The analysis of common channel signaling under broadband environments such as ATM is needed to characterize the performance of various SS7 signaling network topologies. The paper presents an analysis of Broadband-ISDN signaling network architectures in an ATM environment. The components of an SS7 network such as SSP, STP and SCP can be configured in various SS7 signaling network architectures or signaling network models, utilizing an ATM transport infrastructure. We propose two new SS7 network architectures: the flat network model and the hybrid network model running on B-ISDN environments. We have analysed our proposed network architectures and compared them to the traditional hierarchical network architecture with respect to bandwidth consumed, call switching and call flow through the network. The results show that the proposed architectures perform significantly better than the traditional signaling architecture. We hence show that efficient use of the underlying broadband transport and switching infrastructure can significantly improve the performance of signaling network architectures.