... Support 2 SIP Aaccount 3, Support Transfer calls function/Three-way conference/Call waiting fun Important: It can store ... call to A, and need to talk with Party three, you can press 1# key to call A, ... TX;20,DNS;21,Transfer calls function;22,Three-way conference;23,Call waiting function;24,Call forward ... updates/upgrades;27,Hand-free in a semiduplex way to ensure the talking quality; Two Line VoIP ...