Most major carriers are deploying multiprotocol label switching (MPLS) and are also migrating voice traffic to packet transport. This article analyzes how those trends can be combined. It compares the advantages of VoMPLS with VoATM, VoIP, and VoFR, from the viewpoints of bandwidth utilization, implementation issues, and the region of the network (access/backbone) in which implementation takes place. VoMPLSoPPP is more efficient than VoMPLSoATM or VoMPLSoEthernet. In the network backbone VoMPLSoPPP is most efficient. VoAAAL2oATM has intermediate efficiency, and VoIP is highly inefficient. In the access network use of header compression improves the efficiency of VoIP but does not bring it to the level of VoAAL2oATM, which is approximately as efficient as VoMPLSoEthernet. VoMPLSoPPP remains most efficient.