Re: [AVTCORE] Registering AVP Profiles for RTP over QUIC

[Bernard Aboba <[e-mail]>]

Roman said:

"I can see a few problems that it can solve:

1. Run real-time media over WebTransport

[BA] WebTransport is a client/server protocol. So it is best suited to
applications such as low-latency streaming. Those applications typically
run over RTCDataChannel today, and many of them (e.g. game streaming, PC in
the cloud) need both P2P and client/server, so the transition to
WebTransport has been slow, particularly since the server-side development
tools are somewhat primitive (e.g. no node.js support).

2. Get rid of SCTP for data channels in the WebRTC stack

[BA] This was the motivation for the P2P QUIC trial. QUIC showed its
greatest advantage over SCTP in setup time and reliable/ordered transport.
For applications with long-lived connections or  unreliable/unordered
transport the advantages of QUIC were not as great. Also, some of the
issues with usrsctplib datachannel implementations are addressed in the new
dcSCTP implementation, and we may see further improvements with time (e.g.
support for unified congestion control).

3. Replace DTLS in secure RTP channel setup by using a more modern protocol
with cleaner implementation and faster connection establishment

[BA] QUIC-SRTP could help with this.

4. Better NAT and firewall traversal with QUIC vs. plain SRTP

[BA] This may be one of the unheralded  advantages of QUIC, but of course,
UDP traversal is required to take advantage of it, RTCDataChannel can also
do this.

On Mon, May 16, 2022 at 8:48 PM Roman Shpount <[e-mail]> wrote:

> On Mon, May 16, 2022 at 11:40 PM Ross Finlayson <[e-mail]>
> wrote:
>
>>
>>
>> > On May 16, 2022, at 8:46 PM, Roman Shpount <[e-mail]> wrote:
>> > One more question: How would you signal RTP over QUIC when it is
>> encapsulated using the RFC 4571 framing method? Is it going to be
>> TCP/QUIC/RTP/AVPF?
>> >
>> > You would end up with this encoding when RTP over QUIC is used on top
>> of TCP
>>
>> What does “QUIC on top of TCP" even mean, given that QUIC is a UDP-based
>> protocol?
>>
>
> RTP, DTLS, and SCTP are also UDP-based protocols. They all can run over
> TCP (see  RFC 4571) when the ICE-TCP (RFC 6544) candidate is used.
>
> In any case, it seems to me that this whole discussion is begging the
>> question.  First, we should come to consensus as to what problem(s) we are
>> trying to solve.  Then, and only then, we can decide whether 'RTP over
>> QUIC’ is an appropriate way to solve these problem(s).
>>
>> It may well turn out that 'RTP over QUIC’ is a solution in search of a
>> problem.
>>
>>
> I can see a few problems that it can solve:
>
> 1. Run real-time media over WebTransport
> 2. Get rid of SCTP for data channels in the WebRTC stack
> 3. Replace DTLS in secure RTP channel setup by using a more modern
> protocol with cleaner implementation and faster connection establishment
> 4. Better NAT and firewall traversal with QUIC vs. plain SRTP
> _____________
> Roman Shpount
>
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