The option -S <service> is used to specify the service (port) on which SAProuter runs (default 3299). SAProuter can, for example, be started on any other service: saprouter -r -S 4444 (AS/400: saprouter '-r -S 4444' ) starts SAProuter on the local host on service 4444. If you want to administer this SAProuter, of course you also have to define the service.