Content for TS 24.303 Word version: 18.0.0

3.1 Definitions 3.2 Abbreviations 4.1 Mobility management based on Dual-Stack Mobile IPv6 4.2 Identities 4.3 Multiple PDN connectivity
...

1 Scope p. 7

The present document specifies the signalling procedures for accessing the 3GPP Evolved Packet Core network and handling the mobility between 3GPP and non-3GPP accesses via the S2c reference point defined in TS 23.402.

The present document is applicable to the User Equipment (UE) and the network node implementing the Home Agent functionality.

In addition the present document specifies the procedures used for the DSMIPv6 Home Agent discovery, for bootstrapping the DSMIPv6 security association between the UE and the Home Agent and for managing the DSMIPv6 tunnel. The specification of these procedures is compliant to IETF RFCs.

DSMIPv6 procedures can be used independently of the underlying access technology.

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]

RFC 5555 (June 2009): "Mobile IPv6 support for Dual Stack Hosts and Routers".

[3]

TS 23.402: "Architecture Enhancements for non-3GPP accesses".

[4]

RFC 4877 (April 2007): "Mobile IPv6 Operation with IKEv2 and the Revised IPsec Architecture".

[5] Void.

[6] Void.

[7] Void.

[8] Void.

[9] Void.

[10]

RFC 5026 (October 2007): "Mobile IPv6 bootstrapping in split scenario".

[11]

RFC 4303 (December 2005): "IP Encapsulating Security Payload (ESP)".

[12]

RFC 6610 (May 2012): "DHCP Options for Home Information Discovery in Mobile IPv6 (MIPv6)".

[13]

RFC 3736 (April 2004): "Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6".

[14]

RFC 5996 (September 2010): "Internet Key Exchange Protocol Version 2 (IKEv2)".

[15]

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

[16] Void.

[17]

TS 23.003: "Numbering, addressing and identification".

[18]

TS 33.402: "3GPP System Architecture Evolution (SAE); Security aspects of non-3GPP accesses".

[19]

RFC 5846 (June 2010): "Binding Revocation for IPv6 Mobility".

[20]

TS 29.273: "3GPP EPS AAA interfaces".

[21]

TS 24.302: "Access to the Evolved Packet Core (EPC) via non-3GPP access networks; Stage 3".

[22] Void.

[23]

RFC 4739 (November 2006): "Multiple Authentication Exchanges in the Internet Key Exchange (IKEv2) Protocol".

[24]

TS 33.234: "Wireless Local Area Network (WLAN) interworking security".

[25] Void.

[26]

RFC 4039 (March 2005): "Rapid Commit Option for the Dynamic Host Configuration Protocol version 4 (DHCPv4)".

[27]

RFC 6275 (July 2011): "Mobility Support in IPv6".

[28]

RFC 4187 (January 2006): "Extensible Authentication Protocol Method for 3rd Generation Authentication and Key Agreement (EAP AKA)".

[29]

RFC 3963 (January 2005): "Network Mobility (NEMO) Basic Support Protocol".

[30]

RFC 5685 (November 2009): "Redirect Mechanism for the Internet Key Exchange Protocol Version 2 (IKEv2)".

[31]

RFC 5648 (October 2009): "Multiple Care-of Addresses Registration".

[32]

RFC 6089 (January 2011): "Flow Bindings in Mobile IPv6 and Network Mobility (NEMO) Basic Support".

[33]

RFC 6088 (January 2011): "Traffic Selectors for Flow Bindings".

[34]

TS 23.261: "IP flow mobility and seamless Wireless Local Area Network (WLAN) offload; Stage 2".

[35]

RFC 6276 (July 2011): "DHCPv6 Prefix Delegation for Network Mobility (NEMO)".

[36]

TS 24.312: "Access Network Discovery and Selection Function (ANDSF) Management Object (MO)".

3 Definitions and abbreviations p. 8

3.1 Definitions p. 8

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

The following terms used in this Technical Specification are defined in RFC 6275:

Home Address

Care-of Address

binding cache

binding cache entry

The following terms used in this Technical Specification are defined in RFC 5648, and RFC 6089:

Binding Identification Number

Flow, Flow Binding

Flow Identifier

Traffic Selector.

The following term used in this Technical Specification is defined in TS 23.402:

IFOM capable UE

The following terms used in this Technical Specification are defined in TS 23.261:

routing address

routing filter

routing rule

Home network prefix:

An IPv6 prefix allocated by the Home Agent to the UE and used by the UE to configure the Home Address. The Home network prefix is uniquely allocated to a UE.

Home Agent:

The Home Agent functionality consists in the DSMIPv6 anchor point functionality described in RFC 5555 and RFC 4877. Based on TS 23.402 the HA functionality is implemented in the PDN Gateway.

3.2 Abbreviations p. 9

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

BID

Binding Identification Number

DSMIPv6

Dual-Stack MIPv6

EPC

Evolved Packet Core

ePDG

Evolved Packet Data Gateway

EPS

Evolved Packet System

FID

Flow Identifier

Gateway

Home Agent

MIPv6

Mobile IP version 6

TSi

Traffic Selector - Initiator

TSr

Traffic Selector - Responder

User Equipment

4 General p. 9

4.1 Mobility management based on Dual-Stack Mobile IPv6 p. 9

DSMIPv6 is specified in RFC 6275 and RFC 5555. The purpose of the DSMIPv6 procedures is to establish, manage and tear down a mobility tunnel between the UE and the HA function. The mobility tunnel establishment is always initiated by the UE, while the mobility tunnel tear down can be initiated either by the UE or the network. Communication between the UE and a correspondent node shall use the bidirectional mode of operation. Route optimization mode of operation is not supported by EPC in this release.

In this specification, the RFC 4877 is used to secure DSMIPv6 signalling. For this purpose, the UE performs an IKEv2 exchange with the HA before establishing the mobility tunnel as described in subclause 5.1.2.2. The details of the security aspects are specified in TS 33.402.

The mobility tunnel procedures are performed by the UE for each PDN connection, meaning that if multiple PDNs are accessed by the UE, multiple instances of the procedures are needed. The multiple PDN connections behaviour is specified more in detail in subclause 4.3.

In this specification, the RFC 3963 is used for prefix preservation. For this purpose, the UE uses the implicit mode as stated in RFC 3963 to tell the HA that the home network prefix would be preserved during mobility. The support of this operation is limited to the sending and receiving of IPv6 packets containing IPv6 addresses auto-configured from the home network prefix, in addition to the IPv6 Home Address.

In this specification, the RFC 5648, RFC 6089 and RFC 6088 are used for IFOM. The general principles of IFOM are listed in TS 23.261. For this purpose, the UE can decide if IFOM is to be applied to a PDN connection. The procedures used by the UE to determine which PDN connection IFOM is to be applied and how the IP flows are distributed are specified in TS 24.302.

4.2 Identities p. 9

The UE shall use Network Access Identifier (NAI) as identification towards the HA in the IKEv2 exchange. During this process, the IPsec security association between the UE and the HA is tied to the user identity, set to the NAI, and to an SPI uniquely identifying this security association. The NAI is structured according to TS 23.003. The NAI can be either a root NAI, a fast re-authentication NAI or pseudonym identity as specified in TS 23.003.

The UE shall use the HA-APN to identify the desired HA in the DNS-based and DHCPv6-based HA discovery procedures. The HA-APN is constructed according to TS 23.003.

The Binding Update and Binding Acknowledgement shall not explicitly carry an NAI as the IPsec security association is tied to the user identity.

4.3 Multiple PDN connectivity p. 10

This specification supports multiple PDN connectivity. The UE can setup multiple PDN connections with a given APN or multiple APNs using multiple DSMIPv6 sessions. There is one DSMIPv6 session per each PDN connection.

The procedures described in clause 5 shall be interpreted as procedures which are executed for each PDN connection the UE established. This implies that:

For the initial attachment of a PDN connection, the UE shall perform a Home Agent address discovery (subclause 5.1.2.1), a security association establishment via IKEv2, including the EAP-AKA authentication and the IPv6 Home Network Prefix assignment (subclause 5.1.2.2), and the initial binding registration (subclause 5.1.2.4).
The handover procedure shall be performed for each PDN connection separately as described in subclause 5.2.2.
The re-registration procedure shall be performed for each PDN connection separately as described in subclause 5.3.2.
The detach procedure shall be performed for each PDN connection separately as described in subclause 5.4.2 or in subclause 5.4.3.

In addition to the above procedures, the following procedures described for an IFOM capable UE configured for IFOM shall be interpreted as procedures which are executed for each PDN connection that the UE has decided to apply the IFOM procedures. This implies that:

The attach to additional access network procedure, as described in subclause 5.6.2, shall be performed by the UE separately for each PDN connection to which the access is to be the added.
The inter-access flow mobility procedure, as described in subclause 5.7.2, shall be performed by the UE separately for each PDN connection when IP flows are to be moved amongest access networks.
The removal of an access network procedure, as described in subclause 5.8.2, shall be performed by the UE separately for each PDN connection using the access network to be removed.