Yealink is supporting OPUS on several other models since firmware V81: Quote: "We will support opus on the standard V81 of SIP-T40P/T23P/T23G/T2 1(P) E2/T19(P) E2." Source: http://forum.yealink.com/forum/showthread.php?tid=29650&pid=51262&mode=threaded I can confirm OPUS implementation on the 'T21P E2' model. -- EL