What you need is a SIMCard which supports Call ID function.
Functions & Features of the GSM Alarm System:
1. GSM Frequency: Dual-Band(900/1800MHz), Quad-Band is optional(850/900/1800/1900Mhz) ;
2. Supports armed, disarmed by SMS or remote control or telephone;
3. Supports start or stop the siren by telephone or SMS command;
4. Supports Swith On or Off the output relay by telephone or SMS command;
5. Automaticed send SMS Alert and dial to the pre-set cellphone when any sensor triggered;
6. Equips with 2 Wired Zones,NC/NO, and Zone Name is editable;
7. Equips with 8 Wireless Zones, Zone Name is editable;
8. Supports 3 SMS alarm cellphones and 5 dial alarm telephone numbers;
9. Equips with 1 relay output, it likes a switch, use for driving DVR, light, gate or other electric appliances once the system activated;
10. Reserved 12VDC power source from the control unit for wired sensors;
11. Supports external power failure&recovery alert function;
12. Supports wiretap through internal Mircophone;
13. Supports wired and wireless siren;
14. Supports alert user by SMS when the remote control has been used to control the system; this function can enable or disable by user;
15. Standby internal rechargeable battery which can last 12 hours;
16. Based on the GSM communication network and Voice Operation Menu technology, apply to wide range situations;