Lotus Sametime Unified Telephony permits optional provisioning of primary and secondary link capacities for each CAC (Call Admission Control) Policy. The ability permits the support of an access router that can switch over to a backup link (with a different bandwidth capacity) than the primary link, if the primary link fails.
Figure 1. Sample Configuration for Dynamic Handling of Link Failures
The primary or secondary capacity can be dynamically selected by the customer's network management system (NMS) via a SOAP/XML interface. If the NMS becomes aware of an access router's link failure, it uses the Link Failure Web Service to notify Lotus Sametime Unified Telephony to use the secondary capacity for the CAC policy of the associated access link. If the primary link access is restored, the Link Failure Web Service also provides a command to Lotus Sametime Unified Telephony to switch back to the primary capacity of the CAC policy.
When a backup link having a different bandwidth capacity than the primary link exists for a given CAC Group, additional parameters need to be defined in the corresponding CAC Group and CAC Policy configuration.
The Figure below provides a simple example of this configuration:
For this example, the CAC Group and CAC Policy shown in the figure below must be created for the branch office:
Figure 2. Sample CAC Group and CAC Policy for Dynamic Handling of Link Failures
Parent topic: CAC (Call Admission Control)