Ozeki SIP .Net SDK to develop auto answering C# VoIP softphone to auto answer incoming calls. The program registers to a SIP PBX and waits for incoming calls to accept. Auto answer can be a previously captured audio file or a text message that is read up by the VoIP client. It is based on Ozeki VoIP SIP SDK that ensures excellent VOIP PBX compatibility (like 3CX, Asterisk, Cisco UCM, etc.) and online VoIP service provider (Skype Connect, Gafachi, etc.) support, multiple calls and lines. The softphone can be customized with further features to functioning as a full softphone and with company logo. The basic idea behind this program is that when there is an incoming call, it is automatically accepted but instead of speaking to the caller, the caller listens to a message played into the call. The program can only register to a PBX with the specified SIP account and it waits for an incoming call to accept. When there is an incoming call the softphone accepts it and the communication can be started.
The GUI of the example program is really simple, it only contains the PBX registration form, some notification labels and a button that can be used for ending the call. As this is an auto-answering softphone you cannot cancel the call or in this case you cannot even start a call with it. The actual difference between a normal softphone and this application is that when an incoming call comes the call is accepted without waiting for a user interaction.
Ozeki SIP SDK ensures the follows: CODECS: G.711 aLaw/uLaw, G.729, iLBC, GSM, G.722, SPEEX, SPEEX-WB, L16, G723, G726-16, G726-24, G726-32, G726-40, G728. Tools: SIP protocol implementation, RTP implementation, RTCP implementation, Audio device support (mic, speaker), Audio encoding / decoding (audio codecs), Voice quality improvement tools (AEC, AVG, NR, Jitter buffer), Video device support (camera and playback), Video encoding / decoding (video codecs), Implemented network communication protocols: UDP, TCP; STUN, TURN support
PC, .NET compatible Development Kit, minimum .Net 3.5. SP1, SIP account