The Oracle® Enterprise Session Border Controller (Enterprise SBC) uses the Digium Asterisk Hardware Device Interface (DAHDI) to support Time Division Multiplexing (TDM) operations. In certain situations, the DAHDI requires a restart to apply changes to any tdm-config, tdm-profile, fxo-profile, or fso-profile configuration parameter that the system cannot update by simply reloading the configuration. When you attempt to activate configuration changes, the system detects any change that requires a restart and issues the dahdi restart command. Oracle recommends making changes to parameters that require a restart during a maintenance window because the system terminates all active TDM calls during the restart process.