Fiware：上下文注册的providerApplication属性-IDAS UltraLight

Question

Each time that a new device connects to an IoT agent, the IoT agent sends an updateContext to the context broker and a new context entity is created. And if this device has some lazy attribute the IoT agent will send a contextentityRegistration in order to create a context registration, to indicate to the context broker how can connect to the device.

But when the Context Registration is created, I'm not sure about the value that will be assigned to the providingApplication attribute.

• It is used the ip:port of the IoT agent where it listens to the context broker requests?
• or should it be the URL of the device?

Although I'm not sure, I believe the correct one it's the first option, because the device normally won't understand the NGSI protocol, and the IoT agent should translate the request before sending it to the device. If that's the case, then:

1. It is necessary some initial configuration, or when the IoT agent creates a new context Registration automatically establishes itself as the context provider?
2. Regarding the property "commands" used when a new device is registered by the IoT agent, what's their functionality? Are they used by the IoT agent to translate any request from the context broker addressed to the device?

Thanks in advance, any help would be grateful.

Answer 1

2) The property "commands" is used to define attributes of the ContextBroker entity that will actually tirgger a command to the device if they are updated using the NGSI API. This means tahta developers are able to read observations and also send commands just using one API (NGSI) with no knowledge of the specific device technology or protocol.

1) In UL2.0 lazy attributes are not supported so far. Please refer to the other IoT Agents for that. Normally the IoT Agent IP:Port should be used for that.

Cheers,