AddTapi.NET CTI Computer Telephony


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We provide free basic technical support via email. We try to answer all emails within 1-2 business days.

Consulting Services

If you need help integrating AddTapi.NET into your application or have a project we can help you with, please make sure to check our Consulting Services. We offer full range of services from simple code reviews to full-cycle application design, development and integration.


Frequently Asked Questions

Professional and Enterprise versions have the same set of features but Professional version is limited to 2 lines/extensions per computer. Line in TAPI is a single phone line or phone extension. Typical desktop application is installed on each user's desktop and works with a single line object representing that user's phone line/extension. For such applications Professional version is sufficient. Enterprise version is needed if your application runs on a server and monitors or controls several lines/extensions. For example, you will need the Enterprise version if you are developing an IVR system that answers incoming calls on multiple lines, or a call distribution system that sends incoming calls to different extensions.

AddTapi.NET works with many TAPI-compatible PBXs or phone systems from Cisco, Avaya, Panasonic, NEC, 3Com, Nortel, Allworx, Siemens without any additional hardware. You will need a TAPI-compatible computer telephony device if you want to work with analog or digital phone lines directly without a PBX.

We offer professional quality TAPI-compatible USB CTI devices that work with regular analog (POTS) phone lines. You can also connect our device to a VoIP adapter or SIP gateway. Our CTI devices are 100% compatible with AddTapi.NET and other TAPI software and offer high reliability and excellent feature set in a compact form factor.

For large multi-line deployments we recommend Dialogic Diva telephony boards. Dialogic makes telephony boards for 2, 4 and 8 analog lines as well as multi-channel boards for E1/T1 or ISDN digital lines. Please tell us about your requirements and we will help you with hardware selection.

You have to install Cisco Telephony Service Provider (Cisco TSP) on the computer where AddTapi.NET and the applications that use it are installed. Cisco TSP version should match the version of the Cisco UCM system that you are using. Cisco TSP can be downloaded directly from the Cisco UCM system. Open Cisco UCM web-based administration panel, select Application -> Plug-ins in the menu and you will see Cisco Telephony Service Provider. Download, install and configure Cisco TSP then restart your computer. After that AddTapi.NET and other TAPI-compatible applications will be able to access your Cisco UCM system.

AddTapi.NET works with Avaya IP Office / Avaya Aura and we have many customers who use AddTapi with Avaya phone systems. You will need to install and configure TAPI driver (also called Telephony Service Provider or TSP) for Avaya IP Office / Avaya Aura on the computer where AddTapi.NET is running. TSP for Avaya phone systems is called Avaya TAPI Link and is included in Avaya CTI Link installation. You should have it on CD that came with your IP Office or Aura system.

Avaya CTI Link Lite is free but it can monitor/control only one line/extension per PC. Avaya CTI Link Pro is needed for server-based applications that work with all available lines/extensions. CTI Link Pro license can be purchased from your Avaya supplier.

Panasonic KX-TDA, KX-TDE, KX-NS1000 series PBX support TAPI and work well with AddTapi.NET. You will have to install and configure TAPI driver (also called Telephony Service Provider or TSP) for your Panasonic PBX on the computer where AddTapi.NET is installed. Panasonic TSP is provided free of charge. You can obtain it from your Panasonic supplier or download it from this page .

Please download and read TSP Installation Manual from that page. In most cases you do not need any additional hardware and the TSP can access your Panasonic PBX over the network. Some models like Panasonic KX-TDA 100 require a CTI Link Card in the PBX to enable TAPI support.

Restart your computer after Panasonic TSP is installed and configured. After that AddTapi.NET and other TAPI-compatible programs will be able to access your Panasonic PBX.

All models of analog and digital Dialogic Diva telephony boards supports TAPI and work very well with AddTapi.NET. Please start Diva Configuration Manager and enable TAPI service for the board. To add TAPI service to the configuration, click Insert in the menu bar and select the service you want to add. Connect your Diva Media Board to the TAPI icon to make the TAPI interface available. To do so, right-click the board icon, hold down the mouse button and move the cursor to the TAPI icon. Release the mouse button. Final configuration should look similar to the configuration in the screenshot below:

Dialogic Diva Configuration

If you have any problems with outgoing audio, please switch Voice Coding from Protocol Default to Force u-Law as shown on the screenshot.

Yes, AddTapi.NET supports NEC UNIVERGE SV8000 and SV9000 series. You have to install TAPI driver, also called Telephony Service Provider or TSP, on the computer where AddTapi.NET is installed. NEC provides 1st party and 3rd party TAPI drivers. If your application is installed on each workstation and monitors a single user line/extension (one line/extension per PC), you need a 1st party driver. Please contact your NEC supplier to obtain NEC CTI license and TSP for your NEC phone system.

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