... - Call Transfer, Call Back on Busy - PAP2T phone adapter The Linksys Phone Adapter enables high-quality feature-rich telephone service through ... Initiation Protocol(SIP) Supports multiple voice compression G.711,G.726,G.729,and G.723.1 Web-based configuration through a built ... Initiation Protocol(SIP v2)Voice Codecs: G.711 a-low G.711u-law,G.726,G.729A,G.723.1Ringer Equivalence Number(REN): 5REN ...