An alert system for a communications network has a plurality of client
devices and a plurality of alert servers each adapted to provide alerts
to a respective subset of the client devices to provide scalability.
Users at the client devices subscribe to receive alerts by selecting a
scope of distribution of alerts. The selection involves selecting a type
of alert to receive, a level of severity of alerts to receive, and a
geographic scope. In response to receiving a request to issue an alert,
an alert server notifies the other alert servers of the alert. Each alert
server determines which client devices of the respective subset of client
devices are to receive the alert. Each alert server then sends an alert
message to its client devices that are to receive the alert.