A new extended property should be added to enable support for goog-remb. This will be set by a channel driver that wants to enable support for it (such as chan_pjsip).
If the goog-remb extended property is not set then the below should not occur.
If an RTCP feedback message containing REMB Is received perform the following:
- Place the REMB packet into an AST_FRAME_RTCP frame.
- Set the stream number on the AST_FRAME_RTCP frame to correspond to the stream the REMB packet is in regards to.
- Modify the REMB packet to have a zero SSRC for both SSRCs.
- Return the AST_FRAME_RTCP frame from res_rtp_asterisk.
If an RTCP feedback message containing REMB is provided to ast_rtp_instance_write:
- Update the REMB packet to contain the correct SSRCs.
- Send the REMB packet in an RTCP feedback message on the correct stream.
The abs-send-time specification (which is small) should be implemented according to the goog-remb draft.
If an RTP packet is sent:
- Add abs-send-time information to the packet