[rtcweb] Layers in draft-jesup-rtcweb-data-00

[Hadriel Kaplan <[e-mail]>]

Howdy,
Just to make sure I understand this right, the choice isn't really this:

        +------+                    +------+
        |WEBAPP|                    |WEBAPP|
        +------+                    +------+
        | DTLS |                    | SCTP |
 +-------------+             +-------------+
 | STUN | SCTP |             | STUN | DTLS |
 +-------------+             +-------------+
 |    UDP      |             |    UDP      |
 +-------------+             +-------------+

But rather this:

        +------+                        +------+
        |WEBAPP|                        |WEBAPP|
        +------+------+------+          +------+------+------+
        | DTLS | Audio| Video|          | SCTP | Audio| Video|
 +---------------------------+   +---------------------------+
 | STUN | SCTP |S/RTP |S/RTP |   | STUN | DTLS |S/RTP |S/RTP |
 +---------------------------+   +---------------------------+
 |         Mux/Demux         |   |         Mux/Demux         |
 +---------------------------+   +---------------------------+
 |            UDP            |   |            UDP            |
 +---------------------------+   +---------------------------+

[Note: "S/RTP" = SRTP/SRTCP or RTP/RTCP, "Mux/Demux" = tiny logic to mux/demux]

Because the audio/video streams may be using the same UDP port, right?

And the two "S/RTP" boxes may be just one box depending on how the MMUSIC multiplexing decision turns out.

So if we want to choose the left one, because we expect/want that someday the Operating System provides a SCTP/UDP stack in the kernel, and I think we do, could it do so while demuxing and letting STUN, RTP, and DTLS go up to the app layer?  (i.e., given a socket/BIO/FD model)  I have no idea about such things... just asking.

-hadriel