VaxVoIP SIP SDK accelerates the development of SIP based webphone, softphone and IVR systems for Desktop OS and Mobile-Phones. VOICE CHANGER SUPPORT: VaxVoIP SIP SDK supports Voice Changer, which works in real-time and let you sound like a robot, a chipmunk, a drunk grandpa, a teen boy or someone who just inhaled helium. ANSWERING MACHINE DETECTION SUPPORT: VaxVoIP SIP SDK exports functionality to develop interactive intelligence based answering machine detection feature. IE, FIREFOX, GOOGLE CHROME, SAFARI AND OTHER WEB BROWSERS SUPPORT: Webphone developed by VaxVoIP SIP SDK works with the latest versions of almost all web browsers like: Microsoft's Internet Explorer, Fire Fox, Google Chrome, Safari and other Mozilla based web browsers. DEVELOP SOFTPHONE FOR POCKET PC, iPHONE, iPAD, iPOD & HAND-HELD DEVICES : It is really easy to develop softphone for MS Windows Mobile based Pocket PCs (HTC, i-Mate, XPERIA etc.), Apple iOS based devices (iPhone, iPad, iPod etc.) and other Hand-Held device. DEVELOP SIP BASED INSTANT MESSENGER: One can easily add SIP based Instant Messiging and Presence feature in its VaxVoIP integrated softphone. MULTI-PARTY VOICE CONFERENCE: User can dial and receive multiple calls to start conference call. ACOUSTIC ECHO & NOISE CANCELLATION OR SUPPRESSION: In order to eliminate the acoustic feedback and produce high quality of output speech, an echo & noise canceller is introduced in the VaxVoIP SIP SDK. RECORD CONVERSATION INTO WAVE (.WAV) FILE: During the phone call, you will be able to record the conversation into wave (.wav) file for later play back. CALL FORWARDING: Forward an incoming call to other phone number, user name or sip account. CALL TRANSFER: Transfer a call to other phone number, user name, sip account or sip uri.