file descriptor.</p>
      <p>This design is particular to this application and communication
infrastructure, but provides an indication of the sort of functionality
that is needed to maintain the application-specific state for a
TCP/IP-based infrastructure.  The goal of the table and its interfaces
is threefold: First, it must guarantee that given an environment ID,
the send function can send a message to the appropriate place.  Second,
when given the special environment ID <a href="../api_reference/C/rept