SMPTE ST 2110

showstack / protocols / smpte-st-2110

Also called ST 2110, 2110, SMPTE 2110.

A suite of SMPTE standards for carrying uncompressed video, audio and ancillary data as separate RTP streams over a managed IP network, all locked to PTP. It is the broadcast plant replacement for an SDI router, used in OB trucks, studios and large arena control rooms.

Video transportPaid specSMPTEReported

Stewarded by SMPTE (Society of Motion Picture and Television Engineers).

Media Large, continuous, on time and in order

Continuous streams that are large enough to be sized properly, and that must arrive in order and on time.

What kills it. Anything that starves the link — usually a management transfer nobody scheduled — and jitter that outruns the receive buffer.

The four flows, and why the model is worth having →

Multicast

Streams are normally multicast, but the suite does not reserve an address range. Addresses are assigned by the facility and handed to receivers in the SDP, usually via a broadcast controller rather than typed in by hand.

What it carries

Sample rates: 48 kHz
Audio bit depth: 16-bit, 24-bit
Audio encoding: ST 2110-30, which is AES67
Resolution: Not fixed by the specification
Frame rate: Not fixed by the specification
Colour sampling: 4:2:2, 4:4:4
Video bit depth: 8-bit, 10-bit, 12-bit, 16-bit
Video compression: None — uncompressed essence

Audio: Essence streams are separate, so audio and video are independently routable — which is the whole point of 2110 and the reason lip sync becomes something you have to manage rather than something you get.

Video: ST 2110-20 is resolution and frame-rate agnostic by design; what limits you is the link. Uncompressed HD is around 1.5 Gbit/s and UHD around 12 Gbit/s, so the practical ceiling is the network rather than the standard. Audio travels separately in ST 2110-30 as AES67.

What goes wrong

Video, audio and ancillary data are separate streams with separate multicast addresses. Losing one leaves the others running, so "no audio" or "no timecode" can present as a perfectly healthy video path.

Everything hangs off PTP. ST 2110-10 defines the system timing model, so a grandmaster that steps, or two grandmasters fighting, takes the whole plant out at once rather than degrading gracefully.

ST 2110-20 video is genuinely uncompressed. Bandwidth is set by raster and frame rate, not by an average bitrate, so plan link capacity from the video format and leave headroom before you commit to a switch.

ST 2110-21 defines sender traffic shaping types. A sender and a receiver with mismatched shaping expectations gives intermittent picture breakup under load, not a clean failure you can point at.

ST 2110-30 audio is closely related to AES67 but the two do not automatically interoperate. Packet time and channel count profiles have to match on both ends before anything passes.

The suite is a dozen separate documents (ST 2110-10, -20, -21, -22, -30, -31, -40, -41, -43, plus RPs) and they are priced individually. Budget for the whole set, not one part number.

What speaks SMPTE ST 2110 (7)

Product	Direction	Notes
Smode Smode Tech	bidirectional	ST 2110 on suitably equipped systems.
vMix StudioCoast	bidirectional	On higher tiers with suitable hardware.
Analog Way Alta 4K Analog Way	bidirectional	Depending on option.
Brompton Tessera S8 Brompton Technology	in	IP video with the relevant option.
Brompton Tessera SX40 Brompton Technology	in	ST 2110 input on suitably licensed systems.
Megapixel HELIOS LED Processing Platform Megapixel VR	in	IP video input.
Modulo Kinetic Modulo Pi	bidirectional	ST 2110 on suitably equipped nodes.

Open source implementations

EBU LIST (pi-list) — C++, GPL-3.0-or-later

Typical use

IP video routing in broadcast facilities and OB trucks
Arena and stadium control rooms replacing large SDI routers
Carrying camera, replay and graphics feeds on shared network infrastructure
Audio (ST 2110-30) alongside video on the same physical network

The words for it

Glossary entries that name SMPTE ST 2110, with the false friends that catch people out.

Latency延遲The time between something happening and the system showing or sounding it. Every conversion, network hop, sc…Multicast多播Sending one copy of a stream to a group address that many receivers can subscribe to, instead of one copy per…QoS (quality of service)服務品質Marking packets so a switch knows which ones to send first when a link is congested. On a media network the c…

Sources

ST 2110 Suite of Standards — SMPTE primary
SMPTE ST 2110 FAQ — SMPTE primary
SMPTE Publishes ST 2110 Standards for Professional Media Over Managed IP Networks — TV Tech

Understand the mechanism

Show networks Node graphs and game engines

Something wrong, or missing?

Known gaps on this entry: default_ports. If you can source one of them, that is a ten minute pull request.

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