SMPTE began work in January 2016 to develop a set of standards (documented as SMPTE ST-2110) specifying the carriage, synchronization, and description of separate elementary essence streams over IP for the purposes of live production, based on VSF Technical Recommendations TR-03 and TR-04 (see above). SMPTE 2110 is now the de facto standard for essence based transport over IP.
SMPTE 2110 comprises multiple parts, which at the time of writing (August 2018) are at different stages of definition and approval. The following have now been published:
System timing: 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.
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.
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).