Asterisk can write configuration data to and load configuration data from a database using the external configuration engine (also known as realtime). This enables you to map external configuration files (static mappings) to a database, allowing the information to be retrieved from the database. It also allows you to map special runtime entries that permit the dynamic creation and loading of objects, entities, peers, and so on without a reload. These mappings are assigned and configured in the extconfig.conf file, which is used by both res_odbc and realtime.