[RSSAC Caucus] Updating the RSSAC FAQ

[Geoff Huston]

> On 2 May 2020, at 1:25 am, Dave Lawrence <tale at dd.org> wrote:
> 
> Geoff Huston writes:
>> "Finally, many more resolvers today are capable of falling back to
>> TCP when they receive a truncated response over UDP” 
>> 
>> really? Where is the study that publishes this finding?
> 
> It could use clarification, certainly, beyond just the fuzziness of
> "many more".  There are several metrics which could all claim to be
> relevant.  A few of them seem like they are probably true in raw
> numbers if only because of overall growth over the past couple of
> decades (and yes, good measurement would confirm that).  Like:
> 
> * Total number of implementations
> * Total number of running servers
> * Total number of people served (not strictly a resolver, but still relevant)
> 
> But, maybe that picture changes when you ask about the percent of the
> whole, and then "many more" might not apply.
> 
> Measurement rules, for sure.  I also don't think it is entirely out of
> place to make a qualified claim based on our cumulative anecdotal
> experience that overall the TCP fallback scenario is improved now vs
> the past, as long as it clear that it is supposition rather than data.
> 

My measurements of TCP use from time to time report that the relative number of
users that sit behind recursive resolvers that cannot perform TCP appear 
to be unchanged for the 6 years that I’ve looked (from time tim time). Now
there are many ways of reporting DNS (resolvers, users, queries, … as well as
absolute numbers or relative numbers). 

Therefore I don't understand the basis of the TCP claim in that report - it seems
apocryphal to me 

Geoff