Overview of services running on Port 1521 TCP.
~78 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
oracle-tns	Oracle TNS Listener					69816	89.454
irc	Dancer ircd					3439	4.406
chat	AIM or ICQ server					1376	1.763
no match						1034	1.325
http	WangWnagSimpleServer	1.0				441	0.565
http						389	0.498
http	lighttpd	1.4.19				322	0.413
http	Microsoft IIS httpd					169	0.217
http	Microsoft HTTPAPI httpd	2.0	SSDP/UPnP	Windows		107	0.137
ssh			protocol 1.5			65	0.083
ftp	Microsoft ftpd			Windows		46	0.059
ftp						38	0.049
arcserve	ARCserve Discovery					38	0.049
ssh	OpenSSH	4.3	protocol 2.0			37	0.047
telnet						35	0.045
socks4	Connection ok					35	0.045
http	Boa HTTPd	0.94.14rc21				30	0.038
vnc	VNC		protocol 3.8			24	0.031
nntp	INN nntpd		posting ok			22	0.028
oracle-mts	Oracle MTS Recovery Service					21	0.027
oracle	Oracle Database					20	0.026