... Support RFC2833 and Redundant RFC2833,distinctive ringing,MD5 authentication,call forwarding,call waiting, telephone hot lines, alarm clock, speed dial ... other value-added services RFC2833, distinctive ringing, MD5 authentication, call forwarding, call waiting, telephone hot lines, alarm clock, speed dial ... -way calling support local mixingl 7×24 Hours call loss≤0.01%l Support POTS GR909 lines test ...