Just add a rule to accept/allow connection to port 3306 (MySQL). However, it's better to put a rule to just allow connection from some known IP Addresses / host names for security reasons.
You will require to put your source IP(s) in MySQL Access Control list to allow remote connections over network. Default MySQL only allows connection from localhost (127.0.0.1). Please refer MySQL Docs for Access Control.
where is this ACL located i configured mysql frm source /usr/local/mysql
In my mysql server where the databes is located , i have edited the /etc/my.cnf and did the following : bind-address = host ip # skip-networking
i also log to mysql and GRANT ALL PRIVILEGES ON *.* TO root@client'sipaddress IDENTIFIED BY 'root's_password';
quit;