RTP Taxonomy & draft-lennox-raiarea-rtp-grouping-taxonomy-03 IETF 88 1

Changes Since -02 Major re-write – Section 2, Concepts, re-structured to a conceptual media chain with Streams and Transformations – Section 3, Relations, re-organized and added descriptions of a few more functional relations – Section 4, Communication Entities, aligned taxonomy with Section 2

Way Forward Is the draft ready enough for WG adoption?

Media Streams and Transformations The flow of media signal undergoes a series of transformations from the source to the sink Transformations: Encoder, Decoder, … Media Streams: Encoded Stream, Source Stream, …

Media Streams and Transformations o A transformation may have zero or more input Streams and one or more output Streams. o A Stream is of some type. o A Stream has one source transformation and one or more sink transformations. o Streams can be forwarded from a transformation output to any number of inputs on other transformations that support that type. o If the output of a transformation is sent to multiple transformations, those streams will be identical; it takes a transformation to make them different. o There are no formal limitations on how streams are connected to transformations, this may include loops if required by a particular transformation.

Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Media Transport(2) Physical Stimulus Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R)

Media Transport(2) Raw Stream Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R)

Media Transport(2) Source Stream Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R)

Media Transport(2) Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R) Encoded Stream

Media Transport(2) Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R) Source Packet Stream

Media Capture (Audio) Media Source (Audio) Media Transport (1) Media Source (Video) Media Packetizer (Simulcast 1) Media Capture (Video) Media Encoder (Simulcast 2) Media Encoder (Simulcast 1) Media Encoder (Audio) Media Packetizer (Audio) Media Packetizer (Simulcast 2) Media Redundancy (Simulcast 2 R) Media Transport (2) Media Redundancy (Simulcast 1 R) Audio, Video with 2 simulcast streams w/repair stream - (Sender Side) Redundancy Packet Stream

Received Packet Stream, Received Redundancy Packet Stream Media Sink (Audio) Media Transport (1) Media Depacketizer (Simulcast 1) Media Decoder (Simulcast 2) Media Decoder (Simulcast 1) Media Decoder (Audio) Media Depacketizer (Audio) Media DePacketizer (Simulcast 2) Media Transport (2) Media Repair Media Sink (Simulcast 1) Media Sink (Simulcast 2) Audio, Video with 2 simulcast streams w/repair stream - (Recv Side) Media Renderer (Simulcast 2) Media Renderer (Simulcast 1) Media Renderer (Audio)

Repaired Packet Stream Audio, Video with 2 simulcast streams w/repair stream - (Recv Side) Media Sink (Audio) Media Transport (1) Media Depacketizer (Simulcast 1) Media Decoder (Simulcast 2) Media Decoder (Simulcast 1) Media Decoder (Audio) Media Depacketizer (Audio) Media DePacketizer (Simulcast 2) Media Transport (2) Media Repair Media Sink (Simulcast 1) Media Sink (Simulcast 2) Media Renderer (Simulcast 2) Media Renderer (Simulcast 1) Media Renderer (Audio)

Received Encoded Stream Audio, Video with 2 simulcast streams w/repair stream - (Recv Side) Media Sink (Audio) Media Transport (1) Media Depacketizer (Simulcast 1) Media Decoder (Simulcast 2) Media Decoder (Simulcast 1) Media Decoder (Audio) Media Depacketizer (Audio) Media DePacketizer (Simulcast 2) Media Transport (2) Media Repair Media Sink (Simulcast 1) Media Sink (Simulcast 2) Media Renderer (Simulcast 2) Media Renderer (Simulcast 1) Media Renderer (Audio)

Received Source Stream Audio, Video with 2 simulcast streams w/repair stream - (Recv Side) Media Sink (Audio) Media Transport (1) Media Depacketizer (Simulcast 1) Media Decoder (Simulcast 2) Media Decoder (Simulcast 1) Media Decoder (Audio) Media Depacketizer (Audio) Media DePacketizer (Simulcast 2) Media Transport (2) Media Repair Media Sink (Simulcast 1) Media Sink (Simulcast 2) Media Renderer (Simulcast 2) Media Renderer (Simulcast 1) Media Renderer (Audio)

Received Raw Stream Audio, Video with 2 simulcast streams w/repair stream - (Recv Side) Media Sink (Audio) Media Transport (1) Media Depacketizer (Simulcast 1) Media Decoder (Simulcast 2) Media Decoder (Simulcast 1) Media Decoder (Audio) Media Depacketizer (Audio) Media DePacketizer (Simulcast 2) Media Transport (2) Media Repair Media Sink (Simulcast 1) Media Sink (Simulcast 2) Media Renderer (Simulcast 2) Media Renderer (Simulcast 1) Media Renderer (Audio)

Media Transport Sender Received Packet Stream Media Transport Receiver Network Transport Transported Packet Stream Sent Packet Stream Packet Stream Media Transport Detailed

Communication Entities

End Point RTP Session A single addressable entity sending or receiving RTP packets. It may be decomposed into several functional blocks, but as long as it behaves as a single RTP stack entity it is classified as a single "End Point". An association among a group of participants communicating with RTP. It is a group communications channel which can potentially carry a number of Packet Streams. Within an RTP Session, every participant can find meta-data and control information (over RTCP) about all the Packet Streams in the RTP session.

Participant Multimedia Session An entity reachable by a single signaling address, and is thus related more to the signaling context than to the media context. A Participant can have multiple Multimedia Sessions. An association among a group of participants engaged in the communication via one or more RTP Sessions. It defines logical relationships among Media Sources that appear in multiple RTP Sessions. A Multimedia Session can be composed of several parallel RTP Sessions with potentially multiple Packet Streams per RTP Session.

Communication Session An association among group of Participants communicating with each other via a set of Multimedia Sessions. Each Participant in a Communication Session is identified via an application specific signaling address. A Communication Session is composed of at least one Multimedia Session per Participant, involving one or more parallel RTP Sessions with potentially multiple Packet Streams per RTP Session.

Concept Relations

Relations at Different Levels The reason why a relation is needed on one level may be functionality on a different level – E.g. Simulcast relate Packet Streams to identify a common Media Source Briefly describes a set of existing functional relations in taxonomy terms – Synchronization – Simulcast – Layered encoding – Robustness and repair

Topologies and Communication Entities

Point-to-Point Communication Participant A EndPoint A Participant B EndPoint B RTP Audio Session RTP Video Session Media Transport Multimedia Session (SIP Dialog) Communication Session

Remaining Issues To what extent should terminology used in existing RTP-related RFCs be clarified and mapped onto the proposed taxonomy by the draft? Are there more functionalities involving Stream relations that should be described? To what extent should Stream relation and identification needs from different RTP Topologies be elaborated? More?

Thank You