7.2.16 Update Bearer Response

29.2743GPP3GPP Evolved Packet System (EPS)Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C)Release 18Stage 3TS

An Update Bearer Response shall be sent from a MME/SGSN to a SGW and forwarded to the PGW, and from TWAN/ePDG to the PGW as a response to an Update Bearer Request message.

Table 7.2.16-1 specifies the presence requirements and the conditions of the IEs in the message.

Cause IE indicates if an EPS bearer has been modified in the MME/SGSN/TWAN/ePDG or not. The EPS Bearer has not been modified in the MME/SGSN/TWAN/ePDG if the Cause IE value differs from "Request accepted" or "Request accepted partially". Possible Cause values are specified in Table 8.4-1. Message specific cause values are:

  • "Request accepted".
  • "Request accepted partially"
  • "Context not found"
  • "Semantic error in the TFT operation".
  • "Syntactic error in the TFT operation".
  • "Semantic errors in packet filter(s)".
  • "Syntactic errors in packet filter(s)".

– "Denied in RAT".

– "UE refuses".

  • "Unable to page UE".
  • "UE not responding".
  • "Unable to page UE due to Suspension".
  • "Temporarily rejected due to handover/TAU/RAU procedure in progress".
  • "MME/SGSN refuses due to VPLMN Policy".
  • "UE is temporarily not reachable due to power saving"

Table 7.2.16-1: Information Elements in an Update Bearer Response

Information elements

P

Condition / Comment

IE Type

Ins.

Cause

M

Cause

0

Bearer Contexts

M

This IE shall contain all the bearer contexts included in the corresponding Update Bearer Request. Several IEs with this type and instance values shall be included as necessary to represent a list of Bearers.

Bearer Context

0

Protocol Configuration Options (PCO)

CO

An MME/SGSN shall include the PCO IE if such information was received from the UE.

If the SGW receives this IE, the SGW shall forward it to PGW on the S5/S8 interface.

PCO

0

Recovery

C

This IE shall be included on the S5/S8, S4/S11 and S2a/S2b interfaces if contacting the peer for the first time

Recovery

0

MME-FQ-CSID

C

This IE shall be included by MME on S11and shall be forwarded by SGW on S5/S8 according to the requirements in 3GPP TS 23.007 [17].

FQ-CSID

0

SGW-FQ-CSID

C

This IE shall be included by SGW on S5/S8 according to the requirements in 3GPP TS 23.007 [17].

FQ-CSID

1

ePDG-FQ-CSID

C

This IE shall be included by the ePDG on the S2b interface according to the requirements in 3GPP TS 23.007 [17].

FQ-CSID

2

TWAN-FQ-CSID

C

This IE shall be included by the TWAN on the S2a interface according to the requirements in 3GPP TS 23.007 [17].

FQ-CSID

3

Indication Flags

CO

This IE shall be included if any one of the applicable flags is set to 1.

Applicable flags:

  • Direct Tunnel Flag: This flag shall be set to 1 on the S4 interface, if Direct Tunnel is used.

Indication

0

UE Time Zone

O

This IE is optionally included by the MME on the S11 interface or by the SGSN on the S4 interface.

UE Time Zone

0

CO

The SGW shall forward this IE on the S5/S8 interface if the SGW receives it from the MME/SGSN.

CO

This IE shall be included by the TWAN on the S2a interface.

User Location Information (ULI)

CO

This IE shall be included by the MME on the S11 interface or by the SGSN on the S4 interface. The CGI/SAI shall be included by SGSN and the ECGI shall be included by MME.

See NOTE 1.

ULI

0

CO

The SGW shall forward this IE on the S5/S8 interface if it receives it from the MME/SGSN.

TWAN Identifier

CO

This IE shall be included by the TWAN on the S2a interface as specified in 3GPP TS 23.402 [45].

TWAN Identifier

0

MME/S4-SGSN’s Overload Control Information

O

During an overload condition, the MME/S4-SGSN may include this IE on the S11/S4 interface if the overload control feature is supported by the MME/S4-SGSN and is activated for the PLMN to which the PGW belongs (see clause 12.3.11).

When present, the MME/S4-SGSN shall provide only one instance of this IE, representing its overload information.

Overload Control Information

0

CO

If the SGW receives this IE and if it supports the overload control feature, it shall forward it to the PGW on the S5/S8 interface.

SGW’s Overload Control Information

O

During an overload condition, the SGW may include this IE over the S5/S8 interface if the overload control feature is supported by the SGW and is activated for the PLMN to which the PGW belongs (see clause 12.3.11).

When present, the SGW shall provide only one instance of this IE, representing its overload information.

Overload Control Information

1

Presence Reporting Area Information

CO

The MME/SGSN shall include this IE on S11/S4 if the PGW/PCRF/OCS has requested to start or modify reporting changes of UE presence in a Presence Reporting Area in the corresponding Update Bearer Request message and the MME/SGSN supports such reporting. The MME/SGSN shall then indicate whether the UE is inside or outside the newly started or modified Presence Reporting Area(s), or indicate that the Presence Reporting Area(s) is inactive.

The SGW shall include this IE on S5/S8 if it receives the Presence Reporting Area Information from the MME/SGSN.

Several IEs with the same type and instance value may be included as necessary to represent a list of Presence Reporting Area Information. One IE shall be included for each Presence Reporting Area newly started or modified.

Presence Reporting Area Information

0

MME/S4-SGSN Identifier

CO

If the overload control feature is supported by the MME/S4-SGSN and is activated for the PLMN to which the PGW belongs (see clause 12.3.11), the MME/S4-SGSN shall include this IE on the S11/S4 interface if the PGW has not been updated with the identity of the currently serving MME/S4-SGSN, i.e. if no other message carrying MME/S4-SGSN identity has been sent to the PGW during/after an inter-MME/S4-SGSN intra-SGW mobility procedure.

IP Address

0

CO

If the overload control feature is supported by the SGW, the SGW shall forward this IE on the S5/S8 interface.

TWAN/ePDG’s Overload Control Information

O

During an overload condition, the TWAN/ePDG may include this IE over the S2a/S2b interface if the overload control feature is supported by the TWAN/ePDG and is activated for the PLMN to which the PGW belongs (see clause 12.3.11).

When present, the TWAN/ePDG shall provide only one instance of this IE, representing its overload information.

Overload Control Information

2

WLAN Location Information

CO

The ePDG shall include this IE on the S2b interface if the WLAN Location Information is available.

TWAN Identifier

1

WLAN Location Timestamp

CO

The ePDG shall include this IE on the S2b interface, if the WLAN Location Timestamp is available.

TWAN Identifier Timestamp

1

UE Local IP Address

CO

The ePDG shall include this IE on the S2b interface.

IP Address

0

UE UDP Port

CO

The ePDG shall include this IE on the S2b interface if NAT is detected and UDP encapsulation is used.

Port Number

0

NBIFOM Container

CO

This IE shall be included on the S11/S4 or S2a/S2b interfaces if the MME/S4-SGSN or the TWAN/ePDG receives a NBIFOM Container from the UE as specified in 3GPP TS 24.161 73]. The Container Type shall be set to 4.

F-Container

0

CO

If the SGW receives a NBIFOM Container IE from the MME/S4-SGSN, the SGW shall forward it to the PGW on the S5/S8 interface.

UE TCP Port

CO

The ePDG shall include this IE on the S2b interface if NAT is detected and TCP encapsulation is used.

Port Number

1

PSCell ID

CO

The MME shall include this IE on the S11 interface, if it has received this information from the eNodeB.

PSCell ID

0

Private Extension

O

This IE may be sent on the S5/S8, S4/S11 and S2a/S2b interfaces.

Private Extension

VS

NOTE 1: In shared networks, when the message is sent from the VPLMN to the HPLMN, the PLMN ID that is communicated in this IE shall be that of the selected Core Network Operator for supporting UEs, or that of the allocated Core Network Operator for non-supporting UEs. As an exception, based on inter-operator roaming/sharing agreement, if the information on whether the UE is a supporting or non-supporting UE is available, the PLMN ID that is communicated to the HPLMN for non-supporting UEs shall be the Common PLMN ID.
In shared networks, when the MME/S4-SGSN and PGW pertain to the same PLMN, the Primary PLMN ID shall be communicated in the ECGI to the PGW, and the Common PLMN ID shall be communicated in SAI/CGI to the PGW, for both supporting and non-supporting UEs. The Core Network Operator PLMN ID (selected by the UE for supporting UEs or allocated by the network for non-supporting UEs) shall be communicated in the TAI, RAI, UCI and the Serving Network.
See clause 4.4 of 3GPP TS 23.251 [55].

Table 7.2.16-2: Bearer Context within Update Bearer Response

Octet 1

Bearer Context IE Type = 93 (decimal)

Octets 2 and 3

Length = n

Octet 4

Spare and Instance fields

Information elements

P

Condition / Comment

IE Type

Ins.

EPS Bearer ID

M

EBI

0

Cause

M

This IE Indicates if the bearer handling was successful, and if not, gives information on the reason.

Cause

0

S4-U SGSN F-TEID

C

This IE shall be included on the S4 interface when direct tunnel is not established. See NOTE 1.

F-TEID

0

S12 RNC F-TEID

C

This IE shall be included on the S4 interface when direct tunnel flag is set to 1. See NOTE 1.

F-TEID

1

Protocol Configuration Options (PCO)

CO

An MME/SGSN shall include the PCO IE if such information was received from the UE.

If the SGW receives this IE, the SGW shall forward it to PGW on the S5/S8 interface.

This bearer level IE takes precedence over the PCO IE in the message body if they both exist.

PCO

0

RAN/NAS Cause

CO

If the bearer modification failed, the MME shall include this IE on the S11 interface to indicate the RAN cause and/or the NAS cause of the bearer modification failure, if available and if this information is permitted to be sent to the PGW operator according to MME operator’s policy.
If both a RAN cause and a NAS cause are generated, then several IEs with the same type and instance value shall be included to represent a list of causes.

The SGW shall include this IE on the S5/S8 interface if it receives it from the MME.

RAN/NAS Cause

0

CO

If the bearer modification failed, the TWAN shall include this IE on the S2a interface to indicate the cause of the bearer modification failure, if available and if this information is permitted to be sent to the PGW operator according to the TWAN operator’s policy. When present, the IE shall be encoded as a Diameter or an ESM cause. See NOTE 2.

CO

If the bearer modification failed, the ePDG shall include this IE on the S2b interface to indicate the cause of the bearer modification failure, if available and if this information is permitted to be sent to the PGW operator according to the ePDG operator’s policy. When present, the IE shall be encoded as a Diameter or an IKEv2 cause. See NOTE 3.

Extended Protocol Configuration Options (ePCO)

CO

The MME shall include the ePCO IE if such information is received from the UE.

If the SGW receives this IE, the SGW shall forward it to PGW on the S5/S8 interface.

ePCO

0

NOTE 1: In some scenarios, the SGSN is unable to provide neither the S12 RNC F-TEID nor the S4-U SGSN F-TEID in the Update Bearer Response message, e.g. when Direct Tunnel is used in 3G and the UE is in IDLE mode, for a network requested user location retrieval procedure, the SGSN is unable to provide S12 RNC F-TEID. In those scenarios, the SGSN shall provide EBI(s) without S12 RNC F-TEID(s) and S4-U SGSN F-TEID. The SGW shall be able to handle these bearer context(s). However, in earlier releases this behaviour may not be supported by the SGW and hence for such an SGW, in order to be backward compatible, the SGSN shall provide EBI(s) together with either the S4-U SGSN F-TEID or the S12 RNC F-TEID.

NOTE 2: The TWAN does not exchange signalling with the 3GPP AAA Server nor with the UE in this procedure. The TWAN may include an internal failure cause for the bearer modification failure. The protocol type used to encode the internal failure cause is implementation specific.

NOTE 3: The ePDG does not exchange signalling with the 3GPP AAA Server in this procedure. The ePDG may include an internal failure cause for the bearer modification failure. The protocol type used to encode the internal failure cause is implementation specific.

Table 7.2.16-3: Overload Control Information within Update Bearer Response

Octet 1

Overload Control Information IE Type = 180 (decimal)

Octets 2 and 3

Length = n

Octet 4

Spare and Instance fields

Information elements

P

Condition / Comment

IE Type

Ins.

Overload Control Sequence Number

M

See clause 12.3.5.1.2.1 for the description and use of this parameter.

Sequence Number

0

Overload Reduction Metric

M

See clause 12.3.5.1.2.3 for the description and use of this parameter.

Metric

0

Period of Validity

M

See clause 12.3.5.1.2.2 for the description and use of this parameter.

This IE should be set to "0" if the "Overload Reduction Metric" is null. This IE shall be ignored by the receiver if the "Overload Reduction Metric" is null.

EPC Timer

0