NTP vs SNTP - it's more than this skewing issue,-snip-
The last RFC that was only SNTP was 4330 - that has been obsoleted by-snip-
5905. http://tools.ietf.org/html/rfc5905 is a place to look at it.
The RFC, if I read it correctly, says that the only thing different is
the mitigation - so skewing is certainly available to SNTP, as Chuck
Anyhow, NTP on IBM i is SNTP according to RFC 2030, I think - a
predecessor of 4330. Same with the AIX version. Not sure about any Java