Well known ports, 21000 to 21999

Ports 20000 to 20999 Ports 22000 to 22999

Links: IANA port assignments.

PortTransportProtocol
21000TCP, UDPIRTrans Control.
21001
-
21552
  
21553TCPRaima RDM TFS.
21554TCP, UDPMineScape Design File Server.
21555
-
21589
  
21590 VoFR Gateway.
21591
-
21844
   
21845   webphone.
21846   NetSpeak Corp. Directory Services.
21847   NetSpeak Corp. Connection Services.
21848 NetSpeak Corp. Automatic Call Distribution.
21849 NetSpeak Corp. Credit Processing System.
21850
-
21999
  

Ports 20000 to 20999 Ports 22000 to 22999