A VOIP PBX can be connected to CTI Data Connector for Salesforce® with or without a TAPI driver. The TAPI driver is the cost effective solution as it comes often with the telephone system free of charge.
Alternatively you can use:
•specific handsets (supports Windows and MAC)
•SoftPhones with TAPI driver
•If you do not want to install a TAPI driver or you want to use the CTI integration on macOS, the Mondago GoConnect server can be used for some VOIP PBX systems. Alternatively you can use handsets explained in Cloud based PBX
•If your VOIP system does not come with a TAPI driver use one of the options explained in Cloud based PBX