GRANDSTREAM  HT841 Voice Gateway 4FXO,1 FXS, 2 Port LAN Gigabit, T.38 Fax, 3 SIP Account 
   Support  4 Analog Trunk Lines and 1 Analog Extension.
 
The HT841 FXO gateway series enables businesses of all sizes to create an easy-to-deploy VoIP solution. These 4-port FXO gateways offer the ability to seamlessly connect multiple locations and all devices within an office to any hosted or on premise IP PBX network to make deployments as easy as possible. The HT841 include FXO and FXS ports to support remote calling to-and-from the PSTN line. Advanced telephony features, easy automated provisioning and superb voice quality allow the HT841 to be the ideal VoIP gateway for business and residential solutions
Supports 3 SIP profiles through 1 FXS port and 4 (HT841) FXO ports
Built-in performance NAT router
Lifeline support to protect against power outages (FXS port is hard-relayed to the FXO port)
3-way voice conferencing per port
Automated and secure provisioning options using TR069
Supports T.38 Fax for reliable fax-over-IP
Failover SIP server automatically switches to the secondary server if the main server loses connection
AES encryption with unique security certificate per unit provides powerful security protection
Warranty :   Limited Lifetime