... and PSTN alarm system,gsm pstn system,gsm pstn alarm system,gsm security system GSM and PSTN alarm system,gsm pstn system,gsm pstn alarm system,gsm security ... .l Different zones can dial a pre-set telephone number.l Support ISD automatic voice mailbox for ... length of voice message is 10 seconds.l Telephone (phone) long-distance telephone control for arming, disarming, monitoring, remote announcement ...