This is a glue layer between LWIP PPP implementation and a device type FileHandle
stream. This enables an external interface which has a FileHandle, utilize LWIP network
stack via PPP, e.g., Cellular device, WiFi chips etc.
Its totally transparent to external device. Only thing this layer is interested in, is a
FileHandle. Similar is true for for the external device, it just hands over its stream to this
PPP layer and rest of the magic is done by this layer.