Telephone network service logic relating to calls over the telephone network to a customer terminal, uses both terminal functions and network functions. The terminal has a service logic script for execution at the terminal to control the terminal functions. To control the execution of this script remotely from the network, a script-control message is determined and sent over the telephone network to the terminal. This may use the GR30 message format, with an additional call qualifier specific to the terminal service logic script, and the type of control being requested, e.g., start execution or terminate the script. This enables the reliability of the interaction between the service logic at the network side, and the service logic script at the terminal to be improved. This enables announcement type services to be provided in which a loudspeaker on the terminal can be remotely controlled to make verbal announcements without requiring customer action to lift a receiver.