There are many things that happen during an alarm. The system will take multiple actions to ensure that others are notified about the alarm event. Some of the most important actions include activating sirens and sending outbound signals to alert the end user and/or a central station. Assuming that the alarm is not a silent alarm or an auxiliary alarm, then the siren will activate. This includes the panel's internal sounder and any added sirens. This will probably be the first thing you notice during an alarm event, as the siren will be quite loud. For more information about how loud a siren should be, please review this FAQ. If the panel is monitored, then there are more important things going on behind the scenes during alarm events. Most notably, the panel will be sending outbound signals. Most modern alarm panels send alerts across a cellular network or an IP network. Some panels use dual-path communication and send signals across both cellular and internet. A panel will need an alarm monitoring communicator and active monitoring service in order to do this. When an alarm system sends signals across an IP or cellular network, the signals are received by an alarm reporting service. Most Alarm Grid customers will have their systems connected with either the Alarm.com Servers or the AlarmNet Servers. This will depend on the alarm monitoring communicator installed inside the system. For reference, most Honeywell and Resideo Panels will use AlarmNet. Most of our other panels will use Alarm.com. But there are exceptions to this rule. The alarm reporting service will then forward the alarm to a central station and/or the end user. This will depend on the user's monitoring service. A central station dispatcher who receives an alarm report will contact the local authorities for emergency dispatch. The dispatcher may attempt to contact the end user first. Again, this will depend on the instructions listed on the end user's account. If the end user has access to an interactive service platform like Total Connect 2.0 or Alarm.com, then they can receive text and/or email alerts regarding any alarm events. The system will alert the alarm reporting service, and the reporting service will forward the notification to TC2 or ADC. From there, TC2 or ADC will alert the end user. If the end user has self-monitoring only, then it will be up to them to contact the necessary authorities. Self-monitored users will not receive automatic dispatch from a central station.