When Cisco converted to an IP telephony network and exchanged its time-division multiplexing-based PBX Switches for Cisco CallManager clusters, the company’s mission-critical Operations Command Center (OCC) was reluctant to make the change at that time. This small group facilitates problem resolution for significant corporate wide failures that could affect global business continuity. Over time, IP telephony was proving to be a remarkably reliable architecture for voice, but the OCC could not risk a moment of down time
Through demonstrations and statistical evidence, Cisco IT determined that the best solution for ensuring continuous availability of the IP telephony system was a redundant architecture based on Cisco Survivable Remote Site (SRS) Telephony, a feature of the Cisco IOS Software. SRS Telephony automatically detects a failure in the network, and then uses Cisco Simple Network Automated Provisioning (SNAP) capability to initiate a process to intelligently auto configure the router to provide call-processing backup redundancy for IP phones.
In its usual role, SRS Telephony is used in branch offices so that employees can continue to place and receive calls in the event of a WAN link outage between their office and a centralized Cisco CallManager cluster in a different location. The OCC, in contrast, uses SRS Telephony in the same location as the CallManager cluster, to give IP phones a redundant level of service to survive unplanned technical or security incidents.
The OCC now has the confidence that its IP telephony network will continue to operate even if the general Cisco network should experience problems. "When all else fails, our telephony system must work," says Ian Reddy, IT Project Manager for the IT Operations Command Center. "It's a very positive statement about IP telephony in general and SRS Telephony in particular that our group made the transition."
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Cisco Unified Survivable Remote Site Telephony Case Study
Cisco Unified Survivable Remote Site Telephony Solution