161 SNMP - System Port | Service Name:snmp

161 is a System Port. Transport Protocol TCP UDP , 161 Service Name snmp, Service Name Description: SNMP.

Port	Protocol	Service Name	Description	Source
161	TCP UDP	snmp	SNMP	IANA
161	UDP		Simple Network Management Protocol (SNMP),Official	wikipedia
161	UDP		Simple Network Management Protocol (SNMP)	Apple.com
161	TCP UDP	snmp	SNMP	bekkoame

Port	Service Name	Description
1977	tcoaddressbook	TCO Address Book
2684	mpnjsosv	mpnjsosv
3275	samd	SAMD
4326	geognosis	Cadcorp GeognoSIS Service
5464	quailnet	Quail Networks Object Broker
5516		Unassigned
7109		Unassigned
7430	xmpv7	OpenView DM xmpv7 api pipe
8869		Unassigned
10505		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