When I let my own router handle the PPPoE connection, passing through the Sagemcom (the closest thing we have to a "bridge" mode in this case), I experience the following VOIP issues:
- One way audio (»
wiki.voip.ms/article/One ··· ay_Audio) - occurs with both outbound and inbound calls.
- Outbound connections that don't complete
Once a call is established, the audio quality is fine. Getting the inbound and outbound calls to complete though (and without one-way audio issues) is difficult. Probably 1 in 5 calls have this issue when I configure my router in this manner with the Sagemcom.
When the Sagemcom does the PPPoE, with the Roter in the DMZ with a DHCP reserced/assigned private IP, I experience NO Voip issues whatsoever.
Although I didn't mention it in my original reply to OP, I also saw varying download speedtest values for the connection when my Router handles the PPPoE connection. My Bell Fibe 25/7 service would drop to 15 during roughly half of my speedtest runs and end up somewhere between 15 and 25 on the other 50%. When letting the Sagemcom handle the PPPoE and putting my router in the Sagemcom's DMZ (with a DHCP assigned/reserved IP from the Sagemcom) my download speed was consistently at 25 mbits/s.
In any case, the passthrough functionality with the Sagemcom is a poor option compared to an actual bridge mode.