I’ve been using foscam cams and software viewers since years now. I acquired a new cam FI9800P model. This foscam pro2 viewer (even the foscam pro version) works fine when within my internal wifi network (with all camera models) but once i want to view it from the outside (DDNS - 3G/4G network) it doesn’t work anymore for this model only (FI9800P). The fun part is that using a competitor viewer (IP CAM Viewer Pro) it works fine !!! Thus, i strongly suspect a foscam pro2 viewer bug !! . Tested on iPhone 6+ & iPhone 6s - last iOS version Please contact me to fix the issue asap - available to help you analyse the behaviour.