====== Domovní zvonky přes VoIP ======

http://www.2n.cz/cz/produkty/interkomove-systemy/ip-interkomy/helios-ip-verso/

http://www.aliexpress.com/item/Free-shipping-1pc-13-56Mhz-RFID-Reader-USB-Proximity-Sensor-Smart-Card-Reader-2-Pcs-13/32277332266.html

http://www.aliexpress.com/item/Free-shipping-1pc-13-56Mhz-RFID-Reader-USB-Proximity-Sensor-Smart-Card-Reader-2-Pcs-13/32277332266.html

http://www.grandstream.com/sites/default/files/Resources/gxw42xx_usermanual_english.pdf