Portmap

Portmap is a server used to make RPC calls and map RPC program numbers into DARPA protocol port numbers. Portmap is an Open Network Computing Remote Procedure Call (ONC RPC) service that must be running to make a RPC call. Clients making a RPC call to an ONC RPC server contact the portmapper on the server for determining which TCP or UDP port is to be used. Portmapper assigns port number for each of the requests.