... ,support ITU H.323V4 and IETF SIPV2 2,eight ports SIM VoIP gateway 3,high quality speech ensured ... : 850MHz, 900MHz, 1800MHz, 1900MHz Power: Input AC100V ~ 240V, output DC12V/2A +-10% Power consumption: 32W maximum Network card: 100 ... T x2 LED: Operation and lines light GSM Passway:eight Operating temperature: 10°C to 40°C (32°F ... you are calling with your customer by server eight ports SIM VoIP gateway