Hola,
Para verificar el significado de cada uno de los comandos se puede utilizar la guía de Cisco IOS Voice Command reference y te da explicación de los comandos.
Por ejemplo:
supervisory disconnect dualtone mid-call
supervisory disconnect dualtone {mid-call | pre-connect}
Usage Guidelines
This command configures an FXO voice port to disconnect calls when the router detects call-progress tones from a PBX or the PSTN. Disconnection occurs after the wait-release time specified on the voice port.
Disconnect supervision is automatically enabled in the preconnect mode on the voice port if the supervisory answer dualtone command is entered.
This feature is applicable to analog FXO voice ports with loop-start signaling.
http://www.cisco.com/en/US/docs/ios/12_3t/voice/command/reference/vrht_s12_ps5207_TSD_Products_Command_Reference_Chapter.html#wp1148305
Espero que esto resuelva las dudas.
Saludos,
- Pablo