If the calling/called phone number is stored in Microsoft Dynamics CRM, then the number should be resolved to the corresponded CRM record. If the number does not resolve, make sure that the number is stored in the "MSCRM-ADDONS.com CTI CallInfos" entity. 

CTI 2011 TAPI wrapper needs a TAPI driver that is suitable to your Phone PBX server.

Each PBX phone-system vendor has its own TAPI driver.

Our TAPI wrapper has not an active role on the TAPI lines, it is just a passive listener to random TAPI driver events and eventually, it triggers them in case of outgoing calls, accepting the incoming offers.

If you outgoing calls are successful when made from CTI client, but not from the CRM entity, simply check the Internet Explorer Security Options. Please make sure that your CRM Server is included in the Trusted Sites Zone.

Before an entity or PhoneCall activity can be opened by an incoming/outgoing phone call, the phonenumber must be resolved.

The CTI supports only one call at the moment.

However, when transferring existing calls to a third party, it can happen that some sessions are not correctly closed. You can compare that with a broken Lync conversation.

The fields.xml Settings are server-side CRM Settings.