VoIP SIP SDK helps you turn your mobile phone into a voip phone that can be used to dial and receive phone calls. VoIP SIP SDK can be customized in a variety of technical ways and includes features like DTMF, STUN support, SIP activeX control, Dynamically loadable codecs, IM interface, Adaptive silence detection, and quite a few more. The user interface is totally customizable as well, so you can add your branding there and make sure it looks good. VoIP SIP SDK promises high quality audio on the calls, and it can work with firewalls and NATs without a problem. Overall, it's compatible with Asterisk, OpenSER, and any other products based on open standards. This program is useful for businesses who need to brand a voip solution for phones, but as it is really customizable, it likely requires some technical expertise to get it working for you. Overall, VoIP SIP SDK is recommended for anyone with expertise at hand and a need for the program.