730 IBM NetView DM/6000 send/tcp - System Port

730 is a System Port. Transport Protocol TCP UDP , 730 Service Name netviewdm2, Service Name Description: IBM NetView DM/6000 send/tcp.

Port	Protocol	Service Name	Description	Source
730	TCP UDP	netviewdm2	IBM NetView DM/6000 send/tcp	IANA
730	TCP UDP		Mac OS X RPC-based services, Used by NetInfo, for example	Apple.com
730	TCP UDP	netviewdm2	IBM NetView DM/6000 send tcp	bekkoame

Port	Service Name	Description
1293	pkt-krb-ipsec	PKT-KRB-IPSec
2032	blackboard
2708	banyan-net	Banyan-Net
3353	fatpipe	FATPIPE
3783	bim-pem	Impact Mgr./PEM Gateway
5709		Unassigned
5758		Unassigned
5831		Unassigned
6888	muse	MUSE
7294		Unassigned

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