Explanation
When supporting personal devices on a corporate network, you must protect network services and enterprise data by authenticating and authorizing users (employees, contractors, and guests) and their devices. Cisco ISE provides the tools you need to allow employees to securely use personal devices on a corporate network.
Guests can add their personal devices to the network by running the native supplicant provisioning (Network Setup Assistant), or by adding their devices to the My Devices portal.
Because native supplicant profiles are not available for all devices, users can use the My Devices portal to add these devices manually; or you can configure Bring Your Own Device (BYOD) rules to register these devices.
Reference:
/m_ise_devices_byod.html