3915 Auto-Graphics Cataloging - User Port

3915 is a User Port. Transport Protocol TCP UDP , 3915 Service Name agcat, Service Name Description: Auto-Graphics Cataloging.

Port	Protocol	Service Name	Description	Source
3915	TCP UDP	agcat	Auto-Graphics Cataloging	IANA
3915	TCP UDP	agcat	Auto-Graphics Cataloging	bekkoame

Port	Service Name	Description
982		Unassigned
1233	univ-appserver	Universal App Server
1336	ischat	Instant Service Chat
1934	xaapi	IBM LM Appl Agent
2221	rockwell-csp1	Rockwell CSP1
4427	drizzle	Drizzle database server
4463		Unassigned
4944		Unassigned
6291		Unassigned
6425		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