IoT architecture question

Hi,

I have a question related to an IoT architecture I'm putting in place. I would like using Service Bus to process sensor data (coming from sensors connected to edge-devices) in Azure Cloud and to command actuators (connected to edge devices). For the latter I will use webpages and smartphone apps.

My question:

- should i from a webpage/smartphone app send the messages Service Bus (e.g. a topic)directly (e.g. from JavaScript in the browser)

or

- should I from a webpage/smartphone app call an ASP.NET REST service (Web API) and this REST service (Web API) sends the messages to Service Bus (e.g. a topic)?

Thanks

Guy