Daily Archives: October 4, 2014

WebRTC Media Streams

—SDP signaling and negotiation for media plane

—Media plane adaptation is done at the SBC for network carried media, —Media plane adaptation/support should be done for all network hosted media services which face peer-to-peer media clients —SBC is utilized to enhance compatibility by modifying SDP contents as necessary and engaging appropriate media servers or transcoding resources. —The high-level architecture elements of WebRTC media streams can be divided into two areas:

—Adaptation of WebRTC Media Plane to IMS Media Plane

—General  – oEncryption, RTP Multiplexing, Support for ICE —Audio -oInterworking of differing WebRTC and codec sets —Video -o Use of VP8  o Support for H.264 —Data -oSupport of MSRP ( RCS standard for messaging over DataChannel API)

—Peer-to-Peer Media

—Direct connection to media servers and media gateways ……………………… —Use common codec set wherever possible to eliminate transcoding —Use regionalized transcoding where common codec not available Note: Real-time video transcoding is expensive and performance impacting —On-going standards/device/network work needs to be done to expand common codec set. —WebRTC codec standards have not been finalized yet. WebRTC target is to support royalty free codecs within its standards. —

Media WebRTC legacy
Audio G.711, Opus G.711, AMR, AMR-WB (G.722.2)
Audio – Extended G.729a[b], G.726
Video VP8 H.264/AVC

—Supporting common codecs between VoLTE devices and WebRTC endpoints requires one or more of the following: 1.Support of WebRTC codecs on 3GPP/GSMA 2.Support of 3GPP/GSMA codecs on WebRTC 3.WebRTC browser support of codecs native to the device