My customer has 5 sites in five different countries. I just finished the HQ with CCM 5.1 and unity 4.2. The other four sites are Avaya and I am asked to integrate those four sites with HQ in order to by pass the toll for inter sites calls. Could you please let me know what kind of hardware and software do I need to complete this project. Unfortunately, at this moment I don't know anything about the model and the version of the Avaya PBX's. Is there any of them which are not compatible with CCM? Please do not hesitate to refer me to any detailed documents.