you are right, FB is running probably (as application?), i can connect to DB locally.
but I need to connect to this server from remote - so I need listening port. and (probably) while service not running, no listenig, no remote connection.
i allready have gds_db 3050/tcp #Firebird in /etc/services
and I have allready looked to docs, everything seems fine, just FB service not running. maybe xinetd call FB, but it dont look like I have listening port.