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| FAULT TOLERANCE |
Figure C.1 shows the architecture for a fault tolerant EDACS billing system.
| RF |
|
| System |
|
Console | Primary | Backup |
Downlink | Downlink | |
Terminal |
|
|
BCU
BCU
Console
Terminal
| MIM |
| MIM |
|
|
| (Backup) |
| |
| (Primary) |
|
|
C
A
M
AREA
CIMC
A M
To StarGate
Figure C.1 - EDACS Billing Fault Tolerant Architecture
Redundant MIM processors are added to each RF System interface within the IMC. A duplicate CAM is added, which connects to the redundant BCU/CAL and tape drive.
REDUNDANT OPERATION
The primary and redundant MIM processors operate in a hot standby configuration, i.e., once primary unit failure is detected, the backup becomes the active processor with minimal disruption to calls in progress. The redundant CAM, BCU/CAL and tape drive are operated as