When provisioning non-Cisco phones on a Cisco-switched network, you may notice that the configured voice VLAN is not correctly provisioned to the phone. The phone ends up in the data VLAN, rather than the voice VLAN even though the switch port has been correctly configured.

There are two protocols which can be used to provision the correct VLAN to your phones: Cisco Discovery Protocol (CDP) and Link-Layer Discovery Protocol (LLDP). CDP is a proprietary protocol and is only supported on Cisco-switches and Cisco-phones. Non-Cisco devices usually use LLDP, which is an open standard supported by most other vendors. Although Cisco switches also support LLDP, it is by default not enabled, resulti  ...