... good technical support 1. PC-to-PC and PC-to-phone operation; 2. USB1.0 & 2.0 Compatible; 3. No sound ... , MGCP, SIP protocol; 6. Echo cancellation, noise reduction; 7. Support Skype, UUcall, Alt, QQ, MSN, Talk, Yahoo, Sip Discount, X-Lite ... RAIDER, VoipWise Onet2phone; 8. Full duplex communication; 9. Support Skype speed-dialing function; 10. Key-in tone function. WIDETELL USB VOIP PHONE 110B