Redundancy Support In Ecs; Intra-Chassis Session Recovery Interoperability; Recovery From Task Failure; Recovery From Cpu Or Packet Processing Card Failure - Cisco ASR 5000 Series Administration Manual

▀ Redundancy Support in ECS

Redundancy Support in ECS
This section describes the redundancy support available in ECS to recover user sessions and charging records in the
event of software/hardware failure.
Caution:
Important:

Intra-chassis Session Recovery Interoperability

Intra-chassis session recovery is coupled with SessMgr recovery procedures.
Intra-chassis session recovery support is achieved by mirroring the SessMgr and AAAMgr processes. The SessMgrs are
paired one-to-one with the AAAMgrs. The SessMgr sends checkpointed session information to the AAAMgr. ECS
recovery is accomplished using this checkpointed information.
Important:
standby and three active. Per active CPU with active SessMgrs, there is one standby SessMgr, and on the standby CPU,
the same number of standby SessMgrs as the active SessMgrs in the active CPU.
There are two modes of session recovery, one from task failure and another on failure of CPU or packet processing card.

Recovery from Task Failure

When a SessMgr failure occurs, recovery is performed using the mirrored "standby-mode" SessMgr task running on the
active packet processing card. The "standby-mode" task is renamed, made active, and is then populated using
checkpointed session information from the AAAMgr task. A new "standby-mode" SessMgr is created.

Recovery from CPU or Packet Processing Card Failure

When a PSC, PSC2, or PPC hardware failure occurs, or when a planned packet processing card migration fails, the
standby packet processing card is made active and the "standby-mode" SessMgr and AAAMgr tasks on the newly
activated packet processing card perform session recovery.

Inter-chassis Session Recovery Interoperability

The system supports the simultaneous use of ECS and the Inter-chassis Session Recovery feature. (For more
information on the Inter-chassis Session Recovery feature, refer to the System Administration Guide.) When both
features are enabled, ECS session information is regularly checkpointed from the active chassis to the standby as part of
normal Service Redundancy Protocol processes.
In the event of a manual switchover, there is no loss of accounting information. All xDR data from the active chassis is
moved to a customer-configured ESS before switching over to the standby. This data can be retrieved at a later time.
▄ Cisco ASR 5x00 Enhanced Charging Services Administration Guide
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Persistent data flows are NOT recoverable during session recovery.
Redundancy is not available in the current version of the Cisco XT2 platform.
In order for session recovery to work there should be at least four packet processing cards, one
Enhanced Charging Service Overview