Click Options in the Server Connection dialog to display the Server
  Options dialog for the currently selected session as indicated by the
  Active Sessions list in the Server Connection dialog.  The Server
  Options dialog lets you select the connection protocol, and the maximum
  number of clients that are allowed to connect to a server.

  Once a session has been established, you cannot change the connection
  protocol.  If you are the first client (the primary client) to connect
  to a server, you can control the maximum number of secondary clients
  that are allowed to connect to the server.