Service Name and Transport Protocol Port Number

Service names and port numbers are used to distinguish between different services that run over transport protocols such as TCP, UDP, DCCP, and SCTP. 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) > System Ports are assigned by IETF (Internet Engineering Task Force) > User Ports are assigned by IANA (Internet Assigned Numbers Authority) > Dynamic Ports are not assigned. Assigned ports both System and User ports SHOULD NOT be used without or prior to IANA registration.