>Dual path communicatio of alarm events and other signals over LAN, PSTN,
  Wi-Fi (-W model), GPRS and 3G/4G utilizin amain and backup channel with
  configuable priority
>4/8 on-board wired zones, and expandable with up to 20/64 wired zones
> Up to 16/56 wireless inputs, 18/60 wireless outputs, 8 keyfobs, 1 wired
  siren and 2 wireless sirens
> Camera accessing (only supported by DS-PHAXX-W2/4)
> Pre-alarm (5 s) and post-alarm (2 s) recording for video verifiatio to the
  alarm receiving email or  mobile client
> Uploads alarm events to alarm receiving center or platform
> Supports arming/disarming via keypad, mobile client, iVMS-4200, SMS,
  and tag  
> Configuatio via web client, Hik-Connect, or iVMS-4200
> Pushes alarm notifatio via messages and email
> AES-128-bit data encryptio 
> LED indicator for indicatin system status 
> Expandable PSTN, 3G/4G, and GPRS interface 
> Supports RS-485 input and output expander 
> Supports lithium battey (-P model) or storage battey (-M model)
> 1 manufacturer, 1 installer, 1 administrator, and 13 users (DS-PHA20)/
 45 users (DS-PHA64)