Re: [V3] RIPT BoF approved for IETF 107 - Draft charter below

Ross Finlayson <finlayson@live555.com> Sat, 15 February 2020 06:00 UTC

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From: Ross Finlayson <finlayson@live555.com>
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Date: Sat, 15 Feb 2020 19:00:00 +1300
Cc: Spencer Dawkins at IETF <spencerdawkins.ietf@gmail.com>, "Cullen Jennings (fluffy)" <fluffy@cisco.com>, Jonathan Rosenberg <jdrosen@five9.com>, Jonathan Rosenberg <jdrosen@jdrosen.net>
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Subject: Re: [V3] RIPT BoF approved for IETF 107 - Draft charter below
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On Feb 15, 2020, at 1:15 PM, Jonathan Rosenberg <jdrosen@jdrosen.net> wrote:
> 
> RTP is in scope, in that, RIPT replaces RTP (and SDP and SIP).
> 
> Basically, the output of the codec is placed into something called a 'media chunk' which adds a few parameters which are similar to RTP (i.e., timestamp) and then sent in a PUT request or GET response.

Jonathan is ‘handwaving’ a bit here :-), as he understands (more than just about anyone) that replicating the functionality of RTP would involve a lot more than just adding a few parameters to PUT and GET.  For each media type being transported, you’d need to define how data is best framed within (QUIC) datagrams, how (optional) FEC could be used, what RTCP XR functionality will be retained (and how), how (the equivalent of) RTP header options would be defined/carried, etc. etc. etc.  Essentially, you’d be replicating all of the work that took place (over several years) within AVT to define a RTP payload format for each media type.  Therefore...


> No doubt an issue of contention will be whether we should just encapsulate RTP vs. whats in the draft.

If we want to get something standardized/working quickly, then this is a ’no brainer’, IMHO.  First, define a way to carry RTP/RTCP packets directly in QUIC datagrams - in such a way that the existing RTP payload format defined for each media type could map directly (i.e., with no more media-specific IETF standardization work required).  Even if this means that there's some duplication of functionality between RTP and QUIC (datagrams).  (Ditto for RTP over QUIC (reliable) streams.)

While - at some point in the future - it may be worthwhile defining a new version (v3?) of RTP that works more efficiently with QUIC, this should not be something that we require before we define/standardize a replacement for SIP.  Otherwise it’ll be years before we’re done.  (RTP is starting to show its age, but it’s not broken, and has lots of existing deployment that could, ideally, be leveraged quickly within a SIP replacement.


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/