ASR 5500 supports
Assume Positive configurations, and this feature is tailored to provide the
service to users even when the Online Charging Server (OCS) is unreachable.
This Assume Positive configuration allows the users to configure the
interim-quota (either volume or time or both together along with the number of
retries) that can be used when the charging servers are unreachable or not
responding. This feature also lets the user to configure the action to be taken
when the interim-quota and retries are exhausted.
In the existing
implementation with Assume Positive feature, there are high chances of losing
the usage data reported through the CCR-T when the session is being terminated
while in Assume Positive mode. This problem is addressed by allowing the DCCA
module to write the CCR-T messages (with locally assigned quota details) in the
HDD of the chassis.
In cases where the
Assume-Positive interim-quota is allocated, and CCR-T is not reported/answered,
the CCR-T message is written to a local file, and saved in the HDD. This local
file and directory information can be fetched and parsed to account for the
lost bytes/usage. The retrieval of the file can be done with the PULL
requires a valid license to be installed prior to configuring this feature.
Contact your Cisco account representative for more information on the licensing
In releases prior to 20, failed CCR-T is written to HDD only if
the session is in Assume Positive state. In Release 20 and later, the existing
behavior is modified such that, even if the sessions are not in Assume Positive
state, the failed CCR-Ts are written to HDD for later processing. This
enhancement is applicable for all CCR-T failures like Tx/response timeouts,
result code errors, diabase errors, etc.
In case of Session Recovery, if a DCCA session which is in
pending-terminate state is recovered, then a fresh CCR-T will be initiated.
This CCR-T will be written to hard disk if it fails. In case of ICSR, the
sessions which are already in terminating state are not recovered.
Once the bearer/session gets terminated, the same in the standby
will be deleted and that session will not come up in case of ICSR.
This feature is
controlled through the CLI command "diameter hdd" introduced in the Credit Control
Group configuration mode. When the CLI configuration is enabled, the DCCA
application sends the failed CCR-T messages to the CDR module for storing in