Ozeki .Net SIP SDK for developing Windows Forms softphone in VB.Net to implement VoIP calls. The sample program allows to make/receive calls, handles DTMF signals to navigate in IVR systems. It is customizable with more features and company logo. It is compatible with most of the PBX systems like Cisco UCM, Asterisk PBX, 3CX Phone Systems and works with VoIP service providers like Skype or Callcentric. It is based on Ozeki SIP SDK that supports multiple simultaneous VoIP phone calls and offers royalty free licensing. Ozeki VoIP SIP SDK is the ultimate tool for software developers to create a Windows Form Softphone in VB.Net. It is based on C#.Net and that is why the integration into any software developed in .Net is really easy and makes the SDK a very versatile tool in the hands of .Net developers. With the help of this SIP SDK VoIP calls can be instantly implemented in any .Net program. The sample program handles outgoing calls, incoming calls, ends a call which is in progress, displays the call status, handles audio data which arrives from the remote end, forwards incoming audio from the microphone to the remote end via the SDK, receives DTMF signals, sends DTMF signals. It handles one telephone line although Ozeki VoIP SIP SDK offers the chance to develop and use multiple telephone line handling simultaneously. Furthermore there are many other functions that can also be implemented just like chat function or call forwarding function. With Ozeki SIP SDK excellent voice quality can be achieved so the Windows Form Softphone in VB.Net sample program is capable to deliver crystal clear sound. This is due to the extended codec support (G.711 aLaw/uLaw, G.729, iLBC, GSM, G.722, SPEEX, SPEEX-WB). After an Ozeki VoIP SIP SDK license has been purchased it is free to use Ozeki VoIP SIP SDK for .Net license with your product and also your product can be freely distributed in as many copies as you wish and there are no royalties or license fees to pay to Ozeki Systems Ltd

Platform:Windows XP

System Requirements: PC, .NET compatible Development Kit, minimum .Net 3.5. SP1, SIP account (or a SIP PBX)