Hi Praveen,
we are a SAP CC (former BCM) partner and focused on telecommunications. Some of our customers are facing the same issue like you to connect existing pbx systems (sometimes heterogeneous systems from different vendors) to SAP CRM/ Contact Center. Thats why we developed an application (SAP CTI middleware) which connects AnyPBX to AnyCRM. That solution features the functionality of the SAP CRM ICI interface, keeps existing IVR scripts and routing algorithms, generates popup screens, synchronizes the present status, connects any contact channel (not just voice) and allows reporting in SAP BW. Let me know if this app. could support you ...
Regards,
Matthias