[RSSAC Caucus] Updating the RSSAC FAQ

[Dave Lawrence]

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.