Disaster Recovery for Your UC System: Designing Reliability into Your Architecture

As every network administrator knows, life happens. And whether it’s because of a major storm or earthquake or even a minor outage triggered by a downed power line, when the network goes down, a couple of sleepless nights can easily follow. But in an organization that’s invested in mission-critical unified communications (UC) system, when the network goes down, implementing a proven strategy to keep communications lines open and recover quickly is all the more important.

“Organizations need a powerful combination of a reliable distributed architecture that is remotely survivable and, at the same time, easy to manage,” says Rich Winslow, senior sales engineer at ShoreTel.

Reliability, disaster recovery and business continuity are inextricably intertwined, Winslow observes. A system that supports each of these factors—overall reliability that ensures a high level of uptime, a disaster recovery plan that minimizes downtime, and a business-continuity strategy that keeps operations as normal as possible during a minor or major disruption —is key to any organization’s successful UC implementation.

To help organizations ensure high communications availability, the ShoreTel Pure IP Unified Communications solution is designed for exceptional reliability and optimal business continuity. This design includes using the Wind River VxWorks embedded operating system—the same operating system that powers many life-saving devices such as pacemakers and anti-lock brake systems.

“The ShoreTel UC system is designed to be very robust,” Winslow explains. “The only moving part is a fan to cool the inner workings of the PBX. That’s one factor that contributes to the appliance’s mean time between failures of more than 12 years as well as its delivery of more than five-nines of availability to users.”

Minimize Risk of Failure
Using a server to run the PBX typically results in more failures because servers depend on hard disks, which are renowned for reliability issues. However, a hardware platform that is not dependent on spinning media provides exceptional reliability. In the ShoreTel UC system, PBX functionality runs on small, dedicated appliances that provide dial tone independence from other network components.

In addition, some competing systems place numerous functions, including routing, switching, firewall, and PBX, on a single device—a potential case of too many eggs in one basket, since any one failure will impact all other services.

“Disaster-Proof” Architecture
In the event of an outage at one location, the distributed architecture of the ShoreTel UC solution helps ensure that features stay live at the other locations.

“The ShoreTel system is a fully distributed IP UC system with no single point of failure,” Winslow says. “Call control is distributed to intelligent gateways called voice switches. In addition, voice applications, including voicemail and automated attendant, run on standard server hardware from anywhere on your IP network.”

In the event of a wide area network failure, the voice switches, including all the phones and trunks, will continue to operate at the remote site without any delay or feature degradation. Unlike a centralized architecture, which may require several skill sets to manage and recover, the ShoreTel UC system is a single-image system across all geographies, with complete feature transparency. Dial tone is never lost, so callers do not detect any faults.

Presence, Other Features Stay Live During Switchover
Furthermore, presence, which enables callers to see whether the people they are calling are available, IM discussion and other communications features continue to be supported through a switchover, and remain accessible through ShoreTel ShoreWare® Personal Call Manager. For organizations with a mission-critical communications system, the robust disaster recovery features of the ShoreTel UC system help keep everyone in touch, whether there’s been a terrorist attack, a snowstorm, or simply a spike in the number of staff who work remotely.

“With the ShoreTel UC system, employees can simply log in from home, and then take full advantage of inbound and outbound calling features and all data applications,” Winslow says. “As telecommuting increases in the face of steadily rising gas prices and an ever more distributed workforce, these features help organizations maintain a professional brand, even when half of the employees are working from home, in hotel rooms or out of other offices in the course of business travel.”

The ShoreTel UC system also supports remote backup sites at redundant data centers. In the event of a disaster that alerts the backup site to go live, key capabilities of the ShoreTel UC phone system remain intact during the switch from the primary server to the backup server. The switchover takes seconds or minutes, depending on the network configuration and where the primary and secondary ShoreTel sites are geographically located.

Interconnectedness’ Risks and Benefits
In today's interconnected world, virtually every aspect of a company's operation is vulnerable to disruption. In a competitive environment, even a few hours of downtime could prove catastrophic. Keeping all lines of communication open is key to maintaining continuous daily operations and staying in touch in an "always on" 24x7, global environment. The ShoreTel UC system offers proven strategies that help keep communications available and reduce the risks associated with downtime—lost revenue, degraded customer service, and lost productivity.

“Regardless of the features installed, organizations need a communications system that is rock-solid from an architectural point-of-view,” Winslow says. “ShoreTel provides a structurally sound foundation that helps ensure employees have continual access to its state-of-the-art feature-rich environment.”

For more information about ShoreTel’s approach to designing UC solutions that can recover quickly from both minor outages and major events, see Building Reliable IP Telephony Systems, a white paper prepared by Ed Basart, ShoreTel’s CTO and co-founder.