1021 RFC3692-style Experiment 1 - System Port

1021 is a System Port. Transport Protocol TCP UDP , 1021 Service Name exp1, Service Name Description: RFC3692-style Experiment 1.

Port	Protocol	Service Name	Description	Source
1021	TCP UDP	exp1	RFC3692-style Experiment 1	IANA
1021	SCTP	exp1	RFC3692-style Experiment 1	IANA
1021	DCCP	exp1	RFC3692-style Experiment 1	IANA
1021	TCP UDP		Mac OS X RPC-based services, Used by NetInfo, for example	Apple.com
1021	TCP		Webus	bekkoame

Port	Service Name	Description
505	mailbox-lm	mailbox-lm
712	tbrpf	TBRPF
2084	sunclustergeo	SunCluster Geographic
2590	idotdist	idotdist
3750	cbos-ip-port	CBOS/IP ncapsalation port
3985	mapper-mapethd	MAPPER TCP/IP server
4303	srcp	Simple Railroad Command Protocol
5798		Unassigned
5999	cvsup	CVSup
8020	intu-ec-svcdisc	Intuit Entitlement Service and Discovery

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