The RT-EIMS3001 is a medium-capacity IP PBX which is designed especially for SMB and branch offices. It provides professional IP telephony services for a maximum of 2, 000 SIP users and 624 analog extensions, 12 E1/T1 ports for digital trunk access and 96 FXO for analog trunks. It adopts high reliable design, including dual main control boards and 1+1 redundancy backup of power supplies. It provides high-quality a maximum 384 channels audio conference and 144 concurrent calls for media resources.