279 Unassigned - System Port

279 is a System Port. Transport Protocol , 279 Service Name , Service Name Description: Unassigned.

Port	Protocol	Service Name	Description	Source
279			Unassigned	IANA
279	TCP UDP		Unassigned	bekkoame

Port	Service Name	Description
585		De-registered
835		Unassigned
1138	encrypted-admin	encrypted admin requests IANA assigned this well-formed service name as a replacement for "encrypted_admin".
1240	instantia	Instantia
1583	simbaexpress	simbaexpress
4300	corelccam	Corel CCam
6256		Unassigned
7485		Unassigned
7497		Unassigned
7498		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