Design and Implementation of Multi‑Site Active‑Active Disaster Recovery for Call Centers

As business volume continuously grows, call centers are transitioning from a single large‑capacity hub to a multi‑site architecture; unified collaboration across locations becomes essential for resource integration, availability improvement, and efficiency gains. Existing large‑scale call centers typically adopt a multi‑site load‑sharing network, deploying both server and agent endpoints across regions to lower operational risk and enhance availability.

Although this deployment enables uninterrupted service, it cannot provide seamless disaster recovery; a failure at one site inevitably reduces overall handling capacity (agent sign‑in loss). Introducing system‑level active‑active capabilities further safeguards service continuity, ensuring cross‑regional disaster tolerance and minimizing the impact of single‑region outages.

The active‑active function is built on Ctrip's Contact Center and Unified Login platforms, offering both planned DR switches (by system, city region, or skill group) and unplanned switches covering PBX, CTI, and login failures.

Implementation relies on the Ctrip Call Center platform, continuously monitoring communication and registration status among the agent client, CTI/Unified Login, IP phone, and PBX. Based on these observations, the platform determines current availability and executes the following agent login logic:

Agent client initiates a login request.

If the local unified login is unavailable, the request is sent directly to the remote unified login.

If the local login is normal, a request is sent to the local unified login.

Upon receiving the request, the unified login checks whether planned switch is enabled; if so, it requests resources from the remote platform according to the configured rules; otherwise, it allocates resources locally and returns registration information to the agent client, which then proceeds with CTI registration and IP‑phone linkage.

If CTI registration or IP‑phone linkage fails during this process, a login request is re‑issued to the remote unified login.

After a successful login, the agent client continuously monitors the Client‑CTI‑PBX‑IP‑phone interaction to detect any faults. When a failure is detected, the client performs a secondary confirmation; upon confirming a broken link, it automatically initiates an active‑active failover by sending a re‑login request to the remote unified login platform, all without human intervention.

Key technical characteristics include support for automatic active‑active switching of online agents during faults, manual switching for planned maintenance, switchability by system, region, or skill group, and the ability to handle over 1,000 online agents in an active‑active scenario.

Looking forward, by integrating Ctrip's CTI platform and unified login, the active‑active capability can manage PBX, CTI, and login services in the cloud, achieving a "one‑stop" global service where agents are no longer bound to a specific region and can connect from a single point to serve worldwide.