Cisco ASR 5000 Administration Manual page 120

▀ Features and Terminology
Figure 17.
Tx Timer Expiry Behavior
A timer is started each time a CCR is sent out from the system, and the response has to arrive within Tx time. The
timeout value is configurable in the Diameter Credit Control Configuration mode.
In case there is no response from the Diameter server for a particular CCR, within Tx time period, and if there is an
alternate server configured, the CCR is sent to the alternate server after Tw expiry as described in "Tw Timer expiry
behavior" section.
It also depends on the Credit-Control-Session-Failover AVP value for the earlier requests. If this AVP is present and is
coded to FAILOVER_SUPPORTED then the credit-control message stream is moved to the secondary server, in case it
is configured. If the AVP value is FAILOVER_NOT SUPPORTED, then the call is dropped in case of failures, even if a
secondary server is configured.
Redirection
In the Final-Unit-Indication AVP, if the Final-Action is REDIRECT or Redirect-Server AVP is present at command
level, redirection is performed.
The redirection takes place at the end of consumption of quota of the specified category. The GY sends a CCR-Update
without any RSU or Rating-Group AVP so that the server does not give any more quotas.
If the Final-Action AVP is RESTRICT_ACCESS, then according to the settings in Restriction-Filter-Rule AVP or
Filter-Id AVP. GY sends CCR-Update to the server with used quota.
Triggers
▄ Cisco ASR 5000 IP Services Gateway Administration Guide
120
Gy Call Flow for Simple Call Request for HA
Gy Interface Support
OL-27210-02