Content for TS 29.128 Word version: 18.0.0

1 Scope p. 7

The present document describes the Diameter-based interfaces between the SCEF/IWK-SCEF and other network entities such as MME/SGSN for the Architecture enhancements to facilitate communications with packet data networks and applications.

In particular, this document specifies the T6a interface between the MME and the SCEF, the T6ai interface between the MME and the IWK-SCEF, the T6b interface between the SGSN and the SCEF, the T6bi interface between the SGSN and the SCEF and the T7 interface between the SCEF and the IWK-SCEF. The procedures over those interfaces are defined in TS 23.682.

2 References p. 7

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]

TR 21.905: "Vocabulary for 3GPP Specifications".

[2]

TS 23.682: "Architecture enhancements to facilitate communications with packet data networks and applications ".

[3] Void.

[4]

TS 29.229: "Cx and Dx interfaces based on the Diameter protocol; protocol details ".

[5]

TS 29.336: "Home Subscriber Server (HSS) diameter interfaces for interworking with packet data networks and applications".

[6]

TS 29.228: "IP multimedia (IM) Subsystem Cx Interface; Signalling flows and Message Elements".

[7]

RFC 4960: "Stream Control Transport Protocol".

[8]

RFC 5234: "Augmented BNF for Syntax Specifications: ABNF".

[9]

RFC 7683: "Diameter Overload Indication Conveyance".

[10]

TS 29.212: "Policy and Charging Control (PCC); Reference points".

[11]

TS 25.413: "UTRAN Iu interface Radio Access Network Application Part (RANAP) signalling".

[12]

TS 24.008: "Mobile Radio Interface Layer 3 specification; Core Network Protocols; Stage 3".

[13]

TS 36.413: "Evolved Universal Terrestrial Radio Access Network (E-UTRAN); S1 Application Protocol (S1AP)".

[14]

TS 48.018: "General Packet Radio Service (GPRS); Base Station System (BSS) - Serving GPRS Support Node (SGSN); BSS GPRS protocol (BSSGP)".

[15]

RFC 7944: "Diameter Routing Message Priority".

[16]

TS 29.272: "Mobility Management Entity (MME) and Serving GPRS Support Node (SGSN) related interfaces based on Diameter protocol".

[17]

TS 29.329: "Sh Interface based on the Diameter protocol; Protocol details".

[18] Void.

[19]

TS 23.007: "Restoration procedures".

[20]

TS 32.299: "Telecommunication management; Charging management; Diameter charging applications".

[21]

RFC 5778: "Diameter Mobile IPv6: Support for Home Agent to Diameter Server Interaction".

[22]

TS 32.299: "Telecommunication management; Charging management; Diameter charging applications".

[23]

TS 32.253: "Telecommunication management; Charging management; Control Plane (CP) data transfer domain charging".

[24]

TS 23.003: "Numbering, addressing and identification".

[25]

TS 23.401: "GPRS enhancements for E-UTRAN access".

[26]

TS 29.172: "Location Services (LCS); Evolved Packet Core (EPC) LCS Protocol (ELP) between the Gateway Mobile Location Centre (GMLC) and the Mobile Management Entity (MME); SLg interface".

[27]

TS 29.338: "Diameter based protocols to support SMS capable MMEs".

[28]

TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3".

[29]

TS 29.061: "Interworking between the Public Land Mobile Network (PLMN) supporting packet based services and Packet Data Networks (PDN)".

[30]

TS 32.298: "Telecommunication Management; Charging Management; Charging Data Record (CDR) parameter description".

[31]

RFC 8583: "Diameter Load Information Conveyance".

[32]

RFC 6733: "Diameter Base Protocol".

[33]

TS 29.274: "Evolved General Packet Radio Service (GPRS) Tunnelling Protocol for Control plane (GTPv2-C)".

3 Definitions and abbreviations p. 9

3.1 Definitions p. 9

For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply.

3.2 Abbreviations p. 9

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.

DRMP

Diameter Routing Message Priority

DSCP

Differentiated Services Code Point

SCEF

Service Capability Exposure Function

IWK-SCEF

Interworking - SCEF

4 General Description p. 9

4.1 Introduction p. 9

The T6a/b reference point between the MME/SGSN and the SCEF, the T6ai/bi reference point between the MME/SGSN in the VPLMN and the IWK-SCEF and the T7 reference point between the IWK-SCEF and the SCEF are defined in the TS 23.682.

This document describes the Diameter-based T6a/b, T6ai/bi and T7 related procedures, message parameters and protocol specification.

An excerpt of the 3GPP Architecture for the enhancements to facilitate communications with packet data networks and applications, as defined in TS 23.682 is shown in Figure 4.1-1, where the relevant interfaces towards the SCEF/IWK-SCEF are highlighted.

Reproduction of 3GPP TS 29.128, Fig. 4.1-1: 3GPP Architecture for the enhancements to facilitate communications with packet data networks and applications

Figure 4.1-1: 3GPP Architecture for the enhancements to facilitate communications with packet data networks and applications

In this architecture, the T6a/b reference point connects the MME/SGSN with the SCEF.

The T6a/b interface shall allow the SCEF:

to receive reports of the monitoring events from the MME/SGSN configured via an HSS;
to configure the monitoring events at an MME/SGSN which are not UE related in the non roaming cases;
to manage a connection between the MME and the SCEF on T6a;
to send MT data on T6a;
to receive MO data on T6a.

The T6ai/bi reference point connects the MME/SGSN with the IWK-SCEF in the visited network, if the IWK-SCEF is deployed.

The T6ai/bi interface shall allow the IWK-SCEF to:

to receive configuration of the monitoring events from the MME or the SGSN and perform a filtering of the services which are allowed for this subscriber in this visited network based on roaming policies;
to receive reports of the monitoring events from the MME/SGSN that are configured via an HSS, perform a filtering and forward them to the SCEF (in the home network which has configured the event) via the T7 reference point;
to receive MO data on T6ai/bi and forward them to the SCEF;
to receive MT data and forward them to the MME on T6ai/bi;
to manage a connection between MME/SGSN and IWK-SCEF on T6ai/bi and forward connection management commands to the SCEF.

The T7 reference point connects the IWK-SCEF in the visited network with the SCEF in the home network.

The T7 interface shall allow the IWK-SCEF to:

to forward reports received on T6ai/bi to the SCEF indicated in the event report received on T6ai/T6bi;
to receive MO data on T6ai/bi and forward them to the SCEF on T7;
to receive MT data on T7 and forward them to the MME/SGSN;
to manage connection between the SCEF and the IWK-SCEF on T7 and forward connection management commands to the MME/SGSN.