The HT812 VoIP gateway is based on Grandstream’s market-leading SIP gateway technology and can be used in combination with Advisor Advanced. In addition to the alarm reporting to OH-NetRec, adding the HT812 offers a solution where two-way audio verification over VoIP is required. The HT812 is physically installed at the protected site and establishes a connection to a remote SIP server. The solution allows the operator in the central monitoring station to listen into the protected premises and ask any unauthorized person to identify himself in case of an alarm.