Maintenance and Failover in the BGF Overview
By providing redundancy for both the Routing Engine and the service PICs, the BGF high-availability (HA) architecture allows for a multilevel redundant solution. This solution ensures service and call continuity, which is necessity for VoIP services.
Figure 1 shows the BGF HA architecture.
Figure 1: BGF HA Architecture
Table 1 indicates how service PIC or MS-DPC failure and Routing Engine failure affect different types of services.
Table 1: How Service PIC and Router Engine Failures Affect Service and Call Continuity
| Service | Service PIC or MS-DPC Failure | Routing Engine Failure |
|---|---|---|
Stable H.248 contexts | Call continuity—All calls are lost. Service continuity—Provided when the backup PIC or DPC is available. | Call continuity—All existing calls are maintained through the failure Service continuity—New calls and session can be established when the backup Routing Engine takes control. |
H.248 contexts are modified | Call continuity—All existing call states are lost. Service continuity—Calls and sessions that are in a Setup state (gates and terminations not fully defined) are lost | Call continuity—All existing call states are lost. Service continuity—Calls and sessions that are in a Setup state are lost. |
Connection to the gateway controller | Call continuity—All calls are lost. Service continuity—Provided when the backup service PIC or DPC is available. | Call continuity—No calls are lost. Service continuity—Provided when the backup Routing Engine takes control. |
