We are developing a non-PC embedded Host that will interface via USB to various cellphone Devices, one of them being the Nokia 5300. Using TotalPhase's USB monitor between a PC driver and the 5300, we copied the transmission details (SETUP, IN, OUT packets) into the CDC firmware to enable the 5300 to act as a modem. There are the usual Standard Device Requests, but there are also NON-Standard Device Requests that we do NOT recognize. The 5300 also responds with some unknown data upon receipt of RING. How do we identify the protocol between the Host and the device (5300) to successfully implement the 5300 as a modem?
Thanks in advance, Roland Feibert