VoIP SIP SDK – changelog

Please have a look at changelog for all versions of VoIP SIP SDK for Windows:

VoIP SIP SDK – Recent changes:


  • Added ability to set CallInviteTimer. Default value is equal to 40 seconds.
  • Disabled playing local dial tones to remote side.
  • Added ability to handle “Registration removed” event.
  • Additional fix of ’183+SDP’ message handling.
  • Added SRTP support.
  • Updated help documentation.
  • Redesigned code that checks RTP port range availability.
  • Added new codecs codec_amrwb.dll and codec_amrnb.dll.
  • Added ability to send/receive text messages to all examples.
  • Redesigned example with right sound options name (echo, noise, autogain).
  • Fixed bug with Hold/Retrieve conference call.
  • Modified code that handles receiving UPDATE sip message.
  • Added ‘UseMixerPlayer’ setting.
  • Removed previous changes, the SDK plays files depending on this option.
  • Modified code that handles receiving messages 180 Ringing with enabled 100rel.
  • Added ability to send PRACK answer.


  • Added ability store ini file in utf-16 format, load/store ini files from “Settings” form
  • Improved applying new settings procedure. It allows avoid bugs with changing registration/network settings in runtime
  • Added new example MlSampleSkinCPP, Allows create and apply new skins without changing source code, like Winamp
  • Added ‘AutoAnswer’ feature
  • Automatic discovering available network interfaces and selecting better to reach registrar server.
  • Manual selection of network interface for RTP data exchange.
  • Redesigned STUN feature
  • Added feature to detect availability SIP/RTP ports
  • Added ability to send/receive text messages
  • Added fax tone detection
  • Added ability to display CallerId in generated events
  • Added ability to display call duration
  • Added ability to change network interface to VB6, VB.NET examples
  • Added ability store ini file in utf-16 format
  • Renamed to “ABTO SIP SDK”
  • Added ability load/store ini files from “Setting” dialog in MlSampleWindowCpp
  • Redesigned changing settings procedure. It allows avoid bugs with changing registartration/netowork settings in runtime
  • Added new example MlSampleSkinCPP
  • Added ability to set network interface to CS and Delphi examples
  • ‘Run now’ options starts new exmaple MlSampleSkinCPP
  • Added ‘AutoAnswer’ feature
  • Fixed Ml-VB6 example bug with renamed dll
  • Fixed bug in condition that checks is open SIP port.
  • Added ability to change network interface to VB6, VB.NET examples
  • Component use first found IP V4 by default
  • Manual network interface selection
  • New examples: 1. “MlSampleGSMGateway” that allows route incoming calls to GSM phone though bluetooth
    2. “MlSampleOperator” Can be used as call center operator terminal. Made as auto-answer phone Allows for manager connect to operator and listen conversation
  • AuthID handling
  • New config variable “LocalIP”
  • Explicit multilines handling added
  • Conferences quality issues fixed
  • Configuation handling enhanced
  • Stability has been greatly improved
  • New samples added
  • Help updated
  • Samples updated


  • Added FrameReceived event
  • Saving codec checked state when changing codec order
  • Added .Net wrapper
  • Added C++ Windowless Sample.
  • Help updated
  • Samples updated
  • Added DLL only version, along with ActiveX
  • C# sample for DLL version
  • C# Console version updated
  • C++ application update
  • SDP updates
  • Conference calls updated
  • Caller-id and user-agent customization
  • Retrieving external IP addres from STUN server
  • IM interface added
  • fixed issue with RFC4566
  • Codec disabling
  • Help updated
  • Samples updated
  • Playback of different formats of WAV files
  • Software volume control
  • Noise reduction
  • Auto gain
  • Added local number parameter
  • Help updated
  • Jitter buffer parameters
  • Samples updated
  • Windowless samples on C++ and .NET


  • FAX recognition
  • Conference support introduced
  • Added new VC6 sample
  • Samples updated
  • fixed STUN support
  • added support of Authorization Id
  • Mute Sound
  • VPN support
  • Fixed VB6 compilation issue
  • Call transfer support
  • Added status code on call reject
  • Added Unauthorized and Trying events for user registration
  • Fixed bug with default sound device
  • Fixed to be recognized as valid ActiveX component
  • Samples updated
  • Added Hold/Retrieve
  • Added Record conversation into WAV
  • Delphi sample updated
  • VB sample updated
  • HTML Javascript sample updated
  • Extended OnIncomingCall event arguments
  • Added abitility to play wav files into conversation
  • New event OnPlayFinished to know when play is finished



Development Environments:

  • Visual C++ / C++ / C# .NET
  • VB.NET / VB 6.0
  • Java
  • JavaScript / HTML / HTML5
  • Flash
  • Borland Delphi

Company details:

ABTO Software is the only owner and distributor of VoIP SIP SDK. The company also develops other products and offers software development services. Read more on