7.8 PDN GW initiated Resource Allocation Deactivation
23.1393GPP3GPP system - fixed broadband access network interworkingRelease 17Stage 2TS
This procedure is applicable if the UE accesses a Fixed Broadband Access network with GTPv2 or PMIPv6 based S2b interface. And the PDN GW initiated the resource releasing procedure, for example, due to IP‑CAN session modification requests from the PCRF or due to handover from Fixed Broadband Access network to 3GPP. When it is performed due to a handover, the connections associated with the PDN address are released, but the PDN address is kept in the PDN GW.
Figure 7.8-1: PDN GW Initiated Bearer Deactivation
NOTE 1: In the roaming case, the Step 2 terminates at the V-PCRF.
If dynamic policy provisioning over S9a is not deployed, the optional steps 2 and 3 do not occur. Instead, the Fixed Broadband Access network may employ Fixed Broadband Access local policies.
Step 2 is only applicable when S2b PMIPv6 is used.
1. The description of the step is the same as it is in TS 23 402 [3], clause 7.9.1 or 7.9.2 with following exceptions:
– The step 4 in clause 7.9.1 or step 3b in clause 7.9.2 is not executed.
2. Triggered by the IPSec tunnel termination, the ePDG terminates the Gxb* session. This step is only applicable when S2b PMIPv6 is used and Gxb* was used to trigger initiation of the S9a session from PCRF. This step may occur at any time.
NOTE 2: Step 2 may occur before or after steps 3-5. Step 2 does not trigger step 3.
3. Triggered by step 1, the PCRF (for non-roaming case) and the V-PCRF (for the home routed and visited access roaming case) executes a Gateway Control and QoS Rules Provision procedure or, if this is the last PDN Connection for the UE over Fixed Broadband Access, a PCRF-Initiated Gateway Control Session Termination Procedure with the BPCF. In roaming scenario, for the case when GTP is used on S2b, the H-PCRF will initiate the procedure over S9 towards the V-PCRF and the V-PCRF in turns initiates the procedure over S9a towards the BPCF.
4. The resources may be released in the Fixed Broadband Access, according to an access specific release mechanism. The details of this step are out of the scope of this specification.