Réponse de draytek reçue ce jour:

Thank you for your information.
Vigor2860 is able to handle multiple internet connection via one VDSL link, actually that is what Multi-PVC/VLAN is used for.
I think we should stay on the configuration you have in  Réponse #1.
So the issue about that configuration is that VoD is not working, right? Multicast TV and Internet works fine?

If you'd like to try the bridging setting, we do NOT need to set up WAN2 and VLAN configuration.
maybe we should try enable "Port-based Bridge Connection" for Channel 5, and select the port that  is connecting to the TV as physical member. (just like part C in Réponse #47)

Ok so here is my actual configuration:

Lan2 : My PC
Lan3 : A switch with  other equipments
Lan5 : My Set Top Box (via a CPL adapter)

As mentioned by Draytek i'm  back with the initial configuration, except for the Wan5, as requested i did it that way:


In this case here is the result:

Nothing in Wan5

To get Wan5 "working" (geting an ip address from DHCP), i have to check Open WAN Interface for this Channel.

Nouvelle réponse de Draytek:

We'd like to confirm that in Applications >> IGMP page, was IGMP Proxy set to WAN? Because from the packets, it seems like the IGMP packets are sent out from WAN1 interface. Could you set it to PVC/VLAN for a try?
 During your test, please also capture WAN packets by Wireshark, as well as the packets from the LAN port that is connecting to the set-top box. (This can be done by enable that LAN port in LAN Port Mirror function)

 On the other hand, open port-based bridge means the router will make the device on the bridging port connected directly to the ISP. therefore, it's the set-top box which will obtain an IP address from your ISP, but not the router's interface WAN5.

 Before we look into the DHCP option issue, we'd like to make sure how your VoD and multicast TV works. Do you know if the VoD service is also based on IGMP as well? Thank you very much for your help!

was IGMP Proxy set to WAN?... Could you set it to PVC/VLAN for a try?
Yes, because when i set it to something else than WAN1 the TV is not working, but i'll try again.

Do you know if the VoD service is also based on IGMP as well?
Kgersen ou quelqu'un d'autre peut-il nous éclairer sur ce point ? au vu du graphique de Kgersen je ne pense pas que ce soit de l'igmp mais je préfère qu'on me confirme...

oui mais ca ne me surprends pas, si Draytek France avait pris la main sur le sujet je pense qu'ils auraient les moyens de reproduire le scenario avec une ligne Orange+TV, faire leurs tests etc...Là ils doivent se dire mais qu'est-ce que c'est que ce truc de ouf qu'ils font en France 

Lors de mes échanges avec Draytek France les 2 interlocuteurs que j'ai eu signaient leur emails avec: Technicien support sous leur nom.

@cetipabo : Essaies PC_MLTV_IHD92 pour voir.

Si ça se trouve orange fait la liaison livebox/STB et vu qu'on envoie livebox 3 il s'attend peut-être à recevoir un user-class de STB play ?