Configuring Call Survivability for Call Centers

The device supports call survivability for call centers. When a communication failure (e.g., in the network) occurs with the remote voice application server responsible for handling the call center application (such as IVR), the device routes the incoming calls received from the customer (i.e., from the TDM gateway) to the call center agents.

In normal operation, the device registers the agents in its users registration database. Calls received from the TDM gateway are forwarded by the device to the application server, which processes the calls and sends them to specific call center agents, through the device. Upon a failure with the application server, the device routes the calls from the TDM Gateway to the agents. The device routes the call to the first available user it founds. If the call is not answered by the user, the device routes it to the next available user. The SBC can handle a sequence of up to five users, after which the session is timed out and the call is dropped.

To configure call survivability for a call center application:
1. In the IP Groups table (see Configuring IP Groups), add IP Groups for the following entities:
TDM Gateway (Server-type IP Group). This entity forwards the customer calls through the device to the Application server.
Application server (Server-type IP Group). This entity processes the call and sends the call through the device to the specific call center agent located on a different network (remote).
Call center agents (User-type IP Group). You can configure multiple IP Groups to represent different groups of call center agents, for example, agents and managers.
2. In the Classification table (see Configuring Classification Rules), add rules to classify incoming calls that are received from the entities listed in Step 1, to IP Groups.
3. In the SBC IP-to-IP Routing table (see Configuring SBC IP-to-IP Routing Rules), add the following IP-to-IP routing rules:
For normal operation:
Routing from TDM Gateway to Application server.
Routing from Application server to call center agents.
For call survivability mode: Routing from TDM Gateway to call center agents. This configuration is unique due to the following settings:
The 'Source IP Group' field is set to the IP Group of the TDM Gateway.
The 'Destination Type' field is set to Hunt Group, which is specifically used for call center survivability.
The 'Destination IP Group' field is set to the IP Group of the call center agents.

The figure below displays a routing rule example, assuming IP Group #1 represents the TDM Gateway and IP Group #3 represents the call center agents: