Using a third-party router on BT FTTP

I am using a TP-Link ER605 on my BT FTTP connection. All is working well, apart from the IPTV channels (BT Sport etc)
I have configured IGMP but the IPTV channels still do not work.

I suspect from discussion on other Forums that the MultiCast UDP packets are NOT transmitted on the PP0E interface so additional configuration may be required.
Anyone have any ideas as to where I may find some help?

I researched and solved this for the AVM Fritz!Box a few years ago. Take a look at the post for some technical details that may help you derive a configuration for the ER605:

https://forums.thinkbroadband.com/dslrouter/t/432150...

DougM, many thanks for the info, much appreciated.

I'm not intending to amend the firmware on the TP-Link Router so I will try to establish what can be achieved via the UI on the ER605.
I think the key point that I can extract from your work is that the MultiCast packets are NOT encapsulated in PPoE so will not be picked up by the existing WAN connection.
I think I need a separate WAN connection (as identified in your changes) with an IP address to receive the Multicast packets. Then I will need to create a Route to take them across onto the LAN side of the Router and also possibly a Firewall rule to make sure they're not blocked.
Does that sound like the correct approach, based on the changes you made to the Fritz 7390 formware?
cheers

Success!

The key information is that the broadcast streams are not encapsulated via PPoE but broadcast via PIM (Protocol Independent MultiCast)
The WAN connection requires another interface defined that is not a PPoE connection.
My router enabled a secondary connection to which I manually assigned a non-routable IP address. The Router was smart enough to add another route to the Routing Table to take the streamed packets (UDP, I think) across onto the LAN.
The BT Sport channels just worked, although you still need IGMP configured to make sure those Multicast packets don't flood your internal LAN
cheers

That's great news. Well done