734 Unassigned - System Port

734 is a System Port. Transport Protocol , 734 Service Name , Service Name Description: Unassigned.

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

Port	Service Name	Description
1216	etebac5	ETEBAC 5
1374	molly	EPI Software Systems
3350	findviatv	FINDVIATV
3843	quest-agent	Quest Common Agent
4928		Unassigned
5427	sco-peer-tta	SCO-PEER-TTA
5614		Unassigned
6666	ircu	IRCU
7240		Unassigned
7246		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