Impact On Xdr File Content - Cisco ASR 5000 Series Administration Manual

▀ Redundancy Support in ECS
 FileSeqNumber—Unique file sequence number for the file with nine-digit integer having range from 000000000
to 999999999. It is unique on each system.
With inter-chassis session recovery, only the first two fields in the xDR file names remain consistent between the active
and standby chassis as these are parameters that are configured locally on the chassis. Per inter-chassis session recovery
implementation requirements, the two chassis systems must be configured identically for all parameters not associated
with physical connectivity to the distribution node.
The fields "timestamp", "SeqNumResetIndicator", and "FileSeqNumber" are all locally generated by the specific
system through CDR subsystem, regardless of whether they are in an Inter-chassis Session Recovery arrangement or
not.
 The "timestamp" value is unique to the system generating the actual xDRs and generated at the time the file is
opened on the system.
 The SeqNumResetIndicator is a unique counter to determine the number of resets applied to FileSeqNumber.
This counter is generated by CDR subsystem and increment the counter in event of resets in FileSeqNumber.
This is required as "timestamp" field is not sufficient to distinguish between a unique and a duplicate xDR.
As such, the "SeqNumResetIndicator" field is used to distinguish between xDR files which have the same
"FileSeqNumber" as a previously generated xDR as a result of:
 Normal operation, for example a rollover of the "FileSeqNumber" from maximum limit to 0.
 Due to a failure of one of the ECS processes running on a packet processing card card.
 Failure of the system (that is, Inter-chassis Session Recovery switchover).
In any scenario where the "FileSeqNumber" is reset to 0, the value of the "SeqNumResetIndicator" field is incremented
by 1.
 The value of the "FileSeqNumber" is directly linked to the ECS process that is generating the specific xDRs.
Any failure of this specific ECS process results in resetting of this field to 0.

Impact on xDR File Content

The following scenarios impact the xDR file content:
 On failure of an active chassis:
On system startup, xDR files are generated in accordance with the standard processes and formats. If the
system fails at any time it results in an inter-chassis session recovery switchover from active to standby and the
following occurs depending on the state of the call/flow records and xDR file at the time of failure:
 Call/flow records that were being generated and collected in system memory prior to being written out
 Closed xDRs that have been written out to records directory on packet processing card RAM but that
 Closed xDRs that have been retrieved and processed by the ESS have no impact.
 On the activation of a Standby chassis:
Upon detection of a failure of the original active chassis, the standby chassis transits to the active state and
begins serving the subscriber sessions that were being served by the now failed chassis. Any subsequent new
subscriber session will be processed by this active chassis and will generate xDRs per the standard processes
and procedures.
However, this transition impacts the xDRs for those subscribers that are in-progress at the time of the
transition. For in progress subscribers, a subset of the xDR fields and their contents are carried over to the
▄ Cisco ASR 5x00 Enhanced Charging Services Administration Guide
80
to /records directory on packet processing card RAM are not recoverable and therefore are lost.
have yet to be retrieved by the ESS are recoverable.
Enhanced Charging Service Overview