The only VoIP Intercom with SRST Support
Survivable Remote Site Telephony (S.R.S.T) is a Cisco Unified Communications Manager (CUCM) call processing backup mechanism. SRST allows CyberData IP intercoms to register to a Cisco router within a SIP environment. A Cisco router in SRST mode provides call setup and call teardown services similar to CUCM. All CyberData SIP enabled IP Intercoms feature Cisco S.R.S.T. See this Cisco Website page to see what they say about it.
Cisco Unified SRST provides Cisco Unified Call Manager with fallback support for Cisco IP phones and CyberData IP Intercoms. Both are attached to a Cisco router on your local network. Cisco Unified SRST enables routers to provide call-handling support for CyberData IP Intercoms when they lose connection to remote primary, secondary, or tertiary Cisco Unified Call Manager installations or when the WAN connection is down.
Cisco Unified Call Manager supports CyberData IP Intercoms at remote sites attached to Cisco multiservice routers across the WAN. Prior to Cisco Unified SRST, when the WAN connection between a router and the Cisco Unified Call Manager failed or when connectivity with Cisco Unified Call Manager was lost for some reason, Cisco IP phones + CyberData IP Intercom on the network became unusable for the duration of the failure.
Cisco Unified SRST overcomes this problem and ensures that the CyberData IP Intercoms offer continuous (although minimal) service by providing call-handling support for devices directly from the Cisco Unified SRST router. The system automatically detects a failure and uses Simple Network Auto Provisioning (SNAP) technology to autoconfigure the branch office router to provide call processing for Intercoms that are registered with the router. When the WAN link or connection to the primary Cisco Unified CallManager is restored, call handling reverts back to the primary Cisco Unified CallManager.
When CyberData IP Intercoms lose contact with primary, secondary, and tertiary Cisco Unified Call Managers, they must establish a connection to a local Cisco Unified SRST router to sustain the call-processing capability necessary to place and receive calls. The CyberData IP Intercom retains the IP address of the local Cisco Unified SRST router as a default router in the Network Configuration area of the Settings menu. The Settings menu supports a maximum of five default router entries; however, Cisco Unified Call Manager accommodates a maximum of three entries. When a secondary Cisco Unified Call Manager is not available on the network, the local Cisco Unified SRST router’s IP address is retained as the standby connection for Cisco Unified Call Manager during normal operation.