Well 16M is less than a second's worth of traffic these days.

You may want to tune -U #listeners down from the default and/or the
number if cpus (-n) which reduces -U.

That said the ability to set this size at runtime would be useful.
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org