Overview of services running on Port 123 UDP.
~217 Thousand IP addresses observed from May to December 2012
To get raw lists of the data go to Download. For an explanation of what this data is and how it was obtained, see Paper.

Servicename	Product	Version	Info	OS	Devicetype	Count	Percent
no match						122392	56.145
ntp	NTP	v4				71852	32.961
ntp	NTP	v3				22105	10.14
ntp	NTP	v4	unsynchronized			1064	0.488
ntp	Microsoft NTP			Windows		341	0.156
netbios-ssn						120	0.055
socks5						89	0.041