This read-only Counter32 counts NTFY (Notify) messages sent to the call agent for which a failure return code was received or which timed out waiting for a response. An admin cares because a failed notify means an observed event, like a DTMF digit, was not successfully reported to the call agent, potentially breaking IVR or feature logic that depends on it. For example, an operator seeing IVR menu navigation problems would check this counter for elevated failures suggesting notify messages aren't reaching the call agent.