Out-of-the-box, when a Gx Session fails, the PCRF initiates termination of an
associated Rx session by sending an Rx ASR to the AF.
You can answer y to the following
create_config.info question to keep the Rx session if the
associated Gx session fails:
Global:Session:Application:Notify:Keep application session on policy session failure(y/n)?
After enabling Rx session retention, if there is a Gx session failure, the Rx session
continues as shown in Figure 1 and
Figure 2.
In Figure 1, an IP Multimedia Subsystem
(IMS) call is in progress and there is a new media request causing policy rules to
update. A Gx RAR is returned with the updated rules, but the rules fail to install.
At this point, the Gx session is terminated, but the Rx session continues until the
IMS call is terminated.Figure 1. Rule Installation Failure
In Figure 2, an IP Multimedia Subsystem
(IMS) call is in progress and there is a new media request causing policy rules to
update. A Gx RAR is returned with the updated rules, but after several resend
attempts, there is no response. At this point, the Gx session is terminated, but the
Rx session continues until the IMS call is terminated.
Note: Gx
RAR retry attempts are set using the following
create_config.info notification retry questions:
Global:Session:Policy:Notify:How many attempts?
Global:Session:Policy:Notify:How long (in seconds) to wait after each attempt?
