206 AppleTalk Zone Information - System Port

206 is a System Port. Transport Protocol TCP UDP , 206 Service Name at-zis, Service Name Description: AppleTalk Zone Information.

Port	Protocol	Service Name	Description	Source
206	TCP UDP	at-zis	AppleTalk Zone Information	IANA
206	TCP UDP	at-zis	AppleTalk Zone Information	bekkoame

Port	Service Name	Description
979		Unassigned
2668	alarm-clock-c	Alarm Clock Client
4683	spike	Spike Clipboard Service
4883	wmlserver	Meier-Phelps License Server
5586		Unassigned
5608		Unassigned
5617		Unassigned
6498		Unassigned
6635		Unassigned
6676		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