4430 REAL SQL Server - User Port | Service Name:rsqlserver

4430 is a User Port. Transport Protocol TCP UDP , 4430 Service Name rsqlserver, Service Name Description: REAL SQL Server.

Port	Protocol	Service Name	Description	Source
4430	TCP UDP	rsqlserver	REAL SQL Server	IANA

Port	Service Name	Description
636	ldaps	ldap protocol over TLS/SSL (was sldap)
653	repscmd	RepCmd
772	cycleserv2
1192	caids-sensor	caids sensors channel
1759	spss-lm	SPSS License Manager
1832	tht-treasure	ThoughtTreasure
2100	amiganetfs	Amiga Network Filesystem
2178	bitspeer	Peer Services for BITS
2851	webemshttp	webemshttp
6451		Unassigned

A port is an endpoint of communication in an operating system. While the term is also used for hardware devices, in software it is a logical construct that identifies a specific process or a type of service.

Port numbers are assigned in various ways, based on three ranges: System Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private Ports (49152-65535);

The Well Known Ports are assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users. Ports are used in the TCP [RFC793] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port". To the extent possible, these same port assignments are used with the UDP [RFC768]. The range for well-known ports managed by the IANA is 0-1023.
DYNAMIC AND/OR PRIVATE PORTS Registered Ports are those from 1024 through 49151.
The Dynamic and/or Private Ports are those from 49152 through 65535