31 Restoration of PDN connections after a PGW-C/SMF change

23.0073GPPRelease 18Restoration proceduresTS

31.1 General

The procedure specified in this clause enables to restore in the EPC the PDN connections affected by an PGW-C/SMF failure with or without restart or scale-in operation, and thus to maintain the UE connectivity to the PDN and corresponding services with minimum service interruption and minimal signalling in the network (e.g. no signalling wih the UE).

The procedure specified in this clause is optional to support for the MME, ePDG supporting S2b over GTPv2, SGW and PGW-C/SMF.

This procedure applies for combo PGW-C/SMF that are deployed in an PGW-C/SMF set (i.e. a set of PGW-C/SMF instances that are functionally equivalent and inter-changeable and that share the same contexts, see clause 5.21.3 of 3GPP TS 23.501 [45]).

In scenarios where a PGW-C/SMF becomes no longer available (e.g. PGW-C/SMF failure without restart, scale-in operation causing a PGW-C/SMF to be de-instantiated from the PGW-C/SMF set) or that require to change the PGW-C/SMF of a PDN connection, other PGW-C/SMFs from the same PGW-C/SMF set may take over the control of the PDN connections that were served by the PGW-C/SMF that is no longer available. When a PGW-C/SMF fails with restart, the restarted PGW-C/SMF should continue supporting the same PDN connections, if possible. When a PGW-C/SMF of a PGW-C/SMF set fails with or without restart, the Recovery (Restart Counter) shall not be incremented over S5/S8 (assuming the PDN connection context is still available in the PGW-C/SMF set).

The restoration of a PDN connection may be triggered by the MME (e.g. when the SGW detects and reports to the MME that the PGW-C has failed) or by the ePDG supporting S2b over GTPv2, or by the PGW-C/SMF (e.g. scale-in operation or PGW-C/SMF reselection by another network function such as PCF).

The procedure supports the restoration of Home Routed PDN connections, if the VPLMN and HPLMN support this procedure. If the VPLMN or HPLMN does not support this procedure, the existing behaviour applies, e.g. the MME and SGW clears all PDN connections of the PGW-C/SMF when detecting the failure or restart of the PGW-C/SMF and the MME may request UEs to release and reactivate some PDN connections (e.g. IMS PDN connections).

Clause 31.6 defines procedures to enable to restore a set of PDN connections affected by a PGW-C/SMF failure with or without restart, or scale-in operation, associated with specific FQ-CSIDs, Group IDs or PGW-C/SMF IP addresses.

31.2 PDN connection establishment or mobility to EPC

The PDN connection shall be established as defined in 3GPP TS 23.401 [15] with the following additions.

Figure 31.2-1: PDN connection establishment

1. During the PDN connection establishment or when a PDU session is moved from 5GS to EPS without the N26 interface, the MME may signal in the Create Session Request that it supports this procedure by including a PGW Set Support Indication. If the SGW also supports this feature, it shall relay this indication towards the PGW.

2. If the Create Session Request indicates support of this procedure, the PGW-C/SMF may return a PGW Change Info IE in the Create Session Response, that the SGW shall relay transparently towards the MME. The PGW Change Info IE shall contain the PGW Set FQDN or Alternative PGW-C/SMF FQDN or IP Addresses of PGW/SMFs in the set; receipt of this information indicates to the MME that this procedure is supported by the SGW and PGW-C/SMF for the PDN connection and that alternative PGW-C/SMF instances may be found using the PGW Set FQDN or the Alternative PGW FQDN or IP addresses, if the PGW-C/SMF becomes no longer reachable.

Likewise, a PDU session shall be moved from 5GS to EPS with the N26 interface as defined in clause 4.11 of 3GPP TS 23.502 [46] with the following additions:

– the MME may signal that it supports this procedure by including a PGW Set Support Indication in:

– the Create Session Request during 5GS to EPS Idle mode mobility using N26 interface (see clause 4.11.1.3.2 of 3GPP TS 23.502 [46]); and

– in the Modify Bearer Request during an 5GS to EPS handover using N26 interface (see clause 4.11.1.2.1 of 3GPP TS 23.502 [46]);

– If the SGW also supports this feature, it shall relay this indication in the Modify Bearer Request towards the PGW;

– If the Modify Bearer Request received by the PGW-C/SMF indicates support of this procedure, the PGW-C/SMF may return a PGW Change Info IE (with the same content as described above) in the Modify Bearer Response, that the SGW shall relay transparently towards the MME. This provides the same indication as described above to the MME.

31.2A PDN connection establishment or mobility to EPC/ePDG

The PDN connection shall be established as defined in clause 7.2.4 of 3GPP TS 23.402 [18] with the following additions.

Figure 31.2A-1: PDN connection establishment

1. During the PDN connection establishment or when a PDU session is moved from 5GS to EPC/ePDG, the ePDG may signal in the Create Session Request that it supports this procedure by including a PGW Set Support Indication.

2. If the Create Session Request indicates support of this procedure, the PGW-C/SMF may return a PGW Change Info IE in the Create Session Response. The PGW Change Info IE shall contain the PGW Set FQDN or Alternative PGW-C/SMF FQDN or IP Addresses of PGW/SMFs in the set; receipt of this information indicates to the ePDG that this procedure is supported by PGW-C/SMF for the PDN connection and that alternative PGW-C/SMF instances may be found using the PGW Set FQDN or the Alternative PGW FQDN or IP addresses, if the PGW-C/SMF becomes no longer reachable.

Likewise, a PDU session shall be moved from 5GS to EPC/ePDG as defined in clause 4.11.4 of 3GPP TS 23.502 [46] with the following additions:

– the ePDG may signal that it supports this procedure by including a PGW Set Support Indication in the Create Session Request during handover from 5GS to EPC/ePDG (see clause 4.11.4.2 of 3GPP TS 23.502 [46]); and

– If the Create Session Request received by the PGW-C/SMF indicates support of this procedure, the PGW-C/SMF may return a PGW Change Info IE (with the same content as described above) in the Create Session Response to provides the same indication as described above to the ePDG.

31.3 MME triggered PDN connection restoration

The MME may trigger a PDN connection restoration to move the PDN connection to a different PGW-C/SMF, e.g. when receiving a PGW Restart Notification from the SGW with the cause "PGW not responding", as defined in this clause.

Figure 31.3-1: MME triggered PDN connection restoration

1. The PGW-C/SMF fails without restart from the PGW-C/SMF set.

2. When detecting that the PGW-C/SMF has failed, the SGW-C shall send a PGW Restart Notification to the MME as specified in clause 16.1A.2.

When detecting that a PGW-C/SMF has failed, the SGW-C and MME shall maintain the contexts of the PDN connections served by that PGW-C/SMF for which this procedure is supported.

3. The MME should select an alternative PGW-C/SMF using the PGW Change Info received earlier from the PGW-C/SMF.

4. The MME shall send a Create Session Request including a PGW Change Indication towards the newly selected PGW-C/SMF, via the same or a different SGW. The MME may defer doing so until it needs to send signalling to the SGW or PGW-C. The MME should reuse the same SGW if possible, since the PDN connection restoration remains then transparent to the eNodeB. The PGW Change Indication tells the SGW and PGW-C/SMF that this is a request to move an existing PDN connection to the new PGW-C/SMF.

5. The new PGW-C/SMF shall identify the PDN connection context using the UE’s identity (i.e. IMSI or IMEI) and the Linked EPS Bearer Identity received in the Create Session Request. If it can take over the PDN connection, it shall return a Create Session Response towards the SGW and MME (including, among others, the new S5/S8 PGW F-TEID for control plane, its PGW node name and S5/S8 PGW F-TEIDs). The PGW-C/SMF shall not change the UE’s IP address.

The SGW and MME shall update their PDN connection context with the information received from the PGW-C/SMF. Any subsequent control plane procedure between the MME, SGW and PGW shall take place as defined in existing procedures.

If the MME reselected a different SGW, the MME shall update the eNB with the new SGW’s S1-U F-TEID using the MME triggered Serving GW relocation procedure (see clause 5.10.4 of 3GPP TS 23.401 [15]).

6. The MME shall update the PGW identity in the HSS. Upon detecting that the association between APN and PGW-C/SMF FQDN is changed, if an active subscription from the UDM exists for the UE to be notified on the change of the data, the HSS shall notify the UDM as specified in Figure 5.3.4-5 of clause 5.3.4 of 3GPP TS 23.632 [47].

NOTE 1: An active subscription from the UDM can exist e.g. to notify the AMF registered for the UE for non-3GPP access.

NOTE 2: The PDN connection restoration procedure specified in this clause does not require any specific handling from the HSS and UDM.

31.3A ePDG triggered PDN connection restoration

The ePDG supporting S2b over GTPv2 may trigger a PDN connection restoration to move the PDN connection to a different PGW-C/SMF, e.g. when detecting that the PGW/SMF is not reachable, as defined in this clause.

Figure 31.3A-1: ePDG triggered PDN connection restoration

1. The PGW-C/SMF fails without restart from the PGW-C/SMF set.

2. The ePDG detects that the PGW-C/SMF has failed as specified in clause 20.1.

When detecting that a PGW-C/SMF has failed, the ePDG shall maintain the contexts of the PDN connections served by that PGW-C/SMF for which this procedure is supported.

3. The ePDG should select an alternative PGW-C/SMF using the PGW Change Info received earlier from the PGW-C/SMF.

4. The ePDG shall send a Create Session Request including a PGW Change Indication towards the newly selected PGW-C/SMF. The ePDG may defer doing so until it needs to send signalling to the PGW-C. The PGW Change Indication tells the PGW-C/SMF that this is a request to move an existing PDN connection to the new PGW-C/SMF.

5. The new PGW-C/SMF shall identify the PDN connection context using the UE’s identity (i.e. IMSI or IMEI) and the Linked EPS Bearer Identity received in the Create Session Request. If it can take over the PDN connection, it shall return a Create Session Response towards the ePDG (including, among others, the new S5/S8 PGW F-TEID for control plane, its PGW node name and S2b PGW F-TEIDs). The PGW-C/SMF shall not change the UE’s IP address.

The ePDG shall update their PDN connection context with the information received from the PGW-C/SMF. Any subsequent control plane procedure between the ePDG and PGW shall take place as defined in existing procedures.

6. The new PGW-C/SMF shall update the PGW identity in the 3GPP AAA Server, and the 3GPP AAA server will further populate the PGW identity to the HSS as specified in clause 12.1.4 of 3GPP TS 23.402 [18]. The new PGW-C/SMF shall update the PGW identity to the UDM as specified in clause 4.11.4.3.6 of 3GPP TS 23.502 [46] if S6b is not deployed between SMF+PGW-C and 3GPP AAA Server.

31.4 PGW triggered PDN connection restoration

The PGW-C/SMF currently supporting a PDN connection, or a new PGW-C/SMF from the same PGW-C/SMF set, may trigger a PDN connection restoration to move the PDN connection to a different PGW-C/SMF as defined in this clause.

This may happen e.g. when a PGW-C/SMF is de-instantiated (scale-in operation), or when a new PGW-C/SMF from the same PGW-C/SMF set is reselected for the PDN connection upon a request from the PCF or the PGW-U/UPF and, more generally, when the PGW-C/SMF supporting a PDN connection is no longer available and a new PGW-C/SMF of the same PGW-C/SMF set needs to send signalling to the SGW or MME, before the MME has triggered a PDN connection restoration.

Figure 31.4-1: PGW triggered PDN connection restoration

1. The PGW-C/SMF currently supporting the PDN connection or another PGW-C/SMF from the same PGW-C/SMF set determines that the PDN connection needs to be moved to a different PGW-C/SMF, e.g. during a PGW-C/SMF set scale-in operation, or e.g. due to PCF or PGW-U/UPF reselecting an alternative PGW-C/SMF from the same PGW-C/SMF set due to the PGW-C/SMF serving the PDN connection being unavailable and this triggers bearer signalling towards the MME.

2 or 3. The PGW-C/SMF currently supporting the PDN connection or the new PGW-C/SMF taking over the PDN connection may send an Update Bearer Request for the default bearer towards the SGW immediately or send Create Bearer Request (or a Update Bearer Request or a Delete Bearer Request) when the PGW-C/SMF needs to send this signalling towards the SGW and MME, including the PGW Change Info IE. The SGW shall relay transparently the PGW Change Info IE towards the MME. The PGW Change Info IE shall contain the new S5/S8 PGW IP address for control plane.

4. Same as step 4 of Figure 31.3-1, with the MME including in the Create Session Request the new S5/S8 PGW-C/SMF IP address received in the PGW Change Info.

5. Same as step 5 of Figure 31.3-1.

6. Same as step 6 of Figure 31.3-1.

31.4A Combined SGW-C/PGW-C/SMF triggered PDN connection restoration

A combined SGW-C/PGW-C/SMF currently supporting a PDN connection, or a new SGW-C/PGW-C/SMF from the same SGW-C/PGW-C/SMF set, may trigger a PDN connection restoration to move the PDN connection to a different SGW-C/PGW-C/SMF as defined in clause 31.4 with the following addition:

– In step 2, the (new) SGW-C/PGW-C/SMF may include a New S11 SGW-C IP Address IE in the PGW Change Info IE to request the MME to send Create Session Request message towards the new S11 SGW-C IP address, so to enable to reuse the existing PFCP session and avoid extra signalling towards RAN to update uplink TEID at the user plane function.

– In step 4, the MME should send the Create Session Request message towards the SGW as indicated in the New S11 SGW-C IP Address IE in the PGW Change Info IE.

NOTE: The MME can still select a new SGW other than as indicated by the New SGW-C IP Address IE when the MME determines that that SGW is more suitable for the UE e.g. based on the local policies and UE location.

31.4B PGW triggered PDN connection restoration towards ePDG

The PGW-C/SMF currently supporting a PDN connection, or a new PGW-C/SMF from the same PGW-C/SMF set, may trigger a PDN connection restoration to move the PDN connection to a different PGW-C/SMF as defined in this clause.

This may happen e.g. when a PGW-C/SMF is de-instantiated (scale-in operation), or when a new PGW-C/SMF from the same PGW-C/SMF set is reselected for the PDN connection upon a request from the PCF or the PGW-U/UPF and, more generally, when the PGW-C/SMF supporting a PDN connection is no longer available and a new PGW-C/SMF of the same PGW-C/SMF set needs to send signalling to the ePDG, before the ePDG has triggered a PDN connection restoration.

Figure 31.4B-1: PGW triggered PDN connection restoration towards ePDG

1. The PGW-C/SMF currently supporting the PDN connection or another PGW-C/SMF from the same PGW-C/SMF set determines that the PDN connection needs to be moved to a different PGW-C/SMF, e.g. during a PGW-C/SMF set scale-in operation, or e.g. due to PCF or PGW-U/UPF reselecting an alternative PGW-C/SMF from the same PGW-C/SMF set due to the PGW-C/SMF serving the PDN connection being unavailable and this triggers bearer signalling towards the ePDG.

2 or 3. The PGW-C/SMF currently supporting the PDN connection or the new PGW-C/SMF taking over the PDN connection may send an Update Bearer Request for the default bearer towards the ePDG immediately or send Create Bearer Request (or a Update Bearer Request or a Delete Bearer Request) when the PGW-C/SMF needs to send this signalling towards the ePDG, including the PGW Change Info IE. The PGW Change Info IE shall contain the new S2b PGW IP address for control plane.

4. Same as step 4 of Figure 31.3A-1, with the ePDG including in the Create Session Request the new S5/S8 PGW-C/SMF IP address received in the PGW Change Info.

5. Same as step 5 of Figure 31.3A-1.

6. Same as step 6 of Figure 31.3A-1.

31.5 Inter-MME or AMF-MME mobility

During inter-MME mobility, the source MME shall transfer the PGW Change Info to the target MME, if available.

During a 5GS to EPS mobility procedure (See also clauses 4.11.1.2.1 and 4.11.1.3.2 of 3GPP TS 23.502 [46]), the PGW Change Info shall be populated as part of the MME/SGSN/AMF UE EPS PDN Connections IE from the source AMF to the target MME, if available. For a Home-routed PDU session or a PDU session with an I-SMF, the (H-)SMF may pass the PGW Change Info in the EpsPdnCnxInfo to the V/I-SMF prior to the 5GS to EPS mobility procedure, to enable the V/I-SMF to include the PGW Change Info in the EpsPdnCnxContainer as part of the SmContextRetrievedData. For a non-roaming PDU session without I-SMF, the PGW-C/SMF may include the PGW Change Info directly in the EpsPdnCnxContainer.

NOTE: Passing the PGW Change Info from the SMF/AMF to the MME during an 5GS to EPS mobility enables the target MME to reselect an alternative PGW-C/SMF if the anchor PGW-C/SMF handling the PDU session fails before or during the handover. Requirements specified in clause 31.2 allow the target MME to reselect an alternative PGW-C/SMF if the anchor PGW-C/SMF handling the PDU session fails after the handover execution.

31.6 Restoration of PDN connections and PFCP sessions associated with a specific FQ-CSID, Group ID or PGW-C/SMF IP Address

31.6.1 General

To reduce signalling latency and achieve a better load balancing among PGW-C/SMFs in a Set, an PGW-C/SMF, MME, ePDG supporting S2b over GTPv2 and UPF may support the procedures specified in this clause. These procedures enable an SMF/PGW-C to request MME/ePDG supporting S2b over GTPv2/UPF to move PDN connections and PFCP sessions associated with certain FQ-CSIDs (when partial failure handling is supported), Group IDs or PGW-C/SMF IP Addresses, to (another) PGW-C/SMF(s) in the set, without causing massing signalling.

NOTE: The FQ-CSID can only be used in the procedure specified in this clause when the partial failure feature (using FQ-CSID) is deployed and used (not to force the NF to use a Group ID). For a network where the partial failure feature is not deployed, a Group ID or a PGW-C/SMF IP address needs to be used.

The requirements specified in this clause shall apply in addition to the previous requirements specified in clause 31.

31.6.2 Allocation of Group Id or FQ-CSID to a PDN connection or a PFCP session

To optimize the resource utilization for PDN connection(s) and/or PFCP session(s), e.g. to meet different traffic requirements for different APNs/DNNs and/or DCNs/Network Slices, and also to facilitate moving a (sub)set of PDN connections/PFCP sessions among a PGW-C/SMF set, e.g. for a partial or complete PGW-C/SMF failure or a scale-in operation, a PGW-C/SMF in a PGW-C/SMF Set may:

– allocate a globally unique Group Id in the PGW Change Info IE in the Create Session Response message for a PDN connection during a PDN connection creation procedure and mobility procedure moved from 5GC without N26, or in the Modify Bearer Response for a PDN connection moved from 5GC with N26, and update the Group Id associated to the PDN connection, if necessary, in subsequent Create/Update/Delete Bearer Request messages (see also 3GPP TS 29.274 [13]);

– allocate a globally unique Group Id in the PFCP Session Establishment Request message for a PFCP session during a PFCP session establishment procedure and update the Group Id, if necessary, in subsequent PFCP Session Modification Request messages (see also clause 5.22.X of 3GPP TS 29.244 [43]).

Alternatively, if partial failure handling is supported and deployed, the PGW-C/SMF may assign an FQ-CSID to a PDN connection and/or a PFCP session as specified in clause 23.

Subsequently, e.g. when a partial or a complete failure takes place affecting all PDN connections and PFCP sessions which are sharing either the same FQ-CSID or the same Group ID (see clause 31.6.1), a PGW-C/SMF in a PGW-C/SMF Set may trigger the restoration procedure for those affected PDN connections/PFCP sessions as specified in clauses 31.6.3 and 31.6.4.

31.6.3 Restoration of PDN connections associated with an FQ-CSID, Group ID or PGW-C/SMF IP Address

When there is a need to change the PGW-C/SMF controlling certain PDN connections, e.g. when a partial or complete PGW-C/SMF failure takes place, in order to trigger the MME(s) to re-establish the PDN connections that need to be taken over by a different PGW-C/SMF (e.g. PDN connections affected by the partial or complete failure), a PGW-C/SMF (either the one which experienced the partial failure or is shutting down, or another one in the same set) may trigger the PGW triggered PDN connection restoration procedure specified in clause 31.4 towards the MME or in clause 31.4a towards the ePDG, with the following additional requirements:

– in steps 2a or 2b, the PGW Change Info IE shall additionally include one or more PGW-C/SMF FQ-CSID(s) or one or more Group ID(s) or one or more PGW-C Control Plane IP Address(es), to request the MME/ePDG to re-establish all the PDN connections associated with the PGW-C/SMF FQ-CSID(s) or Group ID(s), or having their PGW S5/S8/ S2a/S2b F-TEID containing one of the PGW-C Control Plane IP Address(es), towards the new S5/S8/S2b PGW IP address for control plane. The PGW-C/SMF may instruct the MME/ePDG to move sessions associated with different PGW-C/SMF FQ-CSIDs, Group Ids or PGW-C/SMF Control Plane IP addresses to different PGW-C/SMF addresses.

31.6.3A Restoration of PDN connections associated with an FQ-CSID, Group ID or PGW-C/SMF IP Address for a combined SGW/PGW/SMF Set

When there is a need to change the combined SGW/PGW-C/SMF controlling certain PDN connections, e.g. when a partial or complete SGW/PGW-C/SMF failure takes place, in order to trigger the MME(s) to re-establish the PDN connections that need to be taken over by a different combined SGW/PGW-C/SMF (e.g. PDN connections affected by the partial or complete failure), a combined SGW/PGW-C/SMF (either the one which experienced the partial failure or is shutting down, or another one in the same set) may trigger the Combined SGW-C/PGW-C/SMF triggered PDN connection restoration procedure specified in clause 31.4a, with the following additional requirements:

– in steps 2a or 2b, the PGW Change Info IE shall additionally include one or more PGW-C/SMF FQ-CSID(s) or one or more Group ID(s) or one or more PGW-C Control Plane IP Address(es), to request the MME to re-establish all the PDN connections associated with the PGW-C/SMF FQ-CSID(s) or Group ID(s), or having their PGW S5/S8/ S2a/S2b F-TEID containing one of the PGW-C Control Plane IP Address(es), towards the new S5/S8 PGW IP address and the new S11 SGW-C IP Address IE for control plane. The combined SGW/PGW-C/SMF may instruct the MME to move sessions associated with different PGW-C/SMF FQ-CSIDs, Group Ids or PGW-C/SMF Control Plane IP addresses to different PGW-C/SMF addresses.

31.6.4 Restoration of PFCP sessions associated with an FQ-CSID, Group ID or PGW-C/SMF IP Address

When there is a need to change the PGW-C/SMF controlling certain PFCP sessions, e.g. when a partial or complete failure takes place, the PGW-C/SMF (either the PGW-C/SMF serving the PFCP sessions or another PGW-C/SMF in the same Set taking over the control of the PFCP sessions) may send a PFCP Session Set Modification Request message to the PGW-U/UPF(s) to request the PGW-U/UPF(s) to send subsequent PFCP Session Report Request messages to the alternative PGW-C/SMF (as indicated in the Alternative SMF IP Address IE) for the PFCP sessions which are associated with the FQ-CSID(s) or Group ID(s), or which have their CP F-SEID containing one of the PGW-C/SMF IP Address(es) as shown in Figure 31.6.4-1.

The PGW-C/SMF may instruct the UP function to move sessions associated with different PGW-C/SMF FQ-CSID(s), Group Ids or PGW-C/SMF IP addresses, to different PGW-C/SMF addresses.

Figure 31.6.4-1: PGW-C/SMF initiated PFCP Session Set Modification procedure

NOTE: This procedure enables a PGW-C/SMF from the same set to take the control of multiple PFCP sessions proactively, without causing massing signalling (per PFCP session) towards the PGW-U/UPF. The use of this procecure can reduce signalling latency and achieve a better load balancing among PGW-C/SMFs.

Annex A (informative):
Change history

Date

TSG #

TSG Doc.

CR

Rev

Cat

Subject/Comment

New

Apr 1999

Transferred to 3GPP CN1

CN#03

Approved at CN#03

3.0.0

CN#04

001

GPRS restoration procedures

3.1.0

CN#06

002r2

Authentication Enhancements

3.2.0

CN#06

003

Support of VLR and HLR Data Restoration procedures with LCS

3.2.0

CN#07

004

Support of VLR and HLR Data Restoration procedures with LCS

3.3.0

CN#08

005

Clarifications on GSM vs. UMTS specific parts

3.4.0

CN#11

Release 4 after CN#11

4.0.0

CN#16

007

Removal of an optional IMSI paging after SGSN restart

4.1.0

CN#16

Release 5 after CN#16

5.0.0

CN#22

011r1

Restoration of data in RA update

5.1.0

CN#23

008r3

Change of Restart Counter definition for enhanced GTP

6.0.0

CN#25

012

Error Indication during an ongoing MBMS data transfer

6.1.0

CN#25

013

Restoration of GSNs in MBMS

6.1.0

CT#30

0014

Incorrect References

6.2.0

CT#32

0019r1

Correction for Usage of Cancel Location for Supercharger

7.0.0

CT#40

0020r2

EPS Restoration

8.0.0

CT#41

0021r3

Moving restoration procedures from TS 23.060 into TS 23.007

8.1.0

CT#41

0023r2

Node Restart Restoration Procedures for PGW, SGW and MME

8.1.0

CT#42

0027r2

RNC failure aligns with TS23.060

8.2.0

CT#42

0028

Restoration procedures for SGs interface

8.2.0

CT#42

0033r5

Partial Failure Handling

8.2.0

CT#42

0037r1

PMIP Path management / Restoration Clean-up

8.2.0

CT#43

0030r5

Moving the description of the restoration procedures (from 29.274) to 23.007

8.3.0

CT#43

0038r4

Partial fault handling finalization

8.3.0

CT#44

0043r1

FQ-CSID corrections

8.4.0

CT#44

0047r1

SGSN and SGW handling in case RNC/BSC Failure (Iu mode) using S4

8.4.0

CT#44

0045r1

General on PMIP based restart procedure

9.0.0

CT#45

0065r1

Essential corrections to the partial failure support

9.1.0

0051

Removal of Editor’s note

0053r1

Restoration of data in MBMS GW

0058r1

Echo usage for GTPv2

0063r3

Error Indication cleanup

0064r4

Restoration of data in E-UTRAN

CT#46

0066

Paging signalling optimization after SGSN failure

9.2.0

0067

Paging signalling optimization after MME failure

0068

Error Indication for MBMS

0072r1

Removal of Editor’s Notes for Partial Failure

0078r1

Error Indication Handling for MBMS

0080

Alignment of eNodeB failure clause

0082r3

Alignment of RNC/BSC failure clause

CT#47

0091

Bulk Binding Revocation Indication

9.3.0

0082r2

Clarifications to eNodeB failure

0092r1

Reference corrections

0095r1

Restart counter correction

CT#48

0100r1

Essential correction to Error Indication message handling for the default bearer

9.4.0

0076r4

Cleanup of hanging PDN connections/bearers

0097r1

Failure of remote nodes

0107r1

Optimization on hanging PDN connection cleanup

10.0.0

CT#49

0115

Data Restoration for SMS

10.1.0

0117

GTP-C based restart procedures

0121

Partial Failure handling

CT#50

0135r1

Heartbeat Request

10.2.0

0129r1

ePDG Partial Failure

0133r1

Restoration of data in the ePDG

0131r1

Error Indication handling in PGW and ePDG

0132

ePDG/PGW restart and restoration

0130r1

PGW Restart Notification

0124

Essential correction to the MME and PGW restoration procedure

CT#51

0142r2

Timing for sending Downlink Data Notification as a result of the SGW having received an Error Indication message from the eNodeB/RNC

10.3.0

0151r1

Unclearness of Downlink Data Notification Handling at MME/S4 SGSN as a result of the SGW having received an Error Indication message from the eNodeB/RNC

0155

eNodeB failure

0154r1

RNC failure

0148r2

Error Indication in SGW

0145r1

Error Indication for SGW

0146r5

PCRF Failure and Restoration

0152r2

Handling of UE specific Error Indication over the PMIP

0156r5

MME/SGSN restart and restoration procedure

CT#52

0166r2

SGW behavior when it receives GTP error indication from S4-SGSN

10.4.0

0160r1

Fix wrong statement for the IMSI page in the Network triggered service restoration procedure

0164r2

Clarification on Network triggered service restoration procedure

0167r2

Gateway Control and QoS Policy Rules Provision Procedure handling at SGW

0161r1

Moving PCRF Restoration text under appropriate heading

0162

eNB Error Indication Handling

0163r3

MME/SGSN restart with ISR

CT#53

0169r2

Signalling path failure handling

10.5.0

0175r1

Downlink Data Notification Handling at MME/S4 SGSN

0170r1

User plane path failure handling

0171r1

PMIP alighnment for the network triggered service restoration procedure

CT#54

0183

Inter MME and intra SGW HO/TAU procedures

10.6.0

0176

NTSR with ISR active

0190

DDN message in the service restoration procedure

0185r2

Essential correction to Partial failure

CT#54

0178

FQ-CSID Reporting

11.0.0

0168r5

CS service restoration after MME failure

0177r1

PGW restoration

CT#55

0193r1

Error Indication Handling on S2a

11.1.0

0194r2

Restoration of data in the TWAN for S2a

0195r2

TWAN partial failure

0196r1

Restoration of data in the PGW for S2a

0198r1

Correction on the S4-SGSN failure

0199r1

S1 path failure handling

0201r2

IP Address of the node sending the recovery IE

CT#56

0191r1

SGW Restoration procedure

11.2.0

0204r1

Missing SGSN behavior in the PGW failure

0206r1

PGW triggered SGW restoration procedure

0208

Corrections to external resources cleanup upon SGW failure

CT#57

0210r2

Restoration of Data for VCSG

11.3.0

0211r1

Downlink Data Notification message handling in S4 SGSN

CT#58

0209r3

PCC and PMIP impacts for the SGW restoration procedure

11.4.0

0212

Corrections to reference titles

0215r1

Handling of emergency PDN connections during EPC node restoration

0216

Corrections to reference errors

0217r3

SGW failure when ISR is active

0214r4

Handling of VLR Failure without Restart

CT#58

0224r1

SGSN handling of VLR restart

11.5.0

0225r1

Fixing editor’s notes in SGW restoration procedure

0226r1

The inclusion of the MME/S4-SGSN identifier IE

CT#59

0218r1

Corrections to reference error for periodic location update timer

12.0.0

0220r1

MME/SGSN behaviour upon MBMS-GW restart

0221r1

eMBMS service restoration upon MCE failure or M3AP path failure

0222r1

eMBMS service restoration upon MME/SGSN restart

0223r2

Sm path failure handling

CT#60

0228

Trigger for re-establishing MBMS sessions upon an M3AP path recovery

12.1.0

0239r1

MME behaviour upon MBMS GW restart

0240r

SGSN behaviour upon MBMS GW restart

0237r1

BM-SC failure

0238r1

MBMS GW behaviour upon MME/SGSN restart

0236r2

MCE behavior on MME restart and MME behavior on MCE restart

0232r1

Contents of MBMS Session Start Request when re-establishing MBMS sessions

0231r2

SGmb path failure

0230r1

BM-SC behaviour upon MBMS GW restart

0229r1

Moving the control of an MBMS session to another MME

0241r2

Sn-path failure

0245r1

SGSN behaviour upon SGW restart

0234

Restoration Priority during SGW and PGW restoration procedures

0243r2

Delete Bearer Request triggered by PMIP error indication message

0242r1

Stop Paging Indication in service restoration procedure with ISR

CT#61

0246r1

MBMS Session Start Request received for an on-going MBMS bearer service

12.2.0

0247r1

MBMS Session duration

0248r1

BM-SC behaviour during SGmb path failure

0249r1

MCE behavior on MME restart

0250r1

Release of resources at old MME/SGSN during transient Sm path failure

0251r1

Separate Clause for MCE and RNC restoration functionality

0252r2

Correct S-GW behaviors when a peer P-GW failed

0253r1

Correct wrong NOTE reference

0255r2

Handling of VLR Failure without Restart for MO SMS

Sep 2013

Clause numbers correcterd in clause 17A.2. Style correction also in clause 27.2.2.2.

12.2.1

Dec 2013

0265r2

Correction of reference to Update Notifications for Proxy Mobile IPv6

12.3.0

0271r2

Error handling when the PCC rule is removed due to the S-GW restoration support

0256r1

Cause "GTP Resources Unavailable" handling at the SGSN

0258r6

Restoration of warning message delivery upon eNB failure/restart

0259

M3AP path recovery

0261r2

S4-SGSN procedure upon RNC and Iu path failure

0266r2

Non transient SGmb path failure

0267r2

Detection of peer MBMS node restart and SGmb path failure/recovery

0268r2

Non-transient SGi-mb path failure

Mar 2014

0263r6

SGW behaviour upon GTP Error indication

12.4.0

0277r1

Correct the PCRF procedure during the SGW restoration

0273r1

Update the reference of IETF draft Update Notifications for Proxy Mobile IPv6 to RFC 7077

0282r2

Handling of "GTP Resources Unavailable" cause in S4-SGSN

0275r1

PWS Restart Indication parameters

Jun 2014

0274r3

Sm path failure recovery

12.5.0

0283r1

SGmb path failure recovery

0288r1

M1 and/or M3/Iu resources modification during MBMS session re-establishment

0289

MCE Failure

0291r1

SGmb path failure

0284r1

Handling of E-RAB Release due to GTPU error indication for default bearer at MME

0296r2

Update SGW behaviours after receiving PMIP error indication

0285

PWS Restart Indication parameters

0286r2

HeNB ID verification in the PWS Restart Indication message

0287r2

Routing of PWS messages to HeNBs

0298r2

SGW restoration when S5 path failure occurs

0290

Restoring the (S)Gs associations during tracking/routing area update procedures

Sep 2014

0300r2

Correct procedure name for PDN connection deactivation

12.6.0

0301r3

Handling of GTP Error Indication for Dual connectivity

0302r2

Restoration for HSS Reset

0304r1

Remove Editor’s note for S5 path failure

Dec 2014

0307

Warning Area List in Write-Replace Warning Request during PWS restoration

12.7.0

0308r1

Serial Number in Write-Replace Warning Request during PWS restoration

0309

GCSE restoration procedures upon BM-SC restart

0310r1

GCSE restoration procedures upon GCS AS restart

0311r1

GCSE restoration procedures upon MB2-C path failure

0312

GCSE restoration procedures upon SGi-mb path failure

0314r1

GTP-C based restart procedures for HRPD

Mar 2015

0316r2

SGW restoration procedure in PMIP case

12.8.0

Mar 2015

0317r1

Deferring GBR bearers deactivation upon S1 Reset or S1AP path failure

13.0.0

Jun 2015

0318r1

MCE configuration update after an MBMS restoration

13.1.0

Sep 2015

0320r1

HSS Reset

13.2.0

Dec 2015

0321r2

Services restoration for UEs using extended idle mode DRX

13.3.0

0326r2

DTCI for restoration procedure

0323r1

Implementation mistake of CR 0309 and CR 0310

0324r2

HSS restart MONTE impacts

0325r2

SCEF restart and MONTE impacts

0327r2

SGW Restoration in Dedicated Core Network

Mar 2016

0329r2

HSS restart and resultant MONTE impacts

13.4.0

0330r2

Restart of SCEF

0331r1

Correct the partial failure handling on SGW

0332r1

S11-U Error Indication handling

0334r3

Behaviours upon receipt of unknown NIDD

0335r3

Enhance restoration procedure to be compatible with SCEF PDN connection and Attach without PDN connectivity

0336r2

Connection Resume procedure used during restoration

2016-06

CT#72

CP-160228

0337

3

MME handling of GTP Error Indication and MO-Data-Answer (failure)

13.5.0

2016-06

CT#72

CP-160231

0338

2

PGW restoration in NBIFOM case

13.5.0

2016-06

CT#72

CP-160234

0340

3

Restoration impact on the introduction of UE context retention at SCTP recovery

13.5.0

2016-06

CT#72

CP-160217

0341

1

Behaviours upon receipt of unknown NIDD (SGSN case)

14.0.0

2016-09

CT#73

CP-160422

0343

1

Failure case for NBIFOM

14.1.0

2017-03

CT#75

CP-170043

0344

1

Restoration Support for V2X Service

14.2.0

2017-03

CT#75

CP-170040

0345

1

Network triggered service restoration for PSM UE

14.2.0

2017-06

CT#76

CP-171036

0348

1

User Plane Path Failure with Control and User Plane Separation of SGW and PGW

14.3.0

2017-06

CT#76

CP-171023

0350

1

Service Restoration for UEs in extended DRX mode

14.3.0

2017-06

CT#76

CP-171036

0351

3

CUPS restoration procedures in SGW-C and SGW-U

14.3.0

2017-06

CT#76

CP-171036

0352

2

Partial failure handling for CUPS

14.3.0

2017-06

CT#76

CP-171036

0353

2

CUPS restoration procedures PGW-C and PGW-U

14.3.0

2017-06

CT#76

CP-171036

0354

1

CUPS restoration procedures

14.3.0

2017-12

CT#78

CP-173019

0355

–

Clarification on SGmb path failure

14.4.0

2018-06

–

–

–

–

Update to Rel-15 version (MCC)

15.0.0

2018-09

CT#81

CP-182079

0357

–

Corrections on CUPS restorations

15.1.0

2018-09

CT#81

CP-182078

0358

2

S1-U Path Failure Enhancement

15.1.0

2019-03

CT#83

CP-190040

0359

5

Recovery Time Stamp in PFCP

15.2.0

2019-06

CT#84

CP-191024

0363

2

Corrrections to the restoration procedures for PFCP entities

15.3.0

2019-09

CT#85

CP-192096

0364

–

Heartbeat procedure

15.4.0

2019-12

CT#86

CP-193041

0368

–

GTP Recovery Counter and GSN node behaviour

16.0.0

2019-12

CT#86

CP-193045

0365

1

PFCP Association Setup Request with same Node ID

16.0.0

2019-12

CT#86

CP-193045

0367

1

Reestablishment of PFCP sessions after a UP function restart

16.0.0

2020-03

CT#87e

CP-200038

0369

–

The Source IP Address in Heartbeat Request message

16.1.0

2020-03

CT#87e

CP-200038

0370

1

The Recovery Time Stamp in PFCP Session Establishment Request message

16.1.0

2020-03

CT#87e

CP-200021

0371

1

URCMP based restart procedures

16.1.0

2020-12

CT#90e

CP-203061

0372

3

Restoration of PDN connections after a PGW-C/SMF change

17.0.0

2021-06

CT#92e

CP-211043

0373

2

Restoration of PFCP sessions and PDN connections affected by a partial or complete failure

17.1.0

2021-06

CT#92e

CP-211043

0374

2

17.1.0

2021-09

CT#93e

CP-212033

0375

1

B

Restoration of PDN connections served by a combined SGW/PGW in a Set

17.2.0

2021-12

CT#94e

CP-213095

0376

–

B

SGW IP Address for a combined SGW/PGW/SMF

17.3.0

2022-03

CT#95e

CP-220033

0379

3

B

ePDG support of Restoration of PDN connections after a PGW-C/SMF change

17.4.0

2022-03

CT#95e

CP-220033

0380

1

B

New SGW IP Address when moving PDN connections for a combined SGW/PGW/SMF set

17.4.0

2022-03

CT#95e

CP-220037

0378

1

B

Detection and reporting of the restart of a GTP-U entity

17.4.0

2022-03

CT#95e

CP-220086

0381

1

B

Enhanced handling at user plane path failure

17.4.0

2022-03

Editorial corrections

17.4.1

2022-09

CT#97e

CP-222023

0382

–

B

Populating PGW Change Info during 5GS to EPS mobility procedure

18.0.0

2022-12

CT#98e

CP-223046

0384

1

F

PGW triggered PDN connection restoration

18.1.0