285 Unassigned - System Port

285 is a System Port. Transport Protocol , 285 Service Name , Service Name Description: Unassigned.

Port	Protocol	Description	Source
285		Unassigned	IANA
285		Delf	simovits.com
285	TCP UDP	Unassigned	bekkoame

Port	Service Name	Description
1297	sdproxy	sdproxy
1661	netview-aix-1	netview-aix-1
2601	discp-client	discp client
2616	appswitch-emp	appswitch-emp
2921	cesdcdman	CESD Contents Delivery Management
3712	sentinel-ent	Sentinel Enterprise
3743	ipcs-command	IP Control Systems Ltd.
3899	itv-control	ITV Port
4437		Unassigned
6772		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