ETSI TS 129 508 V15.6.0 (2020-01)

5G; 5G System; Session Management Event Exposure Service; Stage 3 (3GPP TS 29.508 version 15.6.0 Release 15)

RTS/TSGC-0329508vf60

General Information

• Status: Published
• Publication Date: 14-Jan-2020
• Technical Committee: 3GPP CT 3 - Interworking with external networks (formely CN3)
• Current Stage: 12 - Completion
• Completion Date: 15-Jan-2020

Standards Content (Sample)

ETSI TS 129 508 V15.6.0 (2020-01)






TECHNICAL SPECIFICATION
5G;
5G System;
Session Management Event Exposure Service;
Stage 3
(3GPP TS 29.508 version 15.6.0 Release 15)



---------------------- Page: 1 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 1 ETSI TS 129 508 V15.6.0 (2020-01)



Reference
RTS/TSGC-0329508vf60
Keywords
5G
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2020.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners.
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 2 ETSI TS 129 508 V15.6.0 (2020-01)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
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
interpreted as being references to the corresponding ETSI deliverables.
The cross reference between 3GPP and ETSI identities can be found under http://webapp.etsi.org/key/queryform.asp.
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

---------------------- Page: 3 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 3 ETSI TS 129 508 V15.6.0 (2020-01)
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 Session Management Event Exposure Service . 7
4.1 Service Description . 7
4.1.1 Overview . 7
4.1.2 Service Architecture . 8
4.1.3 Network Functions . 9
4.1.3.1 Session Management Function (SMF) . 9
4.1.3.2 NF Service Consumers . 9
4.2 Service Operations . 9
4.2.1 Introduction. 9
4.2.2 Nsmf_EventExposure_Notify Service Operation . 9
4.2.2.1 General . 9
4.2.2.2 Notification about subscribed events . 10
4.2.3 Nsmf_EventExposure_Subscribe Service Operation . 12
4.2.3.1 General . 12
4.2.3.2 Creating a new subscription . 12
4.2.3.3 Modifying an existing subscription . 13
4.2.4 Nsmf_EventExposure_UnSubscribe Service Operation . 14
4.2.4.1 General . 14
4.2.4.2 Unsubscription from event notifications . 14
5 Nsmf_EventExposure API . 15
5.1 Introduction . 15
5.2 Usage of HTTP . 15
5.2.1 General . 15
5.2.2 HTTP standard headers . 16
5.2.2.1 General . 16
5.2.2.2 Content type . 16
5.2.3 HTTP custom headers . 16
5.3 Resources . 16
5.3.1 Resource Structure . 16
5.3.2 Resource: SMF Notification Subscriptions . 17
5.3.2.1 Description . 17
5.3.2.2 Resource definition . 17
5.3.2.3 Resource Standard Methods . 17
5.3.2.3.1 POST . 17
5.3.2.4 Resource Custom Operations . 17
5.3.3 Resource: Individual SMF Notification Subscription . 17
5.3.3.1 Description . 17
5.3.3.2 Resource definition . 18
5.3.3.3 Resource Standard Methods . 18
5.3.3.3.1 GET . 18
5.3.3.3.2 PUT . 18
5.3.3.3.3 DELETE . 19
5.3.3.4 Resource Custom Operations . 19
5.4 Custom Operations without associated resources. 19
ETSI

---------------------- Page: 4 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 4 ETSI TS 129 508 V15.6.0 (2020-01)
5.5 Notifications . 20
5.5.1 General . 20
5.5.2 Event Notification . 20
5.5.2.1 Description . 20
5.5.2.2 Target URI . 20
5.5.2.3 Standard Methods . 20
5.5.2.3.1 POST . 20
5.6 Data Model . 21
5.6.1 General . 21
5.6.2 Structured data types . 21
5.6.2.1 Introduction . 21
5.6.2.2 Type NsmfEventExposure . 22
5.6.2.3 Type NsmfEventExposureNotification . 24
5.6.2.4 Type EventSubscription . 24
5.6.2.5 Type EventNotification . 25
5.6.3 Simple data types and enumerations . 27
5.6.3.1 Introduction . 27
5.6.3.2 Simple data types . 27
5.6.3.3 Enumeration: SmfEvent . 27
5.6.3.4 Enumeration: NotificationMethod . 27
5.7 Error handling . 28
5.7.1 General . 28
5.7.2 Protocol Errors . 28
5.7.3 Application Errors . 28
5.8 Feature negotiation . 28
5.9 Security . 28
Annex A (normative): OpenAPI specification . 29
A.1 General . 29
A.2 Nsmf_EventExposure API . 29
Annex B (informative): Change history . 35
History . 36

ETSI

---------------------- Page: 5 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 5 ETSI TS 129 508 V15.6.0 (2020-01)
Foreword
rd
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.
ETSI

---------------------- Page: 6 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 6 ETSI TS 129 508 V15.6.0 (2020-01)
1 Scope
The present specification provides the stage 3 definition of the Session Management Event Exposure Service
(Nsmf_EventExposure) of the 5G System.
The stage 2 definition and procedures of the Session Management Event Exposure Service are contained in
3GPP TS 23.502 [3] and 3GPP TS 23.503 [6]. The 5G System Architecture is defined in 3GPP TS 23.501 [2].
Stage 3 call flows for policy and charging control use cases are provided in 3GPP TS 29.513 [7].
The Technical Realization of the Service Based Architecture and the Principles and Guidelines for Services Definition
of the 5G System are specified in 3GPP TS 29.500 [4] and 3GPP TS 29.501 [5].
The Session Management Event Exposure Service is provided by the Session Management Function (SMF). This
service exposes events related to PDU Sessions observed at the SMF.
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 23.501: "System Architecture for the 5G System; Stage 2".
[3] 3GPP TS 23.502: "Procedures for the 5G System; Stage 2".
[4] 3GPP TS 29.500: "5G System; Technical Realization of Service Based Architecture; Stage 3".
[5] 3GPP TS 29.501: "5G System; Principles and Guidelines for Services Definition; Stage 3".
[6] 3GPP TS 23.503: "Policy and Charging Control Framework for the 5G System; Stage 2".
[7] 3GPP TS 29.513: "5G System; Policy and Charging Control signalling flows and QoS parameter
mapping; Stage 3".
[8] IETF RFC 7540: "Hypertext Transfer Protocol Version 2 (HTTP/2)".
[9] IETF RFC 8259: "The JavaScript Object Notation (JSON) Data Interchange Format".
[10] OpenAPI, "OpenAPI 3.0.0 Specification", https://github.com/OAI/OpenAPI-
Specification/blob/master/versions/3.0.0.md.
[11] 3GPP TS 29.571: "5G System; Common Data Types for Service Based Interfaces Stage 3".
[12] 3GPP TS 29.510: "5G System; Network Function Repository Services; Stage 3".
[13] 3GPP TS 29.518: "5G System; Access and Mobility Management Services; Stage 3".
[14] 3GPP TS 29.512: "5G System; Session Management Policy Control Service; Stage 3".
[15] 3GPP TS 33.501: "Security architecture and procedures for 5G system".
[16] IETF RFC 6749: "The OAuth 2.0 Authorization Framework".
ETSI

---------------------- Page: 7 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 7 ETSI TS 129 508 V15.6.0 (2020-01)
[18] IETF RFC 7807: "Problem Details for HTTP APIs".
[19] 3GPP TR 21.900: "Technical Specification Group working methods".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in 3GPP 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
3GPP TR 21.905 [1].
3.2 Abbreviations
For the purposes of the present document, the abbreviations given in 3GPP 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].
AF Application Function
AMBR Aggregate Maximum Bit Rate
AMF Access and Mobility Management Function
API Application Programming Interface
DNAI DN Access Identifier
DNN Data Network Name
GUAMI Globally Unique AMF Identifier
HTTP Hypertext Transfer Protocol
JSON JavaScript Object Notation
NEF Network Exposure Function
NF Network Function
NRF Network Repository Function
SMF Session Management Function
SUPI Subscription Permanent Identifier
PCF Policy Control Function
PRA Presence Reporting Area
UPF User Plane Function
4 Session Management Event Exposure Service
4.1 Service Description
4.1.1 Overview
The Session Management Event Exposure Service, as defined in 3GPP TS 23.502 [3] and 3GPP TS 23.503 [6], is
provided by the Session Management Function (SMF).
This service:
- allows consumer NFs to subscribe and unsubscribe for events on a PDU session; and
- notifies consumer NFs with a corresponding subscription about observed events on the PDU session.
The types of observed events include:
- UP path change (e,g, addition and/or removal of PDU session anchor);
- access type change;
ETSI

---------------------- Page: 8 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 8 ETSI TS 129 508 V15.6.0 (2020-01)
- PLMN change;
- PDU session release; and
- UE IP address/prefix change.
4.1.2 Service Architecture
The 5G System Architecture is defined in 3GPP TS 23.501 [2]. The Policy and Charging related 5G architecture is also
described in 3GPP TS 29.513 [7].
The Session Management Event Exposure Service (Nsmf_EventExposure) is part of the Nsmf service-based interface
exhibited by the Session Management Function (SMF),
Known consumer of the Nsmf_EventExposure service are:
- Network Exposure Function (NEF)
- Access and Mobility Management Function (AMF).
- Application Function (AF)
The PCF accesses the Session Management Event Exposure Service at the SMF via the N7 Reference point.
NOTE: The PCF can implicitly subscribe on behalf of the AF and NEF to the UP_PATH_CH event by including
the information on AF subscription within the PCC rule.
The AMF accesses the Session Management Event Exposure Service at the SMF via the N11 Reference point.
SMF
Nsmf
Nsmf_EventExposure
Application
AMF NEF
PCF
Function

Figure 4.1.2-1: Reference Architecture for the Nsmf_EventExposure Service; SBI representation
SMF
N11 N29
AMF NEF
AF

Figure 4.1.2-2: Reference Architecture for the Nsmf_EventExposure Service: reference point
representation
ETSI

---------------------- Page: 9 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 9 ETSI TS 129 508 V15.6.0 (2020-01)
4.1.3 Network Functions
4.1.3.1 Session Management Function (SMF)
The Session Management function (SMF) provides:
- Session Management e.g. Session establishment, modification and release;
- UE IP address allocation & management;
- Selection and control of UP function;
- Termination of interfaces towards Policy control functions; and
- Control part of policy enforcement and QoS.
4.1.3.2 NF Service Consumers
The Network Exposure Function (NEF);
- provides a means to securely expose the services and capabilities provided by 3GPP network functions for e.g.
3rd parties or internal exposure.
The Access and Mobility Management function (AMF) provides:
- Registration management;
- Connection management;
- Reachability management; and
- Mobility Management.
The Application Function (AF)
- interacts with the 3GPP Core Network to provide services.
4.2 Service Operations
4.2.1 Introduction
Table 4.2.1-1: Operations of the Nsmf_EventExposure Service
Service operation name Description Initiated by
Notify Report UE PDU session related event(s) to the NF SMF
service consumer which has subscribed to the
event report service.
Subscribe This service operation is used by an NF service NF service consumer
consumer to subscribe for event notifications on a
specified PDU session, or for all PDU Sessions of
one UE, a group of UE(s) or any UE, or to modify a
subscription.
UnSubscribe This service operation is used by an NF service NF service consumer
consumer to unsubscribe from event notifications.

4.2.2 Nsmf_EventExposure_Notify Service Operation
4.2.2.1 General
The Nsmf_EventExposure_Notify service operation enables notification to NF service consumers that the previously
subscribed event on the related PDU session occurred.
ETSI

---------------------- Page: 10 ----------------------
3GPP TS 29.508 version 15.6.0 Release 15 10 ETSI TS 129 508 V15.6.0 (2020-01)
The following procedure using the Nsmf_EventExposure_Notify service operation is supported:
- notification about subscribed events.
4.2.2.2 Notification about subscribed events
Figure 4.2.2.2-1 illustrates the notification about subscribed events.

Figure 4.2.2.2-1: Notification about subscribed events
If the SMF observes PDU Session related event(s) for which an NF service consumer has subscribed to, the SMF shall
send an HTTP POST request with "{notifUri}" as previously provided by the NF service consumer within the
corresponding subscription as URI and NsmfEventExposureNotification data structure as request body that shall
include:
- Notification correlation ID provided by the NF service consumer during the subscription, or as provided by the
PCF for implicit subscription of UP path change as defined in subclause 4.2.6.2.6.2 of 3GPP TS 29.512 [14], as
"notifId" attribute; and
- information about the observed event(s) within the "eventNotifs" attribute that shall contain for each observed
event an "EventNotification" data structure that shall include:
1. the Event Trigger as "event" attribute;
2. for a UP path change notification:
a) type of notification ("EARLY" or "LATE") as "dnaiChgType" attribute;
b) source DNAI and/or target DNAI as "sourceDnai" attribute and "targetDnai" attribute if DNAI is
changed, respectively (NOTE 3); and
c) if the PDU Session type is IP, for the source DNAI IP address/prefix of the UE as "sourceUeIpv4Addr"
attribute or "sourceUeIpv6Prefix" attribute; and
d) if the PDU Session type is IP, for the target DNAI IP address/prefix of the UE as "targetUeIpv4Addr"
attribute or "targetUeIpv6Prefix" attribute;
e) if available (NOTE 3), for the source DNAI, N6 traffic routing information related to the UE as
"sourceTraRouting" attribute;
f) if available (NOTE 3), for the target DNAI, N6 traffic routing information related to the UE as
"targetTraRouting" attribute; and
g) if the PDU Session type is Ethernet, the MAC address of the UE in the "ueMac" attribute;
NOTE 1: UP path change notification, i.e. DNAI change notification and/or N6 traffic routing information change
notification, can be the result of an implicit subscription of the PC
...