The default administrator password of HG8247, Home Gateway - Fibre to the Home is
Username: telecomadmin Password: admintelecom
Below is one example of port forwarding in HG8247 device, it is same for other ports/applications.
To port forward VPN traffic on a device (IP address as 192.168.100.3) located behind HG8247 router, you need to open UDP ports 500 and 4500 as shown here. You make sure that you leave following fields as blank - External source start port and end port, External source IP address.