671 VACDSM-APP - System Port | Service Name:vacdsm-app

671 is a System Port. Transport Protocol TCP UDP , 671 Service Name vacdsm-app, Service Name Description: VACDSM-APP.

Port	Protocol	Service Name	Description	Source
671	TCP UDP	vacdsm-app	VACDSM-APP	IANA
671	TCP UDP		Mac OS X RPC-based services, Used by NetInfo, for example	Apple.com
671	TCP UDP	vacdsm-app	VACDSM-APP	bekkoame

Port	Service Name	Description
157	knet-cmp	KNET/VM Command/Message Protocol
230		Reserved
366	odmr	ODMR
417	onmux	Onmux
2055	iop	Iliad-Odyssey Protocol
2080	autodesk-nlm	Autodesk NLM (FLEXlm)
2339	3com-webview	3Com WebView
2601	discp-client	discp client
4659	playsta2-lob	PlayStation2 Lobby Port
4967		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