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
523	ibm-db2	IBM-DB2
563	nntps	nntp protocol over TLS/SSL (was snntp)
1120	bnetfile	Battle.net File Transfer Protocol
1263	dka	dka
1389	iclpv-dm	Document Manager
2941	sm-pas-4	SM-PAS-4
3877	xmpcr-interface	XMPCR Interface Port
5634	xprtld	SF Message Service
6841	netmo-default	Netmo Default
7443	oracleas-https	Oracle Application Server HTTPS

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