public function getAvailablePort(){
        $ports = $this->gameServer->gameServerDao->createQueryBuilder("gs")
            ->select("gs.port")
            ->where("status = ?1")
            ->andWhere("service_id = 4")
            ->setParameter(1, "active")
            ->getQuery()
            ->getArrayResult();
		
		for($i = $this->lowest_port; $i <= $this->highest_port; $i = $i+5){
			if(!array_key_exists($i, $ports)){
				return $i;
			}
        }
	}