IP is the predominant traffic type for packet services in transport networks; any expansion strategy for transport should also consider the nature of IP demands. This paper shares insights on how to plan the expansion of IP and transport networks in a holistic way and how IP can co-exist with lower layers of Transmission (DWDM, OTN, SDH, and L2 ( MPLS-TP ). The paper also discusses how such an approach of carrying traffic on the appropriate layer will also help reduce the TCO (Total Cost of Ownership) of the core network.