Inter-Chassis Session Recovery Interoperability - Cisco ASR 5000 series Product Overview

▀ Redundancy Support in ECS

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 and Configuration 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.
Upon completion of the switchover, the ECS sessions are maintained and the ―now-active‖ chassis recreates all of the
session state information including the generation of new xDRs.
In the event of an unplanned switchover, all accounting data that has not been written to the external storage is lost.
(Note that either the ESS can pull the xDR data from the chassis, or the chassis can push the xDR files to a configured
ESS at user-configured intervals. For more information, see
switchover, the ECS sessions are maintained and the ―now-active‖ chassis recreates all of the session state information
including the generation of new xDRs.
Regardless of the type of switchover that occurred, the names of the new xDR files will be different from those stored in
the /records directory of packet processing card RAM on the ―now-standby‖ chassis. Also, in addition to the file name,
the content of many of the fields within the xDR files created by the ―now-active‖ chassis will be different. ECS
manages this impact with recovery mechanism. For more information on the differences and how to correlate the two
files and other recovery information, see the
Inter-chassis Session Recovery Architecture
Inter-chassis redundancy in ECS uses Flow Detail Records (FDRs) and UDRs to manage the switchover between
Active-Standby system. xDRs are moved between redundant external storage server and Active-Standby systems.
Recovery from L-ESS Failure
External storage server is responsible for sending records (pulled/pushed from the chassis) to the billing system. A
cluster of two L-ESSs is implemented to fulfill the requirements for L-ESS redundancy.
Impact on xDR File Naming
The xDR file name is limited to 256 characters with following syntax:
basename_ChargSvcName_ timestamp_SeqNumResetIndicator_FileSeqNumber
where:
basename: A global configurable text string that is unique per system that uniquely identifies the global location
of the system running ECS.
▄ Cisco ASR 5000 Series Product Overview
External Storage System
Impact on xDR File Naming
Enhanced Charging Service Overview
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