Draft proposes a thumbnail solution to early media for consideration/discussion by the working group.
Next step from draft-stucker-sipping-early-media-coping-03 which identified various problems that exist within SIP for early media today.
Mechanism uses secondary dialogs to specifically handle early media.
URL supplied via new header “Early-Media” in response message.
Discrimination of early/final media streams handled by using a unique dynamic RTP payload for early media endpoints.
Endpoint can switch over to next media stream when it detects a change in payload type to the preferred media stream, or additional “Early-Media” URL in SIP provisional.
Alternative to RFC-3959.
Minimal new protocol requirements.