26. Added audio related commands: AT+QWDTMF (Chapter 12.15), AT+QAUDRD, AT+QPSND, AT+QTTS, AT+QTTSETUP, AT+QWTTS, AT+QAUDCFG, AT+QAUDPLAY, AT+QAUDPLAYGAIN, AT+QAUDRDGAIN, AT+QACDBLOAD, AT+QACDBREAD and AT+QACDBDEL (Chapter 12.17–12.28). 27. Added SSL related AT commands...