SMPTE's ST 2110 standard is actually a suite of standards which define how to move essences over IP for live production. The term essences referrs to video, audio and metadata as all are of high importance for most broadcast workflows. It's best known for detailing how to carry uncompressed audio and video, but now also includes carriage of lightly compressed video such as JPEG-XS. The common thread throughout all that ST 2110 defines is almost zero latency allowing for tier 1 live production. Whilst there were other ways of doing uncompressed video over IP before SMPTE 2110, it is now the de facto standard for essence based transport over IP.
ST 2110 is split into subject areas, each area getting a numbered section:
2110-1x is for timing
2110-10 - Defines referring RTP to a PTP clock (SMPTE 2059-2)
2110-2x is for video
2110-20 - Transport of uncompressed active-video data
2110-21 - Timing model for -10 video RTP streams
2110-22. - Transport of constant bit-rate compressed video
2110-3x is for audio
2110-30 - Transport of AES67
2110-31 - Transport of AES3
2110-4x is for metadata
2110-40 - Transport of Anicllary Data packets (SMPTE ST 291-1)
SMPTE ST-2110-10: System Timing and Definitions – covers the fundamental packet formats used throughout 2110 (RTP over UDP), packet size limits, system timing model (based on SMPTE ST-2059-2), and specifies SDP (Session Description Protocol) as the required method for describing individual media sources.
Video: SMPTE ST-2110-20: Uncompressed Active Video - covers the transmission of uncompressed video. It brings efficiency to video transport by transporting only the visible part of the video (i.e. only active pixels, so not the HANC or VANC ancillary data space) thereby significantly reducing the volume of data transported. Raw pixel data is arranged into IP packets with a common timestamp for all of the packets that make up a single frame of video, in a manner similar to RFC 4175. The SDP parameters that are used to precisely describe video essence are also defined in this part.
Packet timing: SMPTE ST-2210-21: Timing Model for Uncompressed Active Video - defines a model for the packet delivery timing characteristics of video streams as they leave the IP transmission interface of the sender.
Audio: SMPTE ST-2110-30: PCM Digital Audio - covers uncompressed audio transport in close conformance to AES67, with a few modifications to simplify compatibility with IP video signals.
Extended audio: SMPTE ST-2210-31: AES3 Transparent Transport: this is an extension to SMPTE ST-2110-30, which defines the transparent transport of the full AES3 signal (including the 8-bit sample ‘headers’ in addition to the audio payload).
Ancillary Data: SMPTE ST-2110-40: Ancillary data - covers the transport of ancillary data such time-related essence elements (such as closed captions and subtitles) and metadata about the video and audio signals such as AFD and audio metadata, as specified by SMPTE ST-291-1. The new RFC 8331, on which this part of the standard is based, has now been published.