SRST fallback is a software feature embedded within Cisco IOS routers. Under normal conditions, IP phones at a remote site register with a central CUCM cluster over a Wide Area Network (WAN). However, if that WAN link fails or the CUCM becomes unreachable, the phones lose their "brain."
is a Cisco feature that provides call-handling redundancy for branch offices when their connection to the central Cisco Unified Communications Manager (CUCM) is lost. Core Components srst fallback
: Go to System > SRST and add the router's IP address. SRST fallback is a software feature embedded within
Therefore, SRST fallback is typically a in debugger settings (e.g., "Connect: under reset" vs. "normal") rather than a default behavior. Core Components : Go to System > SRST
For a complete branch redundancy solution, both features are typically configured on the same router. Why Your Business Needs It
Why is SRST fallback necessary? Modern microcontrollers (ARM Cortex-M series, RISC-V, etc.) are complex. Several conditions can prevent a debugger from connecting: