General rate: Negative
I downloaded and checked this SDK. It seems that they segregated the SDKs based on various fields (SIP Client, Video, EVO, etc.) The online documentation is quite fair and helpful. The greatest problem for me in this SDK is that it does not offer any sample programs however it would be helpful. This is the main reason I search for another SDKs. Currently, I testing Ozeki VoIP SIP SDK (www.voip-sip-sdk.com). They offer one complex SDK to introduce VoIP. Their online documentation is helpful and easy-to-work with. The main factor is the excellent sample programs. Some of the sample programs can be checked at: http://www.voip-sip-sdk.com/p_115-sip-voice-applications-voip.html Both SDKs are royalty fee and at first sight there are no additional fees, however I found the Ozeki licensing more transparent. So, if I consider all the points, I tend to check the Ozeki SIP SDK, because it seems more flexible for me.