Voice Register Global Mode Srst __top__ Jun 2026

The command voice register global followed by mode srst is a foundational configuration used in Cisco Unified Communications Manager Express (CME) and Survivable Remote Site Telephony (SRST) environments. It establishes how a router handles IP phone registration during a WAN failure. Defining Global SRST Mode

📌 The mode srst command enables a "hands-off" failover. No manual intervention is required from IT staff to restore dial tone during an outage. voice register global mode srst

The command enters the configuration mode for SIP SRST parameters, and the sub-command mode srst explicitly tells the Cisco IOS router to treat this configuration block as a fallback service for SIP endpoints, rather than a standalone CME (Communications Manager Express) system. The command voice register global followed by mode