Have a customer plugged directly into Comcast router (LIPU and BIPU) everything works fine for weeks then all phones drop and connection is not restored until cards are reset. We have replaced both cards and cards are on latest and greatest firmware but problem still happens. Cards are in cabinet 2 slot 3 and 5 and slots 4 and 6 are vacant. SPI and firewall are off on the router and it appears to happen around the same time every month.