Re: [Spud] Details about PLUS BoF

[Ted Hardie <[e-mail]>]

On Mon, Jun 27, 2016 at 2:28 PM, Tom Herbert <[e-mail]> wrote:

> On Mon, Jun 27, 2016 at 1:12 PM, Ted Hardie <[e-mail]> wrote:
>
> >
> > You appear to be saying that the eliminated implicit path layer simply
> > should not be replaced in UDP encapsulations unless evidence comes
> through
> > to define what information should be exposed.
> >
> Right. Consider that we want to deploy encrypted UDP-based transports
> in the near term and that no middlebox supports anything resembling
> PLUS. In the simplest model, either a network path forwards UDP
> packets without impediment or it doesn't. If it doesn't we will
> fallback to TCP and probably alert the user of that at some point. If
> PLUS does come on-line then it's worth using only if it provides some
> tangible benefit to our traffic or it "fixes" whatever networks are
> still blocking UDP.
>
>
So, having the path forward UDP packets without impediment should be a
consistent aim.  The idea behind an explicit path layer is to move from
"without impediment" to "with optimization".  If an endpoint is is willing
to inform the path of session start and stop for a UDP-based flow, for
example, it may get the longer dwell times in NAT bindings that are
currently available to flows that reveal that in an implicit path layer.
That advantage might translate to avoiding heartbeat traffic, which is
quite useful.

To put this another way, the existence of a common PLUS substrate is not
meant to imply that it will become a requirement for all UDP flows.

regards,

Ted