542 commerce - System Port | Service Name:commerce

542 is a System Port. Transport Protocol TCP UDP , 542 Service Name commerce, Service Name Description: commerce.

Port	Protocol	Service Name	Description	Source
542	TCP UDP	commerce	commerce	IANA
542	TCP UDP		commerce (Commerce Applications),Official	wikipedia
542	TCP UDP	commerce	commerce	bekkoame

Port	Service Name	Description
807		Unassigned
1381	apple-licman	Apple Network License Manager
2682		Removed
3649	nmmp	Nishioka Miyuki Msg Protocol
3921	herodotus-net	Herodotus Net
4419		Unassigned
4653		Unassigned
5341		Unassigned
6011	x11	X Window System
7146		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