tcp limitations

[Guy Pazi]

> >                                                  Will a root
> server answer 10k
> >  TCP queries/sec?
>
> 	No.  Absolutely not.  99.9999999% of all DNS queries are purely
> UDP, although this percentage is reducing as more and more sites make
> use of things like DNSSEC, having too many MXes advertised, etc...
> and cause truncation of the UDP response, which should then be
> restarted with TCP.

But, lets say for a minute, all queries were tcp. What ~ number of
queries/sec will a root name server support drop down to, from the 2-5k udp
queries/sec?

Thanks
Guy