I have a PFsense load balancing router, its lan is connected to wan1 of MT and I use MT for PPPOE server, however, speed coming out of PPPOE server in MT is half that of connecting directly to LAN coming out of PFsense, I have done many different tests on diff pppoe servers and get the same result, what is it about PPPOE servers that slow the data throughtput?
Could be an MTU mismatch. Fragmenting (or discarding DF packets) would decrease throughput.