7544 FlowAnalyzer DisplayServer - User Port

7544 is a User Port. Transport Protocol TCP UDP , 7544 Service Name nta-ds, Service Name Description: FlowAnalyzer DisplayServer.

Port	Protocol	Service Name	Description	Source
7544	TCP UDP	nta-ds	FlowAnalyzer DisplayServer	IANA
7544	UDP		QuickTime Streaming Server	Apple.com
7544	TCP UDP	nta-ds	FlowAnalyzer DisplayServer	bekkoame

Port	Service Name	Description
1004		Unassigned
1836	ste-smsc	ste-smsc
2331	agentview	AGENTVIEW
2581	argis-te	ARGIS TE
2853	ispipes	ISPipes
4797		Unassigned
5429	base	Billing and Accounting System Exchange
5490		Unassigned
5812		Unassigned
5847		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