IGMP/Multicast over PPPoE link on 80e

[ARP]

I am planning to deploy FG80e and having PPPoE uplink, also going to get IPTV traffic from same uplink.

what type of configuration will be required to forward IGMP/Multicast traffic over PPPoE link? 

Client <---> Fortigate <----->ISP PPPoE uplink + IPTV server 

Thanks in Advance. 

[ARP]

I am able to make this work after enabling MC forwarding and do't change TTL setting.

This works fine with one client behind the box, but when i have 2 or more clients it stops working if one of the client changes to different  stream. 

any suggestion? 

Thanks

[Micha_S]

How did you get this working? I want to receive MagentaTV via PPPoE, but cannot see any interaction on that interface, when I start a video player on the inside network.

Perhaps you have any hints or config sniplets?