Desktop softphone development
CROSS • PLATFORM • SOFTPHONE • DEVELOPMENT
Easy SIP integration for VoIP softphone development
VaxVoIP SIP Phone SDK makes it easy to build SIP-based VoIP softphones. Develop your own branded softphone with a custom GUI and full control over features.
✓ Windows, Android, iPhone and iPad
✓ Multiple SIP accounts and lines
✓ Voice, video, messaging and presence
✓ Fully functional 30-day trial
Mobile SIP phone applications
iPhone and iPad softphones
Fully functional evaluation
DEVELOP • A • SIP • SOFTPHONE
Accelerate development with samples and a flexible SDK
Download easy-to-understand sample code to speed up softphone development and simplify SIP integration. Create applications for Microsoft Windows, Android, iPhone, iPad and other supported devices using one product family.
Browse sample source code →
VaxPhone SDK
Cross-platform SIP Phone
Microsoft WindowsDesktop OS
Apple iOSiPhone & iPad
Android OSMobile Devices
SIP Server & IP-PBXBusiness Telephony
IP-Telephony Service ProviderSIP Trunks & Services
FEATURES
Build a complete branded SIP softphone
Use the SDK to create desktop and mobile calling applications with advanced media, call control, messaging and automation features.
Multiple SIP accounts
Add, manage and use multiple SIP accounts within one softphone application.
Windows, Android and iOS
Develop softphones for Windows desktop, Android devices, iPhone and iPad.
Make and receive calls
Connect with SIP servers, gateways and IP Telephony Service Providers.
Multiple call lines
Handle multiple simultaneous calls using built-in multi-line support.
Audio codecs
Support for G.711u, G.711a, GSM 6.10, iLBC and G.729.
Audio conferencing
Initiate and accept multiple calls to create user-side conferences.
Video conferencing
Activate SIP-based video conference features through exported functions.
Hold, transfer and forwarding
Send SIP hold, transfer and forwarding requests to the server.
Messaging and presence
Use SIP SIMPLE for chat and online, offline, away and on-call presence states.
Echo cancellation and AGC
Improve voice quality with acoustic echo cancellation and automatic gain control.
Jitter buffer and PLC
Maintain clear audio during network variation and packet loss.
Call recording
Record phone conversations and save them as standard WAV files.
Play WAV files
Play prompts and prerecorded messages to the remote party during calls.
NAT keep-alive
Keep network ports active through NAT and firewall environments.
Voice changer
Apply real-time robot, chipmunk, teen-boy and helium-style effects.
Answering machine detection
Develop auto dialers that detect answering machines intelligently.
Do Not Disturb
Provide a DND mode that blocks incoming calls when required.
SIPREC client support
Connect the softphone as a SIPREC client to compatible recording servers.
USE • CASES
Create communication applications for multiple markets
Branded Softphones
Deliver your own desktop and mobile SIP phone under your company identity.
Call-Center Agent Apps
Build multi-line agent applications with monitoring and live coaching.
Auto Dialers
Create outbound applications with answering-machine detection.
Unified Communications
Combine voice, video, chat, presence and contact-management features.
Mobile VoIP
Develop Android and iOS applications connected to SIP infrastructure.
ITSP Applications
Offer customer softphones connected to SIP accounts and hosted services.
Recorded Communications
Build applications that save calls locally or connect to SIPREC servers.
Custom Business Apps
Add SIP calling and media capabilities to existing software products.
DEMO • APPLICATIONS
Try VaxVoIP softphones on desktop and mobile
Evaluate ready-to-use applications for Microsoft Windows, Android and Apple iOS before integrating the SDK.
Windows Softphone
Desktop demo application for Microsoft Windows.
Download AppAndroid Softphone
Mobile demo available through the Google Play Store.
Google PlayiPhone and iPad
Apple iOS demo application for supported devices.
Apple App StoreDOCUMENTATION
Documentation for every supported platform
Microsoft Windows SDK
Technical documentation and API guidance for desktop development.
Android SDK
Development documentation for Android SIP phone applications.
Apple iOS SDK
Documentation for iPhone and iPad softphone projects.
License Activation MS Windows SDK
Instructions for activating and managing the Windows SDK license key.
License Activation Android SDK
Instructions for activating and managing the Android SDK license key.
License Activation iOS SDK
Instructions for activating and managing the iOS SDK license key.
SAMPLE • SOURCE • CODE
Begin with working projects for desktop and mobile
Download any sample project and evaluate it with the fully functional 30-day trial. Review its ReadMe.txt file for setup instructions and use the technical manual for details about calling, registration, media and user-interface workflows.
Microsoft Windows Desktop
Visual C# .NETRegister SIP accounts and manage voice calls from a Windows C# softphone.
Visual Basic .NETHandle incoming calls, media and account events in a VB.NET desktop app.
Visual C# .NET (WPF)Build a responsive WPF softphone interface with C# call controls.
Visual Basic .NET (WPF)Create a WPF-based SIP phone interface using Visual Basic .NET.
Visual C++Add native SIP calling, audio and call-state handling with Visual C++.
DelphiDevelop a Windows Delphi softphone with registration and call management.
Android
JavaBuild an Android SIP phone with Java registration and mobile call controls.
Apple iOS
Objective-CIntegrate SIP registration and voice calling into an Objective-C iOS app.
SwiftCreate a native Swift softphone for iPhone and iPad communication.
DOWNLOAD • SIP • SDK
Start your fully functional 30-day trial
Choose the VaxVoIP SIP Phone SDK package for your target operating system.
Version 8.6
Microsoft Windows SIP Phone SDK.
Download NowVersion 8.4
Android SIP Phone SDK.
Download NowVersion 8.4
iPhone and iPad SIP Phone SDK.
Download NowFREQUENTLY • ASKED • QUESTIONS
Answers before you start building
Find practical answers about softphone development, supported platforms, SIP features and licensing.
How can I get a 30-day free trial?
Download a demo application, SDK package or sample source code and evaluate it for up to 30 days.
How do I develop a softphone?
Start with the supplied sample source code and demo applications, then use the technical manual for details about exported functions, events and implementation workflows.
Can I develop an auto dialer with answering machine detection?
Yes. VaxVoIP SIP Phone SDK includes answering-machine detection for automated calling applications.
Can I connect to an ITSP to make and receive calls?
Yes. Use a SIP account from an Internet Telephony Service Provider to place and receive calls.
Can I develop live call coaching?
Yes. Multi-line support can be used for user-side coaching where a supervisor guides an agent without the customer hearing.
Is SIPREC call recording supported?
Yes. The SIP Phone SDK can operate as a SIPREC client with compatible SIPREC recording servers.
Does it work with Asterisk?
Yes. The SDK works with Asterisk and other standards-based SIP servers and service providers.
Can VaxVoIP customize the SDK for our needs?
Yes. Customization services are available for specific product and integration requirements.
Is the SIP Phone SDK source code available?
Yes. The SDK source code can be provided with user rights, and source-code training can also be arranged.
ANNUAL • COMMERCIAL • LICENSING
Choose the platform you need
Annual licenses include technical assistance, updates, new releases, ongoing maintenance and issue resolution.
Microsoft Windows
$2,640
One year · single software licenseContact SalesAndroid
$2,840
One year · single software licenseContact SalesApple iOS
$2,860
One year · single software licenseContact SalesBUILD • YOUR • OWN • SOFTPHONE
Ready to create your next SIP phone application?
Download the SDK, review the samples and discuss platform licensing or customization requirements with the VaxVoIP team.