773 - System Port | Service Name:submit

773 is a System Port. Transport Protocol TCP , 773 Service Name submit, Service Name Description: .

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

Port	Service Name	Description
754	tell	send
1007		Unassigned
1639	cert-initiator	cert-initiator
2792	f5-globalsite	f5-globalsite
2818	rmlnk	rmlnk
3204	netwatcher-db	Network Watcher DB Access
3333	dec-notes	DEC Notes
3537	ni-visa-remote	Remote NI-VISA port
4146	tgcconnect	TGCConnect Beacon
4881		Reserved

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