Is it possible to connect Axon to ISDN lines through an ISDN board and using TAPI?

You will probably be able to do this with an ISDN gateway device - please see on the VoIPtalk website for more information.

Unfortunately we cannot provide any further information or support on this issue because we do not have any ISDN lines here and have not tested Axon with any ISDN gateway hardware (We would appreciate any feedback that you are willing to provide which may benefit other people enquiring about this capability in Axon).