550 new-who - System Port | Service Name:new-rwho

550 is a System Port. Transport Protocol TCP UDP , 550 Service Name new-rwho, Service Name Description: new-who.

Port	Protocol	Service Name	Description	Source
550	TCP UDP	new-rwho	new-who	IANA
550	TCP UDP		new-rwho, new-who,Official	wikipedia
550	TCP UDP	new-rwho	new-who	bekkoame

Port	Service Name	Description
781		Unassigned
965		Unassigned
1198	cajo-discovery	cajo reference discovery
1615	netbill-auth	NetBill Authorization Server
1958	dxadmind	CA Administration Daemon
2164	ddns-v3	Dynamic DNS Version 3
2193	drwcs	Dr.Web Enterprise Management Service
3408	BESApi	BES Api Port
3972	iconp	ict-control Protocol
4230	vrml-multi-use	VRML Multi User Systems

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