ETSI TS 129 251 V15.3.0 (2019-10)

LTE; Gw and Gwn reference point for sponsored data connectivity (3GPP TS 29.251 version 15.3.0 Release 15)

RTS/TSGC-0329251vf30

General Information

• Status: Published
• Publication Date: 09-Oct-2019
• Technical Committee: 3GPP CT 3 - Interworking with external networks (formely CN3)
• Current Stage: 12 - Completion
• Completion Date: 10-Oct-2019

Standards Content (Sample)

ETSI TS 129 251 V15.3.0 (2019-10)






TECHNICAL SPECIFICATION
LTE;
Gw and Gwn reference point for sponsored data connectivity
(3GPP TS 29.251 version 15.3.0 Release 15)

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3GPP TS 29.251 version 15.3.0 Release 15 1 ETSI TS 129 251 V15.3.0 (2019-10)



Reference
RTS/TSGC-0329251vf30
Keywords
LTE
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3GPP TS 29.251 version 15.3.0 Release 15 2 ETSI TS 129 251 V15.3.0 (2019-10)
Intellectual Property Rights
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Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
The present document may refer to technical specifications or reports using their 3GPP identities. These shall be
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"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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3GPP TS 29.251 version 15.3.0 Release 15 3 ETSI TS 129 251 V15.3.0 (2019-10)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 5
1 Scope . 6
2 References . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 Gw reference point . 7
4.1 Overview . 7
4.2 Gw reference model . 7
4.3 Functional ele me nts . 8
4.3.1 PFDF . 8
4.3.2 PCEF . 8
4.4 Procedures over Gw reference point . 8
4.4.1 Request for PFDs ("Pull mode" and "Combination mode") . 8
4.4.2 Provisioning of PFDs ("Push mode"” and "Combination mode") . 9
5 Gwn reference point . 10
5.1 Overview . 10
5.2 Gwn reference model . 10
5.3 Functional ele me nts . 10
5.3.1 PFDF . 10
5.3.2 TDF . 10
5.4 Procedures over Gwn reference point . 11
6 Gw/Gwn protocol . 11
6.1 Introduction . 11
6.2 Transport layer . 11
6.3 Application delivery layer . 12
6.3.2 Resources and URI design . 12
6.3.2.1 General . 12
6.3.2.2 URI design for Pull mode . 13
6.3.2.3 URI design for Push mode . 13
6.3.3 HTTP request/response formats . 13
6.3.3.1 General . 13
6.3.3.2 GET /gwapplication/pfds/{application-identifier} . 14
6.3.3.3 GET /gwapplication/pfds?{query-parameters } . 15
6.3.3.4 GET /gwapplication/pfds . 17
6.3.3.5 POST /gwapplication/provisioning . 18
6.3.4 HTTP status codes . 20
6.3.5 Feature negotiation . 20
6.3.5.1 General . 20
6.3.5.2 HTTP custom headers . 21
6.3.5.2.1 3gpp-Optional-Features . 21
6.3.5.2.2 3gpp-Required-Features . 21
6.3.5.2.3 3gpp-Accepted-Features . 21
6.3.5.3 Precedence for HTTP custom headers . 22
6.4 Specific application communication . 22
6.4.1 General . 22
6.4.2 Content type . 22
6.4.3 JSON PFDs fields . 22
6.4.3.1 General . 22
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3GPP TS 29.251 version 15.3.0 Release 15 4 ETSI TS 129 251 V15.3.0 (2019-10)
6.4.3.2 application-identifier . 22
6.4.3.3 void . 23
6.4.3.4 caching-time . 23
6.4.3.5 pfds . 23
6.4.3.6 pfd-identifier . 23
6.4.3.7 flow-descriptions . 23
6.4.3.8 urls. 23
6.4.3.9 domain-names . 24
6.4.4 JSON provisioning fields . 24
6.4.4.1 General . 24
6.4.4.2 notification-flag . 24
6.4.4.3 removal-flag . 24
6.4.4.4 allowed-delay . 24
6.4.4.5 partial-flag . 24
6.4.5 JSON errors and informational response fields . 25
6.4.5.1 General . 25
6.4.5.2 error-tag . 25
6.4.6 JSON report fields . 25
6.4.6.1 General . 25
6.4.6.2 pfd-reports . 25
6.4.6.3 pfd-failure-code . 26
6.5 The discovery of PCEF/TDF and PFDF . 26
6.5.1 PCEF/TDF discovery . 26
6.5.2 PFDF discovery . 26
7 Secure communication . 26
Annex A (normative): JSON Schema . 27
A.1 PFDs schema . 27
A.2 Provisioning schema. 28
A.3 Error and Informational response schema . 29
Annex B (informative): Call Flows . 32
B.1 General . 32
B.2 Request for PFDs (“Pull mode”) . 32
B.3 Provisioning of PFDs (“Push mode”) . 32
B.4 Provisioning of PFDs by Push with Notifications . 33
Annex C (informative): Change history . 35
History . 36

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3GPP TS 29.251 version 15.3.0 Release 15 5 ETSI TS 129 251 V15.3.0 (2019-10)
Foreword
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This Technical Specification has been produced by the 3 Generation Partnership Project (3GPP).
The contents of the present document are subject to continuing work within the TSG and may change following formal
TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an
identifying change of release date and an increase in version number as follows:
Version x.y.z
where:
x the first digit:
1 presented to TSG for information;
2 presented to TSG for approval;
3 or greater indicates TSG approved document under change control.
y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,
updates, etc.
z the third digit is incremented when editorial only changes have been incorporated in the document.
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3GPP TS 29.251 version 15.3.0 Release 15 6 ETSI TS 129 251 V15.3.0 (2019-10)
1 Scope
The present document provides the stage 3 specification of the Gw and Gwn reference points. The functional
requirements and the stage 2 specifications of the Gw and Gwn reference points are specified in 3GPP TS 23.203 [2].
The Gw reference point lies between the Packet Flow Description Function (PFDF) and the Policy and Charging
Enforcement Function (PCEF). The Gwn reference point lies between the Packet Flow Description Function (PFDF)
and the Traffic Detection Function (TDF).
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or
non-specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including
a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same
Release as the present document.
[1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications".
[2] 3GPP TS 23.203: “Policy and charging control architecture”.
[3] 3GPP TS 29.213: "Policy and Charging Control signalling flows and QoS parameter mapping"
[4] 3GPP TS 23.682: "Architecture enhancements to facilitate communications with packet data
networks and applications".
[5] 3GPP TS 29.212: "Policy and Charging Control (PCC); Reference points".
[6] IETF RFC 793: "Transmission Control Protocol".
[7] Void.
[8] 3GPP TS 33.210: "3G security; Network Domain Security (NDS); IP network layer security".
[9] IETF RFC 2818: "HTTP Over TLS".
[10] IETF RFC 3986: "Uniform Resource Identifier (URI): Generic Syntax"
[11] IETF RFC 7159: "The JavaScript Object Notation (JSON) Data Interchange Format".
[12] IETF draft-newton-json-content-rules-09: "A Language for Rules Describing JSON Content".
NOTE: This individual draft will not further progress in IETF. It is available from the following link:
https://www.ietf.org/archive/id/draft-newton-json-content-rules-09.txt.
[13] IETF RFC 6733: "Diameter Base Protocol".
[14] 3GPP TS 29.250: "Nu reference point between SCEF and PFDF for sponsored data connectivity".
[15] 3GPP TS 29.155: "Traffic steering control; Representational state transfer (REST) over St
reference point".
[16] IETF RFC 7230: "Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing".
[17] IETF RFC 7231: "Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content".
[18] IETF RFC 7232: "Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests".
[19] IETF RFC 7233: "Hypertext Transfer Protocol (HTTP/1.1): Range Requests".
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3GPP TS 29.251 version 15.3.0 Release 15 7 ETSI TS 129 251 V15.3.0 (2019-10)
[20] IETF RFC 7234: "Hypertext Transfer Protocol (HTTP/1.1): Caching".
[21] IETF RFC 7235: "Hypertext Transfer Protocol (HTTP/1.1): Authentication".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A
term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].
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Packet Flow Description (PFD): A set of information enabling the detection of application traffic provided by a 3
party service provider (from 3GPP TS 23.203 [2]).
Pull mode: A mode used between the PCEF/TDF and the PFDF where the PFDs are sent by the PFDF at reception of
an HTTP request from the PCEF/TDF.
Push mode: A mode used between the PCEF/TDF and the PFDF where the PFDs and/or notification of PFD deletion
are sent by the PFDF in an HTTP request to the PCEF/TDF.
Combination mode: A mode used between the PCEF/TDF and the PFDF where both pull and push exist. This mode
allows the PFDF to send the PFDs at reception of an HTTP request from the PCEF/TDF and provision PFD changes
(creation/update/deletion) and/or notification of PFD creation/update/deletion in the HTTP request to the PCEF/TDF.
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An
abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in
3GPP TR 21.905 [1].
JSON JavaScript Object Notation
PCEF Policy and Charging Enforcement Function
PFD Packet Flow Description
PFDF Packet Flow Description Function
SCEF Service Capability Exposure Function
TDF Traffic Detection Function
4 Gw reference point
4.1 Overview
The Gw reference point is located between the Packet Flow Description Function (PFDF) and the Policy and Charging
Enforcement Function (PCEF). The Gw reference point is used for provisioning and removal of PFDs from the PFDF to
the PCEF and reporting the handling result of PFDs from the PCEF to the PFDF.
The stage 2 level requirements for the Gw reference point are defined in 3GPP TS 23.203 [2].
4.2 Gw reference model
The Gw reference point is defined between the PFDF and the PCEF. The relationships between the different functional
entities involved are depicted in figure 4.2.1. The overall PCC architecture is depicted in subclause 3a of
3GPP TS 29.213 [3].
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3GPP TS 29.251 version 15.3.0 Release 15 8 ETSI TS 129 251 V15.3.0 (2019-10)
Gw
PFDF
PCEF

Figure 4.2.1: Gw reference model
4.3 Functional elements
4.3.1 PFDF
The PFDF (Packet Flow Description Function) is a functional element which stores PFDs associated with application
identifier (s) and transfers them to the PCEF via Gw interface to enable the PCEF to perform accurate application
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detection when the PFDs are managed by a 3 party service provider.
The PFDF receives PFDs for the corresponding application identifier (s) from the SCEF as defined in
3GPP TS 23.682 [4]and 3GPP TS 29.250 [14].
4.3.2 PCEF
The PCEF (Policy and Charging Enforcement Function) funtionality defined in subclause 4.4.2 of 3GPP TS 29.212 [5]
shall be applied. In addition, the PCEF shall support the management of PFDs provisioned by the PFDF. The
application detection filter may be extended with the PFDs provided by the PFDF.
4.4 Procedures over Gw reference point
When the PFDF is deployed and the management of PFDs is supported by the PCEF, the mode of PFDs management
shall be consistently configured in one PLMN, it may be:
- Pull mode only, or
- Push mode only, or
- Combination mode.
4.4.1 Request for PFDs ("Pull mode" and "Combination mode")
At the time a PCC Rule with an application identifier for which PFDs provisioned by the PFDF are not available is
activated or provisioned, or when the caching timer for an application identifier elapses and a PCC Rule for the
application identifier is still active, the PCEF shall request all PFDs for the application identifier from the PFDF.
The PCEF shall send an HTTP GET message to the PFDF to retrieve the PFDs for one or more application identifier(s)
as defined in subclauses 6.3.3.2, 6.3.3.3 and 6.3.3.4.
Upon receipt of the HTTP request for the pull operation, the PFDF shall respond to the PCEF indicating whether the
pull operation was successful or not by using one of the HTTP status codes; if the pull operation is successful, the
PFDF :
- shall provide the PFDs of the specified application identifier(s) from the request within the body of the HTTP
response; and
- if there are caching time value(s) configured for any of the specified application identifier(s), shall set the
caching-time to the caching time value(s) for those application identifier(s) in the body of the HTTP response.
The PCEF shall install, update or remove the received PFD(s) for the application identifier(s).
The PCEF shall also for each application identifier start a caching timer with a value
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3GPP TS 29.251 version 15.3.0 Release 15 9 ETSI TS 129 251 V15.3.0 (2019-10)
- according to the received caching time value for that application identifier, if such a value is received for that
application identifier; or
- otherwise with a default caching time value configured in the PCEF.
NOTE 1: The PCEF(s) and the PFDF(s) within an operator network are configured with the same default caching
time value to be applied for all application identifiers.
NOTE 2: In the combination mode, the HTTP POST message from the PFDF does not impact the running caching
timer of an application identifier.
When the PCEF removes the last PCC rule that refers to the corresponding application identifier, or when the caching
timer expires and no PCC rule refers to the application identifier, the PCEF may remove the PFD(s) related with the
application identifier.
The PFDs retrieved from PFDF take precedence over any PFDs pre-configured in the PCEF. If all PFDs retrieved from
the PFDF are removed for an application identifier, the pre-configured PFDs shall be applied again for the application
identifier.
4.4.2 Provisioning of PFDs ("Push mode"” and "Combination mode")
The PFDF may create, update or remove one or multiple PFDs associated with application identifier(s) to the PCEF.
When the request for creation, update, or removal for an application identifier(s) is received from the SCEF, for the
Push mode, the PFDF shall for each PCEF it serves:
- immediately send to the PCEF an HTTP POST message including the provisioned changes of one or more
application identifiers as specified in subclause 6.3.3.5, or
- wait for a period shorter than the allowed delay ( e.g.to aggregate all the PFDs for several application) , then
send t
...