...Features include conferencing, call hold, transfer and forwarding, WAV call recording, SIPREC client support, echo cancellation, jitter buffering, and answering-machine detection. Sample projects cover C#, VB.NET, WPF, Visual C++, Delphi, Java, Objective-C, and Swift, with platform-specific documentation. The SDK connects applications to standards-based SIP servers, IP-PBX systems, gateways, and telephony providers. Use cases include softphones, mobile VoIP apps, call-center tools, auto-dialers, and embedded business communications. A fully functional 30-day trial is available; annual licenses are sold separately for Windows, Android, and iOS.