: The 11.1 Manager can manage older systems, but older Manager versions are not compatible with 11.1 systems. Installation Steps
: Enhanced encryption, certificate management, and SRTP support.
: The most reliable source is the Avaya Support Site . Log in with your credentials. Search for "IP Office" in the product name box. Select release 11.1 from the drop-down menu. Locate the "IP Office Administration Suite" ZIP file.
Once you have obtained the verified setup.exe or ZIP file, follow these steps for a clean installation: Downloading the Software - Avaya Documentation