plz refer to the below link as it gives full details on the bug
Now I can't see how it can be mpd problem. As I see from forum messages, mpd sends PATR, but provider doesn't responds with PADS. So I see four possible cases: PADR was written improperly for some reason, PADR was not transmitted by NIC, PADR was not transmitted by modem or PADR was dropped by provider because of something. First point could be analyzed if I could see tcpdump for normal and problem case, but I can't download any of them. Second part could be checked using some Ethernet hub between host and modem. Last two points require cooperation with provider.
Could you upload dumps here?
heres the last trace as mentioned in the forum
its clear from the forum that the BRAS has some sort of protection and doesnt allow to initiate a new connection till the zombie connection is brought down which is only possible by a link down
attached trace is taken with a switch in between pfsense and the modem