How many cameras can be connected to an account or a smart phone at the same time?

Theoretically, it can be connected 600 cameras to an account or a smart phone at the same time. All the cameras can be viewed on computer at the same time, but they need to be viewed one by one on the smart phone.
In addition, it needs fast enough networking broadband to keep the cameras connection. Each camera will take up 0.5Mbps of the uploading networking broadband.