Migrating data traffic from legacy networks to packet networks by inserting a first circuit emulation device (CEM) at a first endpoint and a second circuit emulation device (CEM) at a second endpoint of a connection in the legacy network, duplicating data traffic provided to the first CEM by routing one copy of the data traffic over the connection in the legacy network to the second CEM and one copy of the data traffic over a packet network from the first CEM to a comparison server, duplicating data traffic provided to the second CEM over the legacy network from the first CEM by routing one copy of the data traffic to customer communication equipment and one copy of the data traffic to the comparison server, comparing the data traffic routed to the comparison server and validating that the packet network can be used to replace the connection in the legacy network.