CTI DevLink

Last Updated : Feb 21, 2023 |

DevLink is an historical telephone API used by 3rd-party Windows applications to interface with IP Office systems. It uses a Windows DevLink DLL file to connect to the IP Office system using the system's system password. This interface is supported up to IP Office Release 9.1.

DevLink3 is a enhanced telephony API available for 3rd-party applications to interface with IP Office 10 and higher systems. It is an operating system independent interface which, unlike the previous DevLink API, no longer requires the use of a specific Windows DLL file provided by Avaya. Full documentation for DevLink3 and example files are available as an SDK from Avaya DevConnect.

This manual covers a sub-set API provided within DevLink3 to support existing pre-Release 10 DevLink applications to still run with IP Office systems upgraded to IP Office Release 10 and higher. Throughout this manual the term "legacy application" is used for such applications.

Use of both DevLink3 and legacy DevLink applications requires the IP Office system configuration to contain a CTI Link Pro license.

Changes Required to Support Legacy Applications

The follow changes to both the IP Office system configuration and the DevLink application are need for the legacy application to connect to an IP Office Release 10 or higher system.

  1. Change the IP Office Security Settings – DevLink3 makes use of the enhanced security applied to all connections to IP Office systems. This requires creation of a specific service user and rights group in the IP Office security configuration.

  2. Update the Application Operation – The following changes to the operation of the legacy application are required:

    1. Replace the Existing DevLink DLL – Legacy applications use a Windows specific DevLink DLL file. To support operation with IP Office Release 10, this original DLL needs to be replaced with a new DevLink3 DLL file. The DEVLink3 SDK includes separate DLL files for 32-bit and 64-bit applications.

    2. Install the Microsoft DSS Cryptographic Provider – The username/password is authenticated using SHA1 and the Microsoft DSS Cryptographic Provider. This requires the provider to be installed on the Windows PC running the application. Refer to https://msdn.microsoft.com/en-us/library/windows/desktop/aa386985(v=vs.85).aspx.

    3. Connection Password – Previously applications connected to the IP Office using the system password. The security changes above require applications to now connect using the password set for the new DevlinkDLL service user.

    4. Connection Address – Previously applications could connect to an IP Office using the broadcast address 255.255.255.255. The security enhancements require applications, including legacy applications, to connect using the specific IP address of the IP Office system.