This paper is written to help railway communications engineers, network designers and architects, and network maintainers and managers understand how to migrate legacy time-division multiplexing (TDM) based communications equipment to modern packet-based networks. This paper specifically focuses on the various requirements for TDM-based applications within existing infrastructure and how best to extend the lifecycle of such assets, in the context of packet-based networks. It discusses the importance of network synchronisation and techniques to aggregate applications in an efficient manner.
