voice vlan on EX
https://kb.juniper.net/InfoCenter/index?page=content&id=KB11062
Utilize Link Layer Discovery Protocol Media Endpoint Discovery (LLDP-MED) to provide the voice VLAN ID and 802.1p values to the attached IP phones. This dynamic method associates each IP phone with the appropriate voice VLAN and assigns the necessary 802.1p values, which are used by CoS, to differentiate service for voice traffic within a network.