It’s common practice to set enterprise telephony networks in a “hub and spoke” topology where branch offices connect over the WAN to a centralized site where calls are routed internally and externally. This saves money by centralizing administration and limiting external access points.
But what happens if there is an interruption in WAN access? Branch offices will be unable to contact external parties. If internal call routing is handled through the same centralized facility, people in the same office won’t be able to call or send instant messages to one another.
Ribbon has two solutions to maintain intra-company communications in the event of a WAN failure. The Survivable Branch Appliance (SBA) ensures that basic unified communications services are available locally in the event that network connectivity to the remote site is lost. The Resilient Branch Appliance (RBA) provides a mobile broadband 3G/4G connection to keep signaling and data layers operational in the event of a WAN outage.