6.8 Network-initiated release of NBIFOM PDN connection

23.1613GPPNetwork-Based IP Flow Mobility (NBIFOM)Release 17Stage 2TS

6.8.1 General

The Network-initiated release of NBIFOM PDN connection procedure may be triggered by SIPTO, as defined in TS 23.401 [4]. In this case, the PDN GW initiates Bearer Deactivation procedure upon receiving a Release Over Any Access indication from the MME.

The Network-initiated release of NBIFOM PDN connection procedure may also be triggered due to P-CSCF Restoration, as defined in TS 23.380 [8]. In this case,

– The PDN GW initiates Bearer Deactivation procedure as described in clause 6.8.2 upon receiving a P-CSCF Restoration indication from the PCRF, the 3GPP AAA server, or the MME/SGSN, or

– The PDN GW initiates Bearer Deactivation procedure in WLAN upon receiving the Release Over Any Access indication from the MME/SGSN as described in clause 6.8.2.

– The MME sends the Release Over Any Access indication during the MME requested PDN disconnection procedure or MME-initiated Detach procedure upon receiving a P-CSCF Restoration indication from the HSS. Or,

– The SGSN sends the Release Over Any Access indication during the SGSN Initiated PDN connection Deactivation Procedure using S4 upon receiving a P-CSCF Restoration indication from the HSS.

6.8.2 PDN GW initiated procedures

6.8.2.1 PDN GW initiated bearer deactivation procedure

The PDN GW initiated bearer deactivation procedure defined in TS 23.401 [4] clause 5.4.4.1 shall be used with the following exceptions:

– Step 2:

If the PDN GW has received a P-CSCF restoration indication from the PCRF, the 3GPP AAA server, or the MME/SGSN, it shall select one access supporting the basic mechanism, based e.g. on whether the access supports the basic P-CSCF restoration mechanism defined in TS 23.380 [8]. If the PDN GW has selected the 3GPP access, it shall include the Reactivation Requested indication in the Delete Bearer Request to the MME. If the PDN GW has selected the WLAN access, it shall include the cause "local release" in the Delete Bearer Request to the MME.

– Steps 4 to 7 are not performed if the Cause in the Delete Bearer Request message is "local release".

6.8.2.2 PDN GW initiated Resource Allocation Deactivation with GTP on S2b procedure

For untrusted WLAN, the PDN GW initiated Resource Allocation Deactivation with GTP on S2b procedure defined in TS 23.402 [2] clause 7.9.2 shall be used with the following modifications:

– Step 2 applies with the following addition:

– If the PDN GW has received a P-CSCF restoration indication from the PCRF, the 3GPP AAA server, or the MME/SGSN, it shall select one access supporting the basic mechanism as defined in TS 23.380 [8]. If the PDN GW has selected the untrusted WLAN access, it shall include the Reactivation Requested indication in the Delete Bearer Request to the ePDG. If the PDN GW has selected the 3GPP access, it shall include the cause "local release" in the Delete Bearer Request to the ePDG.

– If this procedure is triggered by a Release Over Any Access indication from the MME, the PDN GW shall include the cause "local release" in the Delete Bearer Request to the ePDG.

– Step 3 is modified as follows: The IKEv2 tunnel release is triggered from the ePDG to the UE if all bearers belonging to the PDN connection are released and if the Cause in the Delete Bearer Request message is different from "local release". If the Delete Bearer Request message contains the Reactivation Requested indication, the ePDG includes the cause "Reactivation Requested" in the IKEv2 message to the UE.

6.8.2.3 PDN GW initiated Resource Allocation Deactivation in WLAN on GTP S2a procedure

For trusted WLAN, the PDN GW initiated Resource Allocation Deactivation in WLAN on GTP S2a procedure defined in TS 23.402 [2] clause 16.4.1 shall be used with the following modifications:

– Step 2 applies with the following addition:

– If the PDN GW has received a P-CSCF restoration indication from the PCRF, the 3GPP AAA server, or the MME/SGSN, it shall select one access supporting the basic mechanism as defined in TS 23.380 [8]. If the IMS PDN connection is established on both accesses with the single connection mode over the trusted WLAN, the PGW shall select the 3GPP access. Otherwise,

– If the PDN GW has selected the trusted WLAN access, it shall include the Reactivation Requested indication in the Delete Bearer Request to the TWAN;

– If the PDN GW has selected the 3GPP access, it shall include the cause "local release" in the Delete Bearer Request to the TWAN.

– If this procedure is triggered by a Release Over Any Access indication from the MME, the PDN GW shall include the cause "local release" in the Delete Bearer Request to the TWAN.

– Step 3 is modified as follows:

In multi-connection mode, if all bearers belonging to a PDN connection are released and if the Cause in the Delete Bearer Request message is different from "local release", then the UE is informed of the PDN connection release by means of a WLCP PDN Disconnection Request (PDN Connection ID). If the Delete Bearer Request message contains the Reactivation Requested indication, the TWAN includes the cause "Reactivation Requested" to the WLCP PDN Disconnection Request message to the UE.

6.8.2.4 PDN GW initiated Bearer Deactivation Procedure using S4

The PDN GW initiated bearer deactivation procedure using S4 defined in TS 23.060 [5] clause 9.2.4.3A shall be used with the following additions:

– Step A:

If the PDN GW receives a P-CSCF Restoration indication from the PCRF, the 3GPP AAA server, or the MME/SGSN, it shall select one access supporting the basic mechanism as defined in TS 23.380 [8]. If the PDN GW has selected the 3GPP access, it shall include the Reactivation Requested indication in the Delete Bearer Request to the SGSN. If the PDN GW has selected the WLAN access, it shall include the cause "local release" in the Delete Bearer Request to the SGSN.

– In addition, if the Cause in the Delete Bearer Request message is "local release", the message Deactivate PDP Context Request in step 2 of figure 77 in clause 9.2.4.3 is not sent to the UE.

Annex A (informative):
Change history

Change history

Date

Meeting

TDoc

CR

Rev

Cat

Subject/Comment

New version

2015-09-08

SP#69

SP-150508

MCC Editorial Update for presentation to TSG SA for Information and Approval

1.0.0

2015-09-08

SP#69

MCC Editorial Update to version 13.0.0 after TSG SA approval

13.0.0

2015-12

SP#70

SP-150607

0001

1

F

Access becomes usable/unusable in UE-initiated NBIFOM mode

13.1.0

2015-12

SP#70

SP-150607

0002

2

F

Clarification of addition of WLAN access in S2b

13.1.0

2015-12

SP#70

SP-150607

0003

F

Corrections to NBIFOM charging related descriptions

13.1.0

2015-12

SP#70

SP-150607

0004

2

F

Add missing RAN Rule indication procedures for UTRAN in Network-initiated NBIFOM mode

13.1.0

2015-12

SP#70

SP-150607

0006

3

F

Procedure updates for default access in UE-initiated NBIFOM mode

13.1.0

2015-12

SP#70

SP-150607

0007

3

F

Update of functional entities

13.1.0

2015-12

SP#70

SP-150614

0008

1

F

Clarification of the resource modification during Routing Rule exchange for SCM

13.1.0

2015-12

SP#70

SP-150607

0009

2

F

Assigning destination access for IP flow mapping

13.1.0

2015-12

SP#70

SP-150607

0011

3

F

Clarification for the information of IP Flow mapping

13.1.0

2016-03

SP#71

SP-160172

0012

F

Charging identities with multiple default bearers

13.2.0

2016-03

SP#71

SP-160172

0013

F

Correction to unusability indication

13.2.0

2016-03

SP#71

SP-160172

0015

1

F

Correction of NBIFOM procedure in SCM and RAN Rules handling parameter

13.2.0

2016-03

SP#71

SP-160172

0016

2

F

Correction to UE-initiated IP flow mapping/access usability change/RAN rule indication procedures in S2a MCM and S2b

13.2.0

2016-03

SP#71

SP-160172

0017

3

F

The procedure of removal of one access from the Multi-access PDN connection

13.2.0

2016-06

SP#72

SP-160294

0018

1

F

Correction of the decision of NBIFOM mode

13.3.0

2016-06

SP#72

SP-160294

0019

1

F

Correction of UE-initiated IP flow mapping procedure in GERAN/UTRAN

13.3.0

2016-06

SP#72

SP-160294

0020

2

F

Correction to the event triggers of NBIFOM

13.3.0

2016-06

SP#72

SP-160294

0021

1

F

Clarification of removal of one access from the PDN connection

13.3.0

2016-09

SP#73

SP-160641

0022

2

F

Clarifications and Corrections for NBIFOM

13.4.0

2016-09

SP#73

SP-160644

0023

5

C

Network-initiated release of NB-IFOM PDN connections

13.4.0

2016-12

SP#74

SP-160813

0024

2

F

NBIFOM with RAN Controlled WLAN Interworking

13.5.0

2017-03

F

Update to Rel-14 version (MCC)

14.0.0

2018-06

SP-80

Update to Rel-15 version (MCC)

15.0.0

2020-07

SP-88E

Update to Rel-16 version (MCC)

16.0.0

2022-03

SP-95E

Update to Rel-17 version (MCC)

17.0.0