Port 725 Unassigned - System Port

Port 725 is a System Port. Transport Protocol , Port 725 Service Name , Service Name Description: Unassigned.

Port	Protocol	Service Name	Description	Source
725			Unassigned	IANA
725	TCP UDP		Mac OS X RPC-based services, Used by NetInfo, for example	Apple.com

Port	Service Name	Description
1141	mxomss	User Message Service
1894	o2server-port	O2Server Port
1948	eye2eye	eye2eye
3337	directv-catlg	Direct TV Data Catalog
3473	jaugsremotec-2	JAUGS N-G Remotec 2
3649	nmmp	Nishioka Miyuki Msg Protocol
3689	daap	Digital Audio Access Protocol (iTunes)
3858	trap-port-mom	Trap Port MOM
3883	vrpn	VR Peripheral Network
4739	ipfix	IP Flow Info Export

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