PDN Attach with only Offline Rules

The following call flow and procedure describes PDN attach when dynamic rule with offline is enabled through Gx and Gz interfaces.

Call Flow

Call Flow
Call Flow Description for PDN Attach
Step Description
1

SMF sends Gx CCR-I towards PCRF.

2

PCRF sends Gx CCA-I towards SMF with default bearer having Dynamic rule with OFFLINE_ENABLED set to True.

3

The N4 Establishment Request is sent towards UPF based on the following conditions:

  • CREATE_URR for default bearer level URR, if:

    • PFCP_IE_URR_ID is set to 0x80000002 for default bearer level URR

    • PFCP_IE_VOLUME_THRESHOLD and PFCP_IE_TIME_THRESHOLD has egcdr threshold values configured in rulebase profile.

    • PFCP_IE_MEASUREMENT_METHOD has both volume and duration bit set.

  • CREATE_URR for offline SDF level URR, if:

    • PFCP_IE_URR_ID has unique offline UrrId

    • PFCP_IE_VOLUME_THRESHOLD and PFCP_IE_TIME_THRESHOLD has egcdr threshold values configured in the GTPP profile.

    • PFCP_IE_MEASUREMENT_METHOD has both volume and duration bit set.

    • All SDF level offline URRs are linked to bearer level URR. That is, PFCP_IE_LINKED_URR_ID has linked URRId set to the BearerLevel URR.

  • PDR created for dynamic offline rule is mapped to both bearer and SDF level URR.

4

UPF sends N4Establishment response.