as KAIROS from Panasonic, which is why so-called encoders and decoders are used when building or renovating a studio. These ensure translation between the SDI and ST-2110 protocols. This is particularly useful for conversions, as existing components can be replaced gradually rather than all at once.
future-proofing
SMPTE ST 2110 offers great future-proofing thanks to several factors. The modular principle makes it possible to integrate new codecs, audio formats or metadata types without redesigning the studio infrastructure. Streams can be routed, scaled and orchestrated in containers/VMs. In addition, time-critical Ethernet technologies such as TSN (IEEE 802.1) reconcile deterministic latency and future convergence of broadcast IP networks.
In summary, SMPTE ST 2110 is the industry standard for IP-based live production and studio infrastructure: modular, mature and widely established in the field.
For system integrators, this means that investing in ST 2110-enabled architecture, PTP expertise and NMOS orchestration pays off in the long term, especially for scalable remote and cloud workflows and multi-vendor integrations.
Further information can be found at https://www.smpte.org/standards/st2110
