> For the complete documentation index, see [llms.txt](https://docs.iotify.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.iotify.io/temp/protocol-settings/none.md).

# NONE

There are certain cases when the device you are simulating does not need to directly communicate with a server. It could be that you are just testing the functionality of the device, or it is an auxiliary device that connects to the server via a Gateway device. In these cases, you can use the NONE protocol which does not create a direct connection to any server.

![](/files/J4FrFFscWOR8Dsq8F0AP)

**Loopback**: The loopback setting allows you to receive whatever payload the Sender function sends into the Receiver function. This can be useful for testing the functionality of a device.