Port 631 IPP (Internet Printing Protocol) - System Port

Port 631 is a System Port. Transport Protocol TCP UDP , Port 631 Service Name ipp, Service Name Description: IPP (Internet Printing Protocol).

Port	Protocol	Service Name	Description	Source
631	TCP UDP	ipp	IPP (Internet Printing Protocol)	IANA
631	TCP UDP		Internet Printing Protocol (IPP),Official	wikipedia
631	TCP UDP		Common Unix Printing System (CUPS),Unofficial	wikipedia
631	TCP UDP		Mac OS X RPC-based services, Used by NetInfo, for example	Apple.com
631	TCP		Internet Printing Protocol (IPP), Mac OS X Printer Sharing, Printing to many common printers	Apple.com
631	TCP UDP	ipp	IPP (Internet Printing Protocol)	bekkoame

Port	Service Name	Description
437	comscm	comscm
2559	lstp	LSTP
2787	piccolo	piccolo - Cornerstone Software
3777	jibe-eb	Jibe EdgeBurst
3797	idps	idps
4219	vrml-multi-use	VRML Multi User Systems
6121	spdy	SPDY for a faster web
6611		Unassigned
6668	ircu	IRCU
6790	hnmp	HNMP

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