While the notion of a Distributed DBMS has been familiar to the IT industry for several decades, within telecom networks the subscriber data management based on DDBMS technology is a novel addition to a service provider's infrastructure. Service providers are used to telecom networks that are efficient, reliable and easy to maintain and operate, in part thanks to the node model used in designing such networks. A DDBMS spanning a large geographical area however incurs into distributed systems issues not previously seen in telecom networks. Identifying and delivering the right set of trade-offs that satisfies the service providers' needs while staying within the known physical bounds of a distributed system is therefore crucial if DDBMS are to conquer the subscriber management space within telecom networks.