RPC Mechanism

The Trusted Extensions software provides multilevel port support for remote procedure calls (RPCs). A client application can send inquiries to a server's PORTMAPPER service (port 111) whether or not a particular service is available. If the requested service is registered with the PORTMAPPER on the server, the server will dynamically allocate an anonymous port and return this port to the client.

On a Trusted Extensions system, an administrator can configure the PORTMAPPER port as a multilevel port so that multiple single-level applications can use this service. If the PORTMAPPER port is made a multilevel port, all anonymous ports allocated by the PORTMAPPER service are also multilevel ports. There are no other programmable interfaces or administrative interfaces to control anonymous multilevel ports.