An ISP provides VoIP and internet services to its customers. For security reasons, these services must be transported in different MPLS Layer 3 VPNs over the ISP core network. The customer CEs do not have the ability to segment the services using different VLANs and have only one uplink interface that does not support VLAN tagging. How should you design the network to ensure that VoIP traffic that is received from the CE goes in the VoIP VPN, and that Internet traffic goes into the Internet VPN on the ISP PE devices?