Performance, models and topologies of common channel signalling system number seven.
An Intelligent Network (IN) can be visualised as a central computer interconnected to the telecommunication network that allows the creation and deployment of services as consumer demand arises. Messages or information are transferred between the central processor and exchanges by a standardised form of signalling, known as Common Channel Signalling System Number Seven (CCS7). The thesis focuses on CCS7 performance, models and topologies. A requirement of the research entails the study of the CCS7 performance parameters: signalling delays and signalling network dependability. Signalling delays may be comprised of signalling message transfer delays within the message transfer part and queueing delays. Signalling network dependability usually include availability, reliability, maintainability and network robustness. For the purpose of modelling, the decomposition of the CCS7 message transfer part into subsystems is essential. A generic model for the message transfer part was used to implement certain functionalities of CCS7 in OPNET. OPNET (Optimised Network Engineering Tools) is a comprehensive engineering system capable of simulating large communication networks with detailed protocol modelling and performance analysis. The simulation software (OPNET) and performance parameters were used to analyse CCS7 networks resulting in the selection of a particular topology for a given region. The network structures analysed include the mesh topology, standard quad topology, hierarchical topology and Telstra's new topology. It was found that the mesh structure had the best simulated and availability/reliability results but was impractical for large networks due to the cost implications. This cost factor led to the selection of a hierarchical signalling system for Kwa-Zulu Natal.