It's most probably a problem with the Ntl modem interface. I get cut off occasionly for no good reason but not as much as you seem to be experiencing. Your calls are routed to a bank of Modems and if one of these modem cards go faulty then all sorts of weird things happen. Logs are generated and usually if one card seems to be failing a lot of connections it is taken out of service either by itself or the internet NMC until it can be replaced. The interfaces Ntl use are not the most reliable!!
