Answer: Here’re the details for each command:
AT+CHUP: Disconnect all calls, including voice and data call. But it has no impact on GPRS call.
ATH/ATH0: Disconnect all calls, including voice, data and GPRS calls.
ATH1: Disconnect all calls on ALL MUX channels.
ATH2: Disconnect all data call
ATH3: Disconnect all GPRS call
ATH4: Disconnect all active data/voice call
ATH5: Disconnect all waiting data/voice call
(All calls including all active or waiting voice call, data call and GPRS call)