As the telecommunications industry evolves, and broadband services start to arrive, customers are increasingly coming to expect the perception of instantaneous access to service providers, together with transparency to network failures. System performance dictates that response times need to be minimised, sufficient redundant capacity be installed in case of failure, and controls be embedded within the design to manage the exceptional situations (such as media-stimulated events) that continually threaten network integrity. A vital part of this system is the broadband signalling network, which underpins the dialogue with the customer, and which enables the delivery of the service.
Network design based on a ‘top-down‘, ‘end-to-end’ methodology plays a fundamental role in delivering solutions that meet customers’ performance needs. Simple, approximate performance models at an early stage in this life cycle are valuable to uncover major performance problems which affect the design of the architecture. Performance issues identified can then be fed back into the design process in an iterative way, to ensure that the design solution will conform to performance requirements.
This paper outlines performance studies of a number of design scenarios for providing broadband services. These studies consider interactive multimedia services, looking at service demand, physical network topology, signalling message flows, the mapping of functional entities to physical components, and routeing, as part of the network design process. The most significant performance issues identified relate to bottle-necks, capacity requirements, and load-dependent response times as perceived by the customer.