A telecommunications server (2) controlling a plurality of telecommunications terminals (4) connected to a packet switched telecommunications system (40, 41), responds to call events (20) by transmitting an alert (251, 252) to each of the terminals. If the server is not capable of processing all the required event alerts in parallel, it processes the event alerts to the terminals in a predetermined sequence, according to stored prioritization rules (60). The priority accorded to an individual terminal may be set according to the alert mode (visual-only, or audible) currently set for that terminal (or the user currently using the terminal) for that call type or calling party.