I have a question on QoS. We have 4 sites connected on a MPLS circuit with a SonicWall at each site along with a Layer 3 Core switch. We have a data VLAN of 1 and a voice VLAN of 5. We have dedicated VoIP switches going to the core switch. The core switch has a single uplink to a SonicWall on the data VLAN, the SonicWall then goes to the ADVA router out on the MPLS to other sites. Each site is the same way. The Core Switch routes the traffic between VLANs and routes the traffic to the firewalls.
My first question is do I need to tag the voice VLAN on the uplink to the firewall in order to use QoS? Or will it pass the QoS tag for the voice traffic and pick it up on the other site with the QoS tagging? Right now the uplink is just an untagged data port and there are routes back to the core switch for the Voice VLAN.