CDP on your Device
The Cisco Discovery Protocol (CDP) service allows your device to find the voice VLAN advertised by the switch. If it is present, your device then communicates with the voice VLAN rather than the default VLAN.
The CDP service only works if your device is using a wired Ethernet network connection. The CDP service is on and running by default. If you want to change this setting, see the following section.
Change CDP on your Device
Tap the system name at the top of the home screen, and tap Settings.
Tap Network connection and Ethernet.
Toggle CDP (Cisco Discovery Protocol) On or Off.
Tap when you're done.