摘要 |
A method of providing a service, such as local number portability (LNP), in a switched telecommunications system, in which a message interceptor is disposed in a signalling link of an SS7 signalling network of the system. The message interceptor detects calls for which service implementation is required, by comparing the content of intercepted circuit-related SS7 messages with service trigger conditions, such as message type (checked directly by the interceptor) and message content (e.g. called number, which the interceptor checks by reference to a database). When service implementation is detected as being required, the message interceptor may implement at least part of the required service by modifying parameters of the intercepted message; alternatively, the interceptor may re-direct the message to a service control function for service implementation. The invention enables services to be implemented without incurring inefficient use of core network resources, and without expensive and time-consuming modification of switch and SCP control software. <IMAGE> |