This disclosure relates to generating telecommunication network measurements. In one aspect, a method includes presenting, by a client device, a digital component that, when interacted with, initiates a call by the client device to a phone number specified by the digital component. A trusted program stores, in a presentation event data structure, a presentation event data element specifying the phone number and resource locator for a reporting system to which reports for the digital component are sent. The trusted program detects a phone call by the client device to a given phone number. The given phone number is compared to one or more presentation event data elements stored in the presentation event data structure. A determination is made that the given phone number matches the phone number specified by the digital component. In response, an event report is transmitted to the reporting system.