VaxTele SIP Server SDK (Software Development Kit) is a complete development toolkit, which allows software vendors and Internet telephony service providers (ITSP) to develop SIP Server and (SIP) Session Initiation Protocol based VoIP systems for Microsoft Windows to install computer to computer voice chat, chat rooms, IVR systems, call center services, calling card services, dial/receive computer to PSTN (Public Switched Telephone Network) and mobile phone calling services.
VaxTele SIP Server SDK supports Component Object Model (COM) based technology and can be incorporated in any Microsoft Windows-based application.
It also includes technical manual, demo SIP Server, and sample codes for C#, Visual C++, Delphi and VB.NET development languages to understand about how to use VaxTele's COM component and accelerates the SIP Server development process.
There are many Internet Telephony Service Providers (ITSP) are available on the internet, who already provide service to dial and receive SIP based phone calls to and from PSTN and mobile networks.
It can connect to those service providers to dial and receive PSTN and mobile (local and long distance) calls.