ETSI TS 124 371 V15.3.0 (2021-01)

Universal Mobile Telecommunications System (UMTS); LTE; Web Real-Time Communications (WebRTC) access to the IP Multimedia (IM) Core Network (CN) subsystem (IMS); Stage 3; Protocol specification (3GPP TS 24.371 version 15.3.0 Release 15)

RTS/TSGC-0124371vf30

General Information

• Status: Not Published
• Technical Committee: 3GPP CT 1 - MM/CC/SM [lu] (formely CN1)
• Current Stage: 12 - Completion
• Completion Date: 14-Jan-2021

Standards Content (Sample)

ETSI TS 124 371 V15.3.0 (2021-01)






TECHNICAL SPECIFICATION
Universal Mobile Telecommunications System (UMTS);
LTE;
Web Real-Time Communications (WebRTC)
access to the IP Multimedia (IM) Core Network (CN)
subsystem (IMS);
Stage 3;
Protocol specification
(3GPP TS 24.371 version 15.3.0 Release 15)

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3GPP TS 24.371 version 15.3.0 Release 15 1 ETSI TS 124 371 V15.3.0 (2021-01)



Reference
RTS/TSGC-0124371vf30
Keywords
LTE,UMTS
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3GPP TS 24.371 version 15.3.0 Release 15 2 ETSI TS 124 371 V15.3.0 (2021-01)
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
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Legal Notice
This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).
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Modal verbs terminology
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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 24.371 version 15.3.0 Release 15 3 ETSI TS 124 371 V15.3.0 (2021-01)
Contents
Intellectual Property Rights . 2
Legal Notice . 2
Modal verbs terminology . 2
Foreword . 6
1 Scope . 7
2 References . 7
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 9
4 Overview of WebRTC access to IMS . 10
4.1 General . 10
5 Functional entities . 10
5.1 General . 10
5.2 WIC (WebRTC IMS Client) . 10
5.3 WWSF (WebRTC Web Server Function) . 11
5.4 WAF (WebRTC Authorisation Function) . 11
5.5 eP-CSCF (P-CSCF enhanced for WebRTC) . 11
5.6 eIMS-AGW (IMS Access Gateway enhanced for WebRTC) . 11
5A Data transport . 11
5A.1 General . 11
5A.2 UE . 11
5A.3 WWSF (WebRTC Web Server Function) . 11
5A.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 12
5B Data framing and securing . 12
5B.1 General . 12
5B.2 UE . 12
5B.3 WWSF (WebRTC Web Server Function) . 12
5B.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 12
5C Data formats . 13
5C.1 General . 13
5C.2 UE . 13
5C.3 WWSF (WebRTC Web Server Function) . 13
5C.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 13
5D Connection management . 14
5D.1 General . 14
5D.2 UE . 14
5D.3 WWSF (WebRTC Web Server Function) . 14
5D.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 14
5E Presentation and control . 14
5E.1 General . 14
5E.2 UE . 15
5E.3 WWSF (WebRTC Web Server Function) . 15
5E.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 15
5F Local system support functions . 15
5F.1 General . 15
5F.2 UE . 15
5F.3 WWSF (WebRTC Web Server Function) . 15
5F.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 15
6 Registration and authentication . 15
ETSI

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3GPP TS 24.371 version 15.3.0 Release 15 4 ETSI TS 124 371 V15.3.0 (2021-01)
6.1 General . 15
6.2 WIC (WebRTC IMS Client) . 16
6.2.1 WIC registration of individual Public User Identity using IMS authentication . 16
6.2.1.1 General . 16
6.2.1.2 W2 using SIP Digest credentials . 16
6.2.1.3 W2 using IMS-AKA . 17
6.2.2 WIC registration of individual public user identity based on web authentication . 17
6.2.3 WIC registration of individual public user identity from a pool of public user identities. 17
6.3 WWSF (WebRTC Web Server Function) and WAF (WebRTC Authorisation Function) . 18
6.3.1 WIC registration of individual public user identity using web credentials . 18
6.3.2 WIC registration of individual public user identity from a pool of public user identities. 18
6.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 18
6.4.1 WIC registration of individual Public User Identity using IMS authentication . 18
6.4.1.1 Determination of IMS authentication mechanism . 18
6.4.1.2 W2 using SIP Digest credentials . 18
6.4.1.3 W2 using IMS-AKA . 19
6.4.2 WIC registration of individual public user identity using web credentials . 19
6.4.3 WIC registration of individual public user identity from a pool of public user identities. 20
6A Deregistration . 20
6A.1 General . 20
6A.2 WIC (WebRTC IMS Client) . 21
6A.3 eP-CSCF (P-CSCF enhanced for WebRTC) . 21
7 Call origination and termination . 21
7.1 General . 21
7.2 WIC (WebRTC IMS Client) . 21
7.2.1 General . 21
7.2.2 WIC originating call . 22
7.2.3 WIC terminating call . 22
7.2.4 WIC emergency call . 22
7.3 WWSF (WebRTC Web Server Function) . 23
7.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 23
7.4.1 General . 23
7.4.2 WIC originating call . 23
7.4.3 WIC terminating call . 24
7.4.4 WIC emergency call . 25
7.4.5 Media optimization procedure . 25
7.4.5.1 WIC originating call . 25
7.4.5.2 WIC terminating call . 27
8 Data channel open and close . 30
8.1 General . 30
8.2 WIC (WebRTC IMS Client) . 30
8.2.1 General . 30
8.2.2 WIC originating call . 30
8.2.3 WIC terminating call . 31
8.3 WWSF (WebRTC Web Server Function) . 31
8.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 31
8.4.1 General . 31
8.4.2 WIC originating call . 31
8.4.3 WIC terminating call . 32
9 Call modification . 33
10 IP multimedia application support in the IM CN subsystem using webRTC . 33
10.1 General . 33
10.2 Access to MMTel and supplementary services using webRTC . 33
10.2.1 General . 33
10.2.2 WIC (WebRTC IMS Client) . 33
10.2.2.1 SIP based protocol used by the WIC . 33
10.2.2.2 non-SIP based protocol used by the WIC . 33
10.2.3 WWSF (WebRTC Web Server Function) . 33
10.2.4 eP-CSCF (P-CSCF enhanced for WebRTC) . 33
ETSI

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3GPP TS 24.371 version 15.3.0 Release 15 5 ETSI TS 124 371 V15.3.0 (2021-01)
Annex A (informative): Example signalling flows . 34
A.1 Scope of signalling flows . 34
A.2 Void . 34
A.3 Signalling flows for registration . 34
A.3.1 Void . 34
A.3.2 WIC registration of individual public user identity based on web authentication . 34
A.3.3 Void . 36
A.4 Void . 36
A.5 Void . 36
Annex B (informative): Change history . 37
History . 39

ETSI

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3GPP TS 24.371 version 15.3.0 Release 15 6 ETSI TS 124 371 V15.3.0 (2021-01)
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

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3GPP TS 24.371 version 15.3.0 Release 15 7 ETSI TS 124 371 V15.3.0 (2021-01)
1 Scope
The present document provides the details for allowing Web Real-Time Communication (WebRTC) IMS Clients (WIC)
to access the IP Multimedia (IM) Core Network (CN) subsystem.
The present document is applicable to WebRTC IMS client (WIC), eP-CSCF, eIMS-AGW, WebRTC Web Server
Function (WWSF) and WebRTC Authorization Function (WAF).
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] IETF RFC 7118: "The WebSocket Protocol as a Transport for the Session Initiation Protocol
(SIP)".
[3] 3GPP TS 24.229: "IP multimedia call control protocol based on Session Initiation Protocol (SIP)
and Session Description Protocol (SDP); Stage 3".
[4] 3GPP TS 23.228: " IP Multimedia Subsystem (IMS); Stage 2".
[5] IETF RFC 5763: "Framework for Establishing a Secure Real-time Transport Protocol (SRTP)
Security Context Using Datagram Transport Layer Security (DTLS)".
[6] IETF RFC 5764: "Datagram Transport Layer Security (DTLS) Extension to Establish Keys for the
Secure Real-time Transport Protocol (SRTP)".
[7] 3GPP TS 22.173: "IP Multimedia Core Network Subsystem (IMS) Multimedia Telephony Service
and supplementary services; Stage 1".
[8] 3GPP TS 24.173: "IMS multimedia telephony communication service and supplementary services;
Stage 3".
[9] 3GPP TS 33.203: "Access security for IP based services".
[10] RFC 6750 (October 2012): "The OAuth 2.0 Authorization Framework: Bearer Token Usage".
[11] 3GPP TS 23.292: "IP Multimedia Subsystem (IMS) Centralized Services; Stage 2".
[12] RFC 5009 (September 2007): "Private Header (P-Header) Extension to the Session Initiation
Protocol (SIP) for Authorization of Early Media".
[13] 3GPP TS 23.334: "IMS Application Level Gateway (IMS-ALG) – IMS Access Gateway (IMS-
AGW) interface".
[14] RFC 4145 (September 2005): "TCP-Based Media Transport in the Session Description Protocol
(SDP)".
[15] RFC 8122 (March 2017): "Connection-Oriented Media Transport over the Transport Layer
Security (TLS) Protocol in the Session Description Protocol (SDP)".
[16] draft-ietf-rtcweb-data-channel-13 (January 2015): "WebRTC Data Channels".
ETSI

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3GPP TS 24.371 version 15.3.0 Release 15 8 ETSI TS 124 371 V15.3.0 (2021-01)
Editor's note: The above document cannot be formally referenced until it is published as an RFC.
[17] draft-ietf-rtcweb-data-protocol-09 (January 2015): "WebRTC Data Channel Establishment
Protocol".
Editor's note: The above document cannot be formally referenced until it is published as an RFC.
[18] draft-ietf-mmusic-sctp-sdp-25 (March 2017): "Stream Control Transmission Protocol (SCTP)-
Based Media Transport in the Session Description Protocol (SDP)".
Editor's note: The above document cannot be formally referenced until it is published as an RFC.
[19] RFC 3261 (June 2002): "SIP: Session Initiation Protocol".
[20] RFC 3264 (June 2002): "An Offer/Answer Model with the Session Description Protocol (SDP)".
[21] RFC 7675 (October 2015): "STUN Usage for Consent Freshness".
[22] RFC 5245 (April 2010): "Interactive Connectivity Establishment (ICE): A Protocol for Network
Address Translator (NAT) Traversal for Offer/Answer Protocols".
[23] RFC 8261 (November 2017): "Datagram Transport Layer Security (DTLS) Encapsulation of
SCTP Packets".
[24] RFC 6455 (December 2011): "The WebSocket Protocol".
[25] draft-ietf-mmusic-sdp-bundle-negotiation-29 (April 2016): "Negotiating Media Multiplexing
Using the Session Description Protocol (SDP)".
Editor's note: The above document cannot be formally referenced until it is published as an RFC.
[26] RFC 3581 (August 2003): "An Extension to the Session Initiation Protocol (SIP) for Symmetric
Response Routing".
[27] RFC 8898 (September 2020): "Third-Party Token-Based Authentication and Authorization for
Session Initiation Protocol (SIP)".
[28] RFC 6544 (March 2012): "TCP Candidates with Interactive Connectivity Establishment (ICE)".
[29] Void.
[30] draft-ietf-rtcweb-overview-18 (March 2017): "Overview: Real Time Protocols for Brower-based
Applications".
Editor's note: The above document cannot be formally referenced until it is published as an RFC.
[31] Void.
[32] RFC 3310 (September 2002): "Hypertext Transfer Protocol (HTTP) Digest Authentication Using
Authentication and Key Agreement (AKA)".
[33] RFC 4169 (November 2005): "Hypertext Transfer Protocol (HTTP) Digest Authentication
...