3855 OpenTRAC - User Port | Service Name:opentrac

3855 is a User Port. Transport Protocol TCP UDP , 3855 Service Name opentrac, Service Name Description: OpenTRAC.

Port	Protocol	Service Name	Description	Source
3855	TCP UDP	opentrac	OpenTRAC	IANA
3855	TCP UDP	opentrac	OpenTRAC	bekkoame

Port	Service Name	Description
1873	fjmpjps	Fjmpjps
2728	sqdr	SQDR
2875	dxmessagebase2	DX Message Base Transport Protocol
4182	pcptcpservice	Production Company Pro TCP Service
6048	x11	X Window System
6453		Unassigned
6574		Unassigned
7282	mzca-action	eventACTION/ussACTION (MZCA) server
9348		Unassigned
9449		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