/mcpThe FALLBACK_AFTER, SCHEDULED_FALLBACK, and FALLBACK_EVERY parameters are applicable only after you pass the CTI3_TYPE parameter. By default, fallback is disabled. If you enter invalid values for the FALLBACK_AFTER, SCHEDULED_FALLBACK, and FALLBACK_EVERY parameters, the Cisco TSP installation still continues, but the fallback remains disabled. However, when you check the install logs, you can find traces that indicate that the value or values provided were invalid. When you pass two, or all the three fallback parameters (that is, FALLBACK_AFTER, SCHEDULED_FALLBACK, and FALLBACK_EVERY), they are considered in the following order of preference: • FALLBACK_EVERY—First preference • FALLBACK_AFTER—Second preference • SCHEDULED_FALLBACK—Last preference Note Table 5: New Silent Install Parameters Valid values Comment Name All CTI Manager 3 IP address CTI3 "NONE", "IPV4", "IPV6", "HOST" None, Ipv4, Ipv6, or hostname CTI3_TYPE 1-3600 Duration for fallback in minutes. FALLBACK_AFTER The format is YYYY/MM/DD HH:MM. Schedules a time for the initiation of fallback. SCHEDULED_FALLBACK The format is either ddd HH:MM or HH:MM. Schedules a planned fallback. FALLBACK_EVERY From Release 15SU4 onwards, during silent installation, the TSP installer does not perform a robust validation to detect an existing Microsoft Visual C++ 2015-2022 redistributable installed. It may attempt a forced reinstall or upgrade that may result in installation failure. To avoid this issue, users should either uninstall the existing Visual C++ 2015-2022 redistributable before performing a silent installation, or use the GUI-based installer. Important Upgrading Unified CM TSP Client to Release 8.5(1) or Later Using Silent Installation After the silent fresh installation or silent upgrade from previous versions of TSP to the 8.5(1) client, you must reboot the system for the changes to take effect. Cisco Unified TAPI Developers Guide for Cisco Unified Communications Manager, Release 15 and SUs 124 Cisco Unified TAPI Installation Upgrading Unified CM TSP Client to Release 8.5(1) or Later Using Silent Installation