Cisco Systems. Implementing Cisco Voice Gateways and Gatekeepers. Volume 2. Student

Cisco Systems, 2006. — 376 pages.Cisco Unified Survivable Remote Site Telephony (SRST) provides Cisco Unified CallManager with fallback support for Cisco IP phones that are attached to your remote networks. Cisco Unified SRST enables routers to provide call-handling support for Cisco IP phones when they lose connection to remote primary, secondary, or tertiary Cisco Unified CallManagers, or when the WAN connection to where the Cisco Unified CallManager is located is down.