5 Mobility Management procedures

29.2753GPPProxy Mobile IPv6 (PMIPv6) based Mobility and Tunnelling protocolsRelease 17Stage 3TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.1 Proxy Mobile IPv6 PDN Connection Creation procedure

5.1.1 General

The PMIPv6 PDN Connection Creation procedure is initiated by the node acting as a MAG to create a new PDN connection with the node acting as an LMA for an UE that either attaches for the first time to the EPC, or connects to an additional PDN. The procedure starts with the MAG sending a PBU including the APN to the LMA to register with the LMA a binding for the UE’s PDN connection. If multiple PDN connections to the same APN function is supported by the MAG, a PDN connection ID shall also be included in the same PBU message. The LMA confirms establishment of the binding by sending a PBA to the MAG. If multiple PDN connections to the same APN function is supported by the LMA, the received PDN connection ID shall also be included in the same PBA message. Establishment of the binding achieves the following:

– PDN selection: The LMA select the PDN based on the APN contained in the PBU.

– IPv6 Home Network Prefix assignment: The LMA assigns to the UE’s PDN connection an IPv6 Home Network Prefix valid in the selected PDN.

– IPv4 Home Address assignment: The LMA assigns to the UE’s PDN connection an IPv4 Home Address valid in the selected PDN.

– Downlink and Uplink GRE Key Assignment: The MAG and LMA will establish downlink and uplink GRE keys to be used for GRE encapsulation of the PDN connection’s downlink and uplink traffic, respectively.

– GRE Tunnel Establishment: A GRE tunnel is established between the MAG and LMA with the assigned GRE keys to carry uplink and downlink traffic that the UE respectively sends and receives on the PDN connection.

– BCE Creation: The LMA creates a BCE for the PDN connection.

– BULE Creation: The MAG creates a BULE for the PDN connection.

– MAG Link Local Address assignment: The LMA assigns the MAG link local address.

– UE Interface Identifier (IID) assignment: The LMA assigns to the UE an IPv6 Interface Identifier to allow formation of an UE Link Local Address from the well-known link local address prefix (fe80::/64).

– PDN connection ID: The PDN connection ID is provided by the MAG and accepted by LMA, if multiple PDN connections to the same APN function is supported by both MAG and LMA.

– LMA Control Plane Address: the LMA may assign an alternate LMAA or IPv4-LMAA, if this option is supported by both MAG and LMA.

– LMA User Plane Address: the LMA may assign an alternate LMA address for user plane, if this option is supported by both MAG and LMA.

Regarding the usage and support of the protocol number in the pseudo-header see Annex B.

5.1.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 PDN Connection Creation procedure are depicted in Table 5.1.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 PDN Connection Creation procedure are depicted in Table 5.1.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.1.1.1-1: Fields of a PBU message for the PMIPv6 PDN Connection Creation procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.1.1.1-2: Mobility Options in a PBU message for the PMIPv6 PDN Connection Creation procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the NAI identifier of the UE as specified in 3GPP TS 23.003 [12]. The format of the NAI is specified in the subclause 19.3 in 3GPP TS 23.003 [12].	3GPP TS 23.003 [12]
Ipv6 Home Network Prefix option	C	For dynamic allocation, set the Home Network Prefix to the value "0::0" and Prefix Length to the value "0" to request allocation for the UE’s PDN connection of an Ipv6 Home Network Prefix in the PDN corresponding the EPS Access Point Name. For static allocation, set the Home Network Prefix to the received static allocated Ipv6 Home Network Prefix and Prefix Length to the value "64". NOTE 1.	IETF RFC 5213 [4]
Link-local Address	C	Present when Ipv6 Home Network Prefix option is present. Link-local address of the MAG. Set to ALL_ZERO (all bits set to 0), indicating that the MAG requests a link-local address to be used on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "1" to indicate attachment over a new interface.	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e. GERAN, UTRAN, E-UTRAN or NB-IoT, or to the value matching the characteristics of the non-3GPP access (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile Ipv6 Parameters Registry [18]. The ePDG may use the access technology type of the untrusted non-3GPP access network if it is able to acquire it; otherwise it shall indicate Virtual as the access technology. The TWAN shall set the Access Technology Type Option value to 4 i.e. "IEEE 802.11a/b/g" on the S2a interface. NOTE 2. NOTE 3.	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
GRE key option	M	Set to the downlink GRE key to be used for downlink GRE encapsulated packets sent over the PDN connection.	IETF RFC 5845 [7]
Ipv4 Home Address Request option	C	For dynamic allocation, set the Ipv4 Home Address to the value "0.0.0.0" and Prefix-len to the value "0" or "32" to request allocation for the UE’s PDN connection of an Ipv4 Home Address in the PDN corresponding to the EPS Access Point Name. For static allocation, set the Ipv4 Home Address to the received static allocated Ipv4 Home Address and Prefix-len to the value "32". NOTE 1.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE attaches the new PDN connection. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 4.	IETF RFC 5149 [11]
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
PDN GW IP Address	O	Contain PDN GW IP address (on S2a or S2b when used for chained S2a/S2b-PMIP based S8).	Subclause 12.1.1.4
MAG Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MAG on the S5/S8, S2a (for Trusted WLAN Access) and S2b interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
MME Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MME, and included by the MAG on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
Selection Mode	O	Contains APN selection mode (on S5/S8).	Subclause 12.1.1.7
Charging Characteristics	O	Contains the Charging Characteristics to be applied for EPC charging	Subclause 12.1.1.8
Serving Network	C	This IE shall be included on S2a (for TWAN access),S5 and S8 interfaces to identify the Serving Network. This IE may be included on S2a to identify the Serving Network of the eHRPD access network.	Subclause 12.1.1.9
Mobile Equipment Identity	O	This IE shall contain the MEI of the UE and shall be present, if available, on the S5, S8, S2a or S2b interface.	Subclause 12.1.1.10
MSISDN	O	This IE shall contains the MSISDN and shall be present, if available, on the S5, S8, S2a or S2b interfaces.	Subclause 12.1.1.11
Maximum APN Restriction	O	Contains the most stringent restriction of already active PDN connections (on S5/S8).	Subclause 12.1.1.13
Unauthenticated IMSI	O	Contains the Unauthenticated IMSI	Subclause 12.1.1.14
PDN connection ID	O	Contains the PDN connection ID	Subclause 12.1.1.15
Signalling Priority Indication	O	The SGW shall forward this IE on the S5/S8 interfaces if received from the MME/SGSN.	Subclause 12.1.1.17
Additional Protocol Configuration Options	O	Contains Additional Protocol Configuration Options.	Subclause 12.1.1.19
MME/SGSN Identifier	O	The SGW shall include the MME/SGSN Identifier on the S5 interface if the SGW supports the PGW triggered SGW restoration procedure and this information is received from the MME/SGSN as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.20
Access Network Identifier Option	O	The TWAN shall include the access network identifier on S2a.	IETF RFC 6757 [37] IETF RFC 7563 [41]
Trusted WLAN Mode Indication	O	Contains the selected trusted WLAN mode (SCM or MCM) on S2a interface.	Subclause 12.1.1.22
UE Time Zone	O	The TWAN shall include the UE Timezone on the S2a interface.	Subclause 12.1.1.23
Logical Access ID	O	Contains the Circuit-ID with the Relay Identity that allocated it.	Subclause 12.1.1.25
Redirect-Capability Mobility Option	O	The MAG shall include this IE on the S5, S8, S2a and S2b interface if it supports the capability to receive from the LMA an alternate LMAA or Ipv4-LMAA.	IETF RFC 6463 [43]
LMA User-Plane Address Mobility Option	O	The MAG shall include this IE on the S5, S8, S2a and S2b interface if it supports the capability to receive from the LMA an alternate LMA address for user plane. If so, the LMA User-Plane Address field within this Mobility Option shall be a zero-length field, or have a value of ALL_ZERO with all bits in the Ipv4 address or the Ipv6 address set to zero.	IETF RFC 7389 [44]
Origination Time Stamp	O	The SGW shall forward this IE on the S5/S8 interface if received from the MME/SGSN and if it supports the procedure specified in subclause 13.2 of 3GPP TS 29.274 [22]. The TWAN/ePDG shall include this IE on the S2a/S2b interface for the conditions specified in subclause 13.2 of 3GPP TS 29.274 [22].	Subclause 12.1.1.26
Maximum Wait Time	O	The SGW shall forward this IE on the S5/S8 interface if received from the MME/SGSN and if it supports the procedure specified in subclause 13.3 of 3GPP TS 29.274 [22]. The TWAN/ePDG shall include this IE on the S2a/S2b interface for the conditions specified in subclause 13.3 of 3GPP TS 29.274 [22].	Subclause 12.1.1.27
TWAN capabilities	O	The MAG shall include this IE on the S2a interface if any of the applicable flags is set to 1. Applicable flags are: – WLCP PDN Connection Modification Support Indication: This flag shall be set to 1 on the S2a interface if the TWAN supports the WLCP PDN Connection Modification procedure.	Subclause 12.1.1.28
NOTE 1: At least one of the two options, namely, the IPv6 Home Network Prefix option or the IPv4 Home Address Request option shall be present. If both an IPv6 Home Network Prefix and an IPv4 Home Address are requested, both options shall be included in the same PBU message. NOTE 2: The methods that the ePDG may use to acquire the access technology type of the untrusted non-3GPP IP access network are not specified in this release. NOTE 3: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types. NOTE 4: The APN field is not encoded as a dotted string as commonly used in documentation.

5.1.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 PDN Connection Creation procedure are depicted in Table 5.1.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 PDN Connection Creation procedure are depicted in Table 5.1.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.1.1.2-1: Fields of a PBA message for the PMIPv6 PDN Connection Creation procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to the granted number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.1.1.2-2: Mobility Options in a PBA message for the PMIPv6 PDN Connection Creation procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	C	Present if IPv6 Home Network Prefix is allocated. When it’s present, set the Home Network Prefix to the IPv6 Home Network Prefix Allocated for the UE’s PDN connection based on the selected PDN corresponding to the EPS Access Point Name for dynamic allocation, or set to the static IPv6 Home Network Prefix received in the PBU for static allocation. The Prefix Length is set to the value "64". In addition, the Interface Identifier (IID) allocated for the UE is encoded in the low order 64 bits of this option, i.e., the IPv6 Home Network Prefix option.	IETF RFC 5213 [4]
Link-local Address	C	Present when IPv6 Home Network Prefix option is present. Link-local address to be used by the MAG on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
GRE key option	M	Set to the uplink GRE key to be used for uplink GRE encapsulated packets sent over the PDN connection.	IETF RFC 5845 [7]
IPv4 Home Address Reply Option	C	Present if IPv4 address is allocated. When it’s present, set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN corresponding to the EPS Access Point Name for dynamic allocation, or set to the static IPv4 Home Address received in the PBU for static allocation. The Prefix-len is set to a non-zero value. NOTE 1	IETF RFC 5844 [5]
IPv4 Default Router Address Option	C	his option shall be present if and only if IPv4 Home Address Reply Option is present and for trusted WLAN access if the transparent Single-connection mode is used. The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message, formatted as defined in 3GPP TS 23.003 [12] The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 2.	IETF RFC 5149[11]
PDN Type Indication	C	This option shall be present if and only if PDN type is changed in the PDN GW compared to what was requested in the PBU.	Subclause 12.1.1.3
DHCPv4 Address Allocation Procedure Indication	C	This option shall be present if and only if DHCPv4 is to be used to allocate the IPv4 address to the UE.	Subclause 12.1.1.5
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8/S2a)	Subclause 12.1.1.1
LMA Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the LMA on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
Charging ID	M	Contain the Charging ID information	Subclause 12.1.1.6
APN Restriction	O	Contains the restriction of this PDN connection (on S5/S8).	Subclause 12.1.1.12
PDN connection ID	O	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
PGW Back-Off Time	O	This IE may be included on the S5/S8/S2a interfaces when the PDN GW rejects the Proxy Binding Update with the 3GSPEC set to "APN congestion".	Subclause 12.1.1.16
Additional Protocol Configuration Options	O	Contains Additional Protocol Configuration Options.	Subclause 12.1.1.19
Access Network Identifier Option	O	Contains the access network identifier option received in PBU with the sub-options accepted (on S2a when TWAN access is used)	IETF RFC 6757 [37] IETF RFC 7563 [41]
Redirect Mobility Option	O	The LMA may include this IE on the S5, S8, S2a and S2b interface if the LMA supports sending an alternate LMAA or IPv4-LMAA and the MAG indicated corresponding support in the PBU message. If so, the LMA shall include one instance of this IE and set it to the alternate LMAA or IPv4-LMAA (for an IPv6 or IPv4 transport network respectively). (see NOTE 3)	IETF RFC 6463 [43]
LMA User-Plane Address Mobility Option	O	The LMA may include this IE on the S5, S8, S2a and S2b interface if the LMA supports sending an alternate LMA address for user plane and the MAG indicated corresponding support in the PBU message. If so, the LMA shall include only one instance of this IE and set it to the IPv4 or IPv6 address for user plane (for an IPv4 or IPv6 transport network respectively).	IETF RFC 7389 [44]
NOTE 1: If the PDN type is IPv4v6 and DHCPv4 is to be used to allocate the IPv4 address to the UE, the IPv4 Home Address Reply Option shall not be included. NOTE 2: The APN field is not encoded as a dotted string as commonly used in documentation. NOTE 3: As specified in IETF RFC 6463 [43], a binding for the UE’s PDN connection is created at the LMA (with the alternate LMAA or IPv4-LMAA) and thus the MAG does not need to send a new PBU to that LMA for creating such a binding.

5.1.2 MAG procedures

A MAG initiating the PMIPv6 PDN Connection Creation procedure shall follow the "Mobile Node Attachment and Initial Binding Registration" procedure described in the PMIPv6 IETF RFC 5213 [4] taking into account the corrections regarding the protocol number definition in IETF RFC6275 [8] and interworking solution specified in Annex B and IPv4 support for PMIPv6 IETF RFC 5844 [5] specifications with the following additional requirements:

1. Generate a downlink GRE key that is not already in use locally for the PDN connection’s downlink traffic to that UE, as specified in the GRE Key Option for PMIPv6 specification IETF RFC 5845 [7].

2. For IP address allocation, the IPv6 Home Network Prefix option and/or the IPv4 Home Address Request option shall be present according to the UE request and the user subscription for non-3GPP access, or according to the PDN Type received from the MME/SGSN for 3GPP access.

3. If the static IPv4 Home Address and/or IPv6 Home Network Prefix are available at the MAG, set them in the IPv4 home address Request option and/or the IPv6 home prefix option in the PBU.

4. Optionally, assign a Fully Qualified PDN Connection Set Identifier that identifies a set of PDN connections belonging to an arbitrary number of UEs.

5. Provide a PDN connection ID, if multiple PDN connections to the same APN function is supported by the MAG.

6. Include the Redirect-Capability Mobility Option if the MAG supports the capability to receive from the LMA an alternate LMAA or IPv4-LMAA.

7. Include the LMA User Plane Address Mobility Option if the MAG supports the capability to receive from the LMA an alternate LMA address for user plane.

8. Set other parameters in the PBU as specified by the PBU parameters section for this procedure.

5.1.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Initial Binding Registration (New Mobility session)" and "Processing Binding Registrations" procedures described in the PMIPv6 IETF RFC 5213 [4] taking into account the corrections regarding the protocol number definition in IETF RFC6275 [8] and interworking solution specified in Annex B and IPv4 support for PMIPv6 IETF RFC 5844 [5] specifications with the following additional requirements:

1. Select the PDN for the UE’s PDN connection based on the APN present in the PBU.

2. Check if the received IPv6 Home prefix and/or IPv4 Home address are topologically correct.

3. If no static IPv6 Home Network Prefix and/or IPv4 Home Address were received in the PBU, allocate the IPv6 Home Network Prefix and/or an IPv4 Home Address for the selected PDN.

4. If a PCO with value IPv4 Address Allocation via DHCPv4 is present in the PBU,

– if the LMA allocates an IPv4 address, it shall include the IPv4 Home Address Reply Option in the PBA message

– if the LMA allocates an IPv6 prefix, the LMA shall not allocate an IPv4 address and shall not include the IPv4 Home Address Reply Option in the PBA message

5. Generate a uplink GRE key that is not already in use locally for the PDN connection’s uplink traffic from that UE, as specified in the GRE Key Option for PMIPv6 specification IETF RFC 5845 [7].

6. Assign to the UE an IPv6 Interface Identifier to allow formation of an UE Link Local Address from the well-known link local address prefix (fe80::/64).

7. Optionally, assign a Fully Qualified PDN Connection Set Identifier that identifies a set of PDN connections belonging to an arbitrary number of UEs.

8. If PDN connection ID was recevied in the PBU message,

– the LMA includes the recevied a PDN connection ID in the PBA message, if the multiple PDN connections to the same APN function is supported by the LMA; or

– the LMA ignores the received PDN connection ID and does not include it in the PBA message , if the multiple PDN connections to the same APN function is not supported by the LMA.

9. If the Redirect-Capability Mobility Option was received in the PBU message, optionally assign an alternate LMAA or IPv4-LMAA.

10. If the LMA User Plane Address Mobility Option was received in the PBU message, optionally assign an alternate LMA address for user plane.

11. Set parameters in the PBA as specified by the PBA parameters section for this procedure.

5.2 Proxy Mobile IPv6 PDN Connection Lifetime Extension procedure

5.2.1 General

The PMIPv6 PDN Connection Lifetime Extension procedure is initiated by the node acting as a MAG to prolong the lifetime of an existing PDN connection with the node acting as an LMA for an UE that is already attached. This procedure may also be used when the MME is relocated and the MAG remains unchanged (see 3GPP TS 23.007 [13]). The procedure starts with the MAG sending a PBU to the LMA to extend the binding lifetime for the UE’s PDN connection. The LMA confirms that the binding lifetime is extended by sending a PBA to the MAG.

5.2.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 PDN Connection Lifetime Extension procedure are depicted in Table 5.2.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 PDN Connection Lifetime Extension procedure are depicted in Table 5.2.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.2.1.1-1: Fields of a PBU message for the PMIPv6 PDN Connection Lifetime Extension procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.2.1.1-2: Mobility Options in a PBU message for the PMIPv6 PDN Connection Lifetime Extension procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003 [12].	IETF RFC 5213 [4], 3GPP TS 23.003 [12]
IPv6 Home Network Prefix option	C	Set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN and Prefix Length to the value "64". NOTE 1.	IETF RFC 5213 [4]
Link-local Address	C	Present when IPv6 Home Network Prefix option is present. Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "5" to indicate handoff state not changed (Re-registration).	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e. GERAN, UTRAN, E-UTRAN or NB-IoT, or to the value matching the characteristics of the non-3GPP access (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile IPv6 Parameters Registry [18]. The ePDG may use the access technology type of the untrusted non-3GPP access network if it is able to acquire it; otherwise it shall indicate Virtual as the access technology. The TWAN shall set the Access Technology Type Option value to 4 i.e. "IEEE 802.11a/b/g" on the S2a interface. NOTE 2 NOTE 3	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
GRE Key option	M	Set to the previously exchanged downlink GRE key to be used for downlink GRE encapsulated packets sent over the PDN connection.	IETF RFC 5845 [7]
IPv4 Home Address Request option	C	Set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN and Prefix-len to the non-zero value received from LMA. NOTE 1.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 4.	IETF RFC 5149[11]
MME Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MME, and included by the MAG on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
MAG Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MAG on the S5/S8, S2a (for Trusted WLAN Access) and S2b interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
PDN connection ID	C	Contains the PDN connection ID if the BULE contains the PDN Connection ID.	Subclause 12.1.1.15
NOTE 1: At least one of the two options, namely, the IPv6 Home Network Prefix option or the IPv4 Home Address Request option shall be present. If the UE has both IPv4 home address and IPv6 home network prefix registered, both the IPv6 Home Network Prefix option and IPv4 Home Address Request option shall be included in the same PBU message. NOTE 2: The methods that the ePDG may use to acquire the access technology type of the untrusted non-3GPP IP access network are not specified in this release. NOTE 3: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types. NOTE 4: The APN field is not encoded as a dotted string as commonly used in documentation.

5.2.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 PDN Connection Lifetime Extension procedure are depicted in Table 5.2.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 PDN Connection Lifetime Extension procedure are depicted in Table 5.2.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.2.1.2-1: Fields of a PBA message for the PMIPv6 PDN Connection Lifetime Extension procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to the granted number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.2.1.2-2: Mobility Options in a PBA message for the PMIPv6 PDN Connection Lifetime Extension procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	C	If it is present in the corresponding PBU, set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN and Prefix Length to the value "64".	IETF RFC 5213 [4]
Link-local Address	C	Present when IPv6 Home Network Prefix option is present. Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
GRE key option	M	Set to the previously exchanged uplink GRE key to be used for uplink GRE encapsulated packets sent over the PDN connection.	IETF RFC 5845 [7]
IPv4 Home Address Reply Option	C	If it is present in the corresponding PBU, set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN and Prefix-len to the non-zero value present in the corresponding PBU.	IETF RFC 5844 [5]
IPv4 Default Router Address Option	C	This option shall be present if and only if IPv4 Home Address Reply Option is present and PBU is accepted. The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1
LMA Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the LMA on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
PDN connection ID	C	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.2.2 MAG procedures

A MAG initiating the PMIPv6 PDN Connection Lifetime Extension procedure shall follow the "Extending Binding Lifetime" procedure described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications, while parameters in the PBU are set as specified by the PBU parameters section for this procedure. When an MME FQ-CSID is received by the MAG during MME relocation, if the MAG supports the feature according to 3GPP TS 23.007 [13], it shall store the Node ID and CSID from the MME FQ-CSID for the PDN connection and forward the MME FQ-CSID to the LMA in the PBU.

5.2.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Binding Lifetime Extension without Handover" procedure as described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications, while parameters in the PBA are set as specified by the PBA parameters section for this procedure. When an MME FQ-CSID is received by the LMA, if the LMA supports the feature according to 3GPP TS 23.007 [13], it shall store the Node-ID and CSID from the MME FQ-CSID in place of those previously stored for the PDN connection.

5.3 Proxy Mobile IPv6 PDN Connection Handover procedure

5.3.1 General

The PMIPv6 PDN Connection Handover procedure is initiated by the node acting as a new MAG for the UE to update an existing PDN connection for an UE that is already attached to the EPC. The procedure starts with the new MAG sending a PBU including the APN to the LMA to update the binding for the UE’s PDN connection. If multiple PDN connections to the same APN function is supported by the new MAG, a PDN connection ID shall also be included in the same PBU message. The LMA confirms update of the binding by sending a PBA to the MAG. If multiple PDN connections to the same APN function is supported by the LMA, the received PDN connection ID shall also be included in the same PBA message. Update of the binding achieves the following:

– IPv6 Home Network Prefix re-assignment: The LMA re-assigns to the UE’s PDN connection the IPv6 Home Network Prefix valid in the selected PDN.

– IPv4 Home Address re-assignment: The LMA re-assigns to the UE’s PDN connection the IPv4 Home Address valid in the selected PDN.

– Downlink and Uplink GRE Key Assignment: The MAG and LMA will establish downlink and uplink GRE keys to be used for GRE encapsulation of downlink and uplink traffic, respectively on the PDN connection.

– GRE Tunnel Establishment: A GRE tunnel is established between the MAG and LMA with the assigned GRE keys to carry uplink and downlink traffic that UE respectively sends and receives on the PDN connection.

– BCE Update: The LMA updates or creates the BCE for the PDN connection.

– BULE Creation: The new MAG creates a BULE for the PDN connection.

– IP address(es) preservation: the IP addresses allocated in the previous initial attachment are reused if IP address(es) preservation decision is made.

– MAG Link Local Address re-assignment: The LMA re-assigns the same MAG link local address.

– UE Interface Identifier (IID) re-assignment: The LMA re-assigns to the UE the same IPv6 Interface Identifier to allow formation of the same UE Link Local Address from the well-known link local address prefix (fe80::/64).

– PDN connection ID: The PDN connection ID is provided by the MAG and accepted by LMA, if multiple PDN connections to the same APN function is supported by both MAG and LMA.

– LMA Control Plane Address: for handover between non-3GPP and 3GPP access, the LMA may assign a possibly different alternate LMAA or IPv4-LMAA if this option is supported by both MAG and LMA. For an intra-3GPP access handover, the LMA shall re-assign the same alternate LMAA or IPv4-LMAA if such an address was allocated during the PDN connection establishment or during a handover between non-3GPP and 3GPP access.

– LMA User Plane Address: for handover between non-3GPP and 3GPP access, the LMA may assign a possibly different alternate LMA address for user plane, if this option is supported by both MAG and LMA. For an intra-3GPP access handover, the LMA shall re-assign the same alternate LMA address for user plane if such an address was allocated during the PDN connection establishment or during a handover between non-3GPP and 3GPP access.

The PMIPv6 LMA Initiated Update Notification procedure is then initiated by the LMA to notify the old MAG for handover with SGW relocation as specified in 3GPP TS 23.402 [3], to trigger the generation of End Marker by the MAG as specified in subclause 5.11.

5.3.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 PDN Connection Handover procedure are depicted in Table 5.3.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 PDN Connection Handover procedure are depicted in Table 5.3.1.1-2. When the mobility option is present in the message, only the first instance shall be recognized. If multiple instances are included in the message, the receiver ignores all other instances.

Table 5.3.1.1-1: Fields of a PBU message for the PDN Connection Handover procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.3.1.1-2: Mobility Options in a PBU message for the PMIPv6 PDN Connection Handover procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003 [12].	IETF RFC 5213 [4], 3GPP TS 23.003 [12]
IPv6 Home Network Prefix option	C	If available at the MAG, set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection and Prefix Length to the value "64". Otherwise, set the Home Network Prefix to the value "0::0" and Prefix Length to the value "0" to request allocation for the UE’s PDN connection of an IPv6 Home Network Prefix for the UE in the PDN corresponding to the EPS Access Point Name. NOTE 1.	IETF RFC 5213 [4]
Link-local Address	C	Present when IPv6 Home Network Prefix option is present. If available, set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE. If not available, set to ALL_ZERO (all bits set to 0), indicating that the MAG requests a link-local address.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "2" (Handoff between two different interfaces) in case the handover is an inter access handover (i.e. from 3GPP to non-3GPP, from non-3GPP to 3GPP, or between two non-3GPP accesses) and IP address(es) preservation decision is taken; or Set to the value "3" (Handoff between mobile access gateways for the same interface) in case the handover is an intra access (i.e. between two 3GPP accesses) handover; or Set to the value "4" (Handoff state unknown) in case the handover is an inter access handover (i.e. from 3GPP to non-3GPP, from non-3GPP to 3GPP, or between two non-3GPP accesses) and IP address(es) preservation decision is negative or unknown.	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e., to GERAN, UTRAN or E-UTRAN, or to the value matching the characteristics of the non-3GPP access (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile IPv6 Parameters Registry [18]. The ePDG may use the access technology type of the untrusted non-3GPP access network if it is able to acquire it; otherwise it shall indicate Virtual as the access technology. The TWAN shall set the Access Technology Type Option value to 4 i.e. "IEEE 802.11a/b/g" on the S2a interface. NOTE 2 NOTE 3	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
GRE key option	M	Set to the downlink GRE key to be used for downlink GRE encapsulated packets sent over the PDN connection.	IETF RFC 5845 [7]
IPv4 Home Address Request option	C	If available at the MAG, set the IPv4 Home Address to the IPv4 Address allocated to the UE’s PDN connection and Prefix-len to the value "32". Otherwise, set the IPv4 Home Address to the value "0.0.0.0" and Prefix-len to the value "0" or "32" to request allocation for the UE’s PDN connection of an IPv4 Home Address in the PDN corresponding to the EPS Access Point Name. NOTE 1.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 4.	IETF RFC 5149[11]
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
PDN GW IP Address	O	Contain PDN GW IP address (on S2a or S2b when used for chained S2a/S2b-PMIP based S8)..	Subclause 12.1.1.4
MAG Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MAG on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
MME Fully Qualified PDN Connection Set Identifier	O	Contain a Fully Qualified PDN Connection Set Identifier if generated by the MME, and included by the MAG on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
Selection Mode	C	Contains APN selection mode (on S5/S8). Shall be present if the PDN connection is initiated by S4 SGSN or MME.	Subclause 12.1.1.7
Charging Characteristics	O	Contains the Charging Characteristics to be applied for EPC charging	Subclause 12.1.1.8
Serving Network	C	This IE shall be included on S2a (for TWAN access),S5 and S8 interfaces to identify the Serving Network. This IE may be included on S2a to identify the Serving Network of the eHRPD access network.	Subclause 12.1.1.9
Mobile Equipment Identity	O	This IE shall contain the MEI of the UE and shall be present, if available, on the S5, S8, S2a or S2b interface.	Subclause 12.1.1.10
MSISDN	O	This IE shall contains the MSISDN and shall be present, if available, on the S5, S8, S2a or S2b interfaces.	Subclause 12.1.1.11
Maximum APN Restriction	O	Contains the most stringent restriction of already active PDN connections (on S5/S8).	Subclause 12.1.1.13
PDN connection ID	O	Contains the PDN connection ID	Subclause 12.1.1.15
Signalling Priority Indication	O	The SGW shall forward this IE on the S5/S8 interfaces during the handover from non-3GPP to 3GPP procedure.	Subclause 12.1.1.17
MME/SGSN Identifier	O	The SGW shall include the MME/SGSN Identifier on the S5 interface if the SGW supports the PGW triggered SGW restoration procedure and this information is received from the MME/SGSN as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.20
Access Network Identifier Option	O	The TWAN shall include the access network identifier on S2a.	IETF RFC 6757 [37] IETF RFC 7563 [41]
Trusted WLAN Mode Indication	O	Contains the selected trusted WLAN mode (SCM or MCM) on S2a interface.	Subclause 12.1.1.22
UE Time Zone	O	The TWAN shall include the UE Timezone on the S2a interface.	Subclause 12.1.1.23
Logical Access ID	O	Contains the Circuit-ID with the Relay Identity that allocated it.	Subclause 12.1.1.25
Redirect-Capability Mobility Option	O	The MAG shall include this IE on the S5, S8, S2a and S2b interface if it supports the capability to receive from the LMA an alternate LMAA or IPv4-LMAA.	IETF RFC 6463 [43]
LMA User-Plane Address Mobility Option	O	The MAG shall include this IE on the S5, S8, S2a and S2b interface if it supports the capability to receive from the LMA an alternate LMA address for user plane. If so, the LMA User Plane Address field within this Mobility Option shall be a zero-length field, or have a value of ALL_ZERO with all bits in the IPv4 address or the IPv6 address set to zero.	IETF RFC 7389 [44]
TWAN capabilities	O	The MAG shall include this IE on the S2a interface if any of the applicable flags is set to 1. Applicable flags are: – WLCP PDN Connection Modification Support Indication: This flag shall be set to 1 on the S2a interface if the TWAN supports the WLCP PDN Connection Modification procedure.	Subclause 12.1.1.28
NOTE 1: At least one of the two options, namely, the IPv6 Home Network Prefix option or the IPv4 Home Address Request option shall be present. If the MAG knows the UE has both IPv4 home address and IPv6 home network prefix registered, both the IPv6 Home Network Prefix option and IPv4 Home Address Request option shall be included in the same PBU message. NOTE 2: The methods that the ePDG may use to acquire the access technology type of the untrusted non-3GPP IP access network are not specified in this release. NOTE 3: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types. NOTE 4: The APN field is not encoded as a dotted string as commonly used in documentation.

5.3.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 PDN Connection Handover procedure are depicted in Table 5.3.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 PDN Connection Handover procedure are depicted in Table 5.3.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.3.1.2-1: Fields of a PBA message for the PMIPv6 PDN Connection Handover procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to the granted number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.3.1.2-2: Mobility Options in a PBA message for the PMIPv6 PDN Connection Handover procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	C	Present if IPv6 Home Network Prefix is allocated. When it’s present, set the Home Network Prefix to the IPv6 Home Network Prefix Allocated for the UE’s PDN connection based on the selected PDN corresponding to the EPS Access Point Name for dynamic allocation, or set to the static IPv6 Home Network Prefix received in the PBU for static allocation. The Prefix Length is set to the value "64". In addition, the Interface Identifier (IID) allocated for the UE is encoded in the low order 64 bits of this option, i.e., the IPv6 Home Network Prefix option.	IETF RFC 5213 [4]
Link-local Address	C	Present when IPv6 Home Network Prefix option is present. Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
GRE key option	M	Set to the uplink GRE key to be used for uplink GRE encapsulated packets sent over the PDN connection. The same uplink GRE key used for the UE’s PDN connection with the previous MAG shall be re-assigned.	IETF RFC 5845 [7]
IPv4 Home Address Reply Option	C	Present if IPv4 address is allocated. When it’s present, set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN corresponding to the EPS Access Point Name for dynamic allocation, or set to the static IPv4 Home Address received in the PBU for static allocation. The Prefix-len is set to a non-zero value.	IETF RFC 5844 [5]
IPv4 Default Router Address Option	C	This option shall be present if and only if IPv4 Home Address Reply Option is present and for trusted WLAN access if the transparent Single-connection mode is used. The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149 [11]
PDN Type Indication	C	This option shall be present if and only if PDN type is changed in the PDN GW compared to what was requested in the PBU.	Subclause 12.1.1.3
PMIPv6 DHCPv4 Address Allocation Procedure Indication	C	This option shall be present if and only if DHCPv4 is to be used to allocate the IPv4 address to the UE.	Subclause 12.1.1.5
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1
LMA Fully Qualified PDN Connection Set Identifier List	O	Contain a Fully Qualified PDN Connection Set Identifiers if generated by the LMA on the S5/S8 interfaces as specified in 3GPP TS 23.007 [13].	Subclause 12.1.1.2
Charging ID	M	Contain the Charging ID information	Subclause 12.1.1.6
APN Restriction	O	Contains the restriction of this PDN connection (on S5/S8).	Subclause 12.1.1.12
PDN connection ID	O	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
Static IP Address Allocation Indication	O	Contains Static IP Address Allocation Indication if the IPv4 address and/or IPv6 Home Network Prefix is statically allocated. See NOTE 2	Subclause 12.1.1.18
Access Network Identifier Option	O	Contains the access network identifier option received in PBU with the sub-options accepted (on S2a when TWAN access is used)	IETF RFC 6757 [37] IETF RFC 7563 [41]
Redirect Mobility Option	O	The LMA may include this IE on the S5, S8, S2a and S2b interface if the LMA supports sending an alternate LMAA or IPv4-LMAA and the MAG indicated corresponding support in the PBU message. If so, the LMA shall include one instance of this IE and set it to the alternate LMAA or IPv4-LMAA (for an IPv6 or IPv4 transport network respectively). (see NOTE 3)	IETF RFC 6463 [43]
LMA User-Plane Address Mobility Option	O	The LMA may include this IE on the S5, S8, S2a and S2b interface if the LMA supports sending an alternate LMA address for user plane and the MAG indicated corresponding support in the PBU message. If so, the LMA shall include only one instance of this IE and set it to the IPv4 or IPv6 address for user plane (for an IPv4 or IPv6 transport network respectively).	IETF RFC 7389 [44]
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation. NOTE 2: Static IP Address Allocation Indication is used by MAG to provide dynamic IPv4/v6 address flag information as specified in 3GPP TS 32.251 [25]. NOTE 3: As specified in IETF RFC 6463 [43], a binding for the UE’s PDN connection is created at the LMA (with the alternate LMAA or IPv4-LMAA) and thus the MAG does not need to send a new PBU to that LMA for creating such a binding.

5.3.2 MAG procedures

A MAG initiating the PMIPv6 PDN Connection Handover procedure shall follow the "Mobile Node Attachment and Initial Binding Registration" procedure described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications with the following additional requirements:

1. Generate a downlink GRE key that is not already in use locally for the PDN connection’s downlink traffic to that UE, as specified in the GRE Key Option for PMIPv6 specification [7].

2. Provide a PDN connection ID, if multiple PDN connections to the same APN function is supported by the MAG.

3. Set other parameters in the PBU as specified by the PBU parameters section for this procedure.

4. Optionally, assign a Fully Qualified PDN Connection Set Identifier that identifies a set of PDN connections belonging to an arbitrary number of UEs.

5. Include the Redirect-Capability Mobility Option if the MAG supports the capability to receive from the LMA an alternate LMAA or IPv4-LMAA.

6. Include the LMA User Plane Address Mobility Option if the MAG supports the capability to receive from the LMA an alternate LMA address for user plane.

5.3.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Binding Lifetime Extension (After handoff)" and "Processing Proxy Binding Updates" procedures described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications with the following additional requirements:

1. Re-assign the same uplink GRE key that was used by the previous MAG for the PDN connection’s uplink traffic from the UE, as specified in the GRE Key Option for PMIPv6 specification [7].

2. Check if the received IPv6 Home prefix and/or IPv4 Home address are topologically correct.

3. Dynamic IP address allocation:

a) If Handoff Indicator option is "2" or "3": Re-allocate the IPv6 Home Network Prefix and/or the IPv4 Home Address for the selected PDN which were/was allocated during the previous attachment.

b) If Handoff Indicator option is "4": Make the IP address preservation decision as per the PMIPv6 specification [4].

3a. Static IP address allocation: If the IPv4 address and/or IPv6 Home Network Prefix is statically allocated, the LMA includes Static IP Address Allocation Indication in the PBA message.

4. Optionally, assign or reuse a Fully Qualified PDN Connection Set Identifier that identifies a set of PDN connections belonging to an arbitrary number of UEs.

5. If PDN connection ID was received in the PBU message,

a) the LMA updates PDN connection ID in the BCE accordingly and includes the received a PDN connection ID in the PBA message, if the multiple PDN connections to the same APN function is supported by the LMA; or

b) the LMA ignores the received PDN connection ID and does not include the received a PDN connection ID in the PBA message, if the multiple PDN to the same APN function is not supported by the LMA.

6. If the Redirect-Capability Mobility Option was received in the PBU message,

– for handover between non-3GPP and 3GPP access, the LMA may assign a possibly different alternate LMAA or IPv4-LMAA;

– for an intra-3GPP access handover, the LMA shall re-assign the same alternate LMAA or IPv4-LMAA if such an address was allocated during the PDN connection establishment or during a handover between non-3GPP and 3GPP access.

7. If the LMA User Plane Address Mobility Option was received in the PBU message,

– for handover between non-3GPP and 3GPP access, the LMA may assign a possibly different alternate LMA address for user plane;

– for an intra-3GPP access handover, the LMA shall re-assign the same alternate LMA address for user plane if such an address was allocated during the PDN connection establishment or during a handover between non-3GPP and 3GPP access.

8. Set parameters in the PBA as specified by the PBA parameters section for this procedure.

The LMA performs the lookup of BCE as described in subclause 5.8.3. If no existing BCE is found, the LMA shall follow the Proxy Mobile IPv6 PDN Connection Creation procedure as specified in section 5.1.3.

5.4 Proxy Mobile IPv6 MAG Initiated PDN Connection Deletion procedure

5.4.1 General

The PMIPv6 MAG Initiated PDN Connection Deletion procedure is initiated by the node acting as a MAG to tear down an existing PDN connection with the node acting as an LMA. The procedure starts with the MAG sending a PBU to the LMA to deregister with the LMA a binding for the UE’s PDN connection. The LMA confirms deregistration of the binding by sending a PBA to the MAG. Deregistration of the binding achieves the following:

– IPv6 Home Network Prefix deallocation: When the PDN connection is released, the LMA returns the IPv6 Home Network Prefix assigned to the UE’s PDN connection to the pool of free IPv6 Home Network Prefixes.

– IPv4 Home Address deallocation: When the PDN connection is released, the LMA returns the IPv4 Home Address assigned to the UE’s PDN connection to the pool of free IPv4 Home Network Addresses.

– Downlink and Uplink GRE Key de-assignment: The MAG and LMA will return, respectively, the PDN connection’s uplink and downlink GRE keys to their respective pool of free GRE keys.

– GRE Tunnel Tear-down: The GRE tunnel between the MAG and LMA is deleted.

– BCE Deletion: The LMA deletes the BCE for the PDN connection.

– BULE Deletion: The MAG deletes the BULE for the PDN connection.

5.4.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure are depicted in Table 5.4.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure are depicted in Table 5.4.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.4.1.1-1: Fields of a PBU message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to "0" to request deletion of the BCE.	IETF RFC 6275 [8]

Table 5.4.1.1-2: Mobility Options in a PBU message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003 [12].	IETF RFC 5213 [4], 3GPP TS 23.003 [12]
IPv6 Home Network Prefix option	C	Set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN and Prefix Length to the value "64". NOTE 1.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "4" to indicate Handoff state unknown.	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e., to GERAN, UTRAN,E-UTRAN or NB-IoT, or to the value matching the characteristics of the non-3GPP access (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile IPv6 Parameters Registry [18]. The ePDG may use the access technology type of the untrusted non-3GPP access network if it is able to acquire it; otherwise it shall indicate Virtual as the access technology. The TWAN shall set the Access Technology Type Option value to 4 i.e. "IEEE 802.11a/b/g" on the S2a interface. NOTE 2 NOTE 3	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
IPv4 Home Request Address option	C	Set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN and Prefix-len to the non-zero value received from the LMA. NOTE 1.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 4.	IETF RFC 5149[11]
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
PDN connection ID	C	Contains the PDN connection ID if the BULE contains the PDN Connection ID.	Subclause 12.1.1.15
Access Network Identifier Option	O	The TWAN shall include the access network identifier on S2a.	IETF RFC 6757 [37] IETF RFC 7563 [41]
UE Time Zone	O	The TWAN shall include the UE Timezone on the S2a interface.	Subclause 12.1.1.23
Access Network Identifier Timestamp	O	The TWAN shall include the timestamp on the S2a interface if the Access Network Identifier option is present. It shall indicate the time when the TWAN acquired the Access Network Identifier.	Subclause 12.1.1.24
NOTE 1: At least one of the two options, namely, the IPv6 Home Network Prefix option or the IPv4 Home Address Request option shall be present. If the UE has both IPv4 home address and IPv6 home network prefix registered, both the IPv6 Home Network Prefix option and IPv4 Home Address Request option shall be included in the same PBU message. NOTE 2: The methods that the ePDG may use to acquire the access technology type of the untrusted non-3GPP IP access network are not specified in this release. NOTE 3: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types. NOTE 4: The APN field is not encoded as a dotted string as commonly used in documentation.

5.4.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure are depicted in Table 5.4.1.2-1.

The Mobility Options in a PBA message for the MAG Initiated PDN Connection Deletion procedure are depicted in Table 5.4.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.4.1.2-1: Fields of a PBA message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to a value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to "0" to request deletion of the binding.	IETF RFC 6275 [8]

Table 5.4.1.2-2: Mobility Options in a PBA message for the PMIPv6 MAG Initiated PDN Connection Deletion procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	C	If it is present in the corresponding PBU, set to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
IPv4 Home Address Reply Option	C	If it is present in the corresponding PBU, set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN and Prefix-len to a non-zero value received in the corresponding PBU.	IETF RFC 5844 [5]
IPv4 Default Router Address Option	C	This option shall be present if and only if IPv4 Home Address Reply Option is present and PBU is accepted. The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code	Subclause 12.1.1.1
PDN connection ID	C	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
Access Network Identifier Option	O	Contains the access network identifier option received in PBU with the sub-options accepted (on S2a when TWAN access is used)	IETF RFC 6757 [37] IETF RFC 7563 [41]
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.4.2 MAG procedures

A MAG initiating the PMIPv6 Initial MAG Initiated PDN Connection Deletion procedure shall follow the "Mobile Node Detachment and Binding De-Registration" procedure described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications, while parameters in the PBU are set as specified by the PBU parameters section for this procedure.

5.4.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Binding De-Registration" procedure described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications, while parameters in the PBA are set as specified by the PBA parameters section for this procedure.

5.5 Proxy Mobile IPv6 LMA Initiated PDN Connection Deletion procedure

5.5.1 General

In EPC the PMIPv6 LMA Initiated PDN Connection Deletion is initiated by the node acting as a LMA to notify the node acting as a MAG, that the Binding Cache Entry related to the UE is about to be deactivated, so the MAG should remove the resources related to that PDN connection. The procedure starts with the LMA sending a BRI to the MAG to revoke the binding. The MAG confirms the revocation of the binding by sending a BRA to the LMA.

The LMA Initiated PDN Connection Deletion Procedure initiated by the LMA achieves the following:

– IPv6 Home Network Prefix release: When the UE’s PDN connection is deactivated, the LMA returns the IPv6 Home Network Prefix assigned to the UE’s PDN connection to the pool of free IPv6 Home Network Prefixes.

– IPv4 Home Address release: When the UE’s PDN connection is deactivated, the LMA returns the IPv4 Home Address assigned to the UE’s PDN connection to the pool of free IPv4 Home Network Addresses.

– Downlink and Uplink GRE keys de-assignment: The MAG and LMA will return, respectively, the PDN connection’s uplink and downlink GRE keys to their respective pool of free GRE keys.

– GRE tunnel Deletion: The GRE tunnel is removed from the LMA and the MAG.

– BCE Deletion: The LMA deletes the BCE for the PDN connection.

– BULE Deletion: The MAG deletes the BULE for the PDN connection.

5.5.1.1 Binding Revocation Indication

The fields of a BRI message for the PMIPv6 LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.5.1.1-1.

The Mobility Options in a BRI message for the LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.5.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Table 5.5.1.1-1: Fields of a BRI message for the PMIPv6

Information element	IE Description	Reference
Revocation Trigger	Set to a value indicating the event which triggered the revoking node to send the BRI message	IETF RFC 5846 [6]
Sequence Number	A sequence number generated by the LMA, and increased for every BRI sent.	IETF RFC 5846 [6]
Proxy Binding Flag (P)	Set to "1" to indicate that the Binding Revocation Indication is for a proxy MIPv6 binding entry.	IETF RFC 5213 [4]
IPv4 HoA Binding Only (V)	Set to "0" to request for complete binding revocation	IETF RFC 5846 [6]
Global Per-Peer Bindings (G)	Set to 0 to indicate that the request is for a specific PMIPv6 BCE.	IETF RFC 5846 [6]

Table 5.5.1.1-2: Mobility Options in a BRI message for the PMIPv6 LMA Initiated PDN Connection Deletion

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003[12].	IETF RFC 5213 [4], 3GPP TS 23.003[12]
IPv6 Home Network Prefix option	C	Set the Home Network Prefix to the Home Network Prefix of the UE’s PDN connection. Set the Prefix Length to the value "64". NOTE 1.	IETF RFC 5213 [4]
IPv4 Home Address Request option	C	Set the IPv4 Home Address to the IPv4 home address of the UE’s PDN connection. Set the Prefix-len to the non-zero value which was sent to the MAG at PMIPv6 PDN connection creation procedure or Handover procedure. NOTE 1.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 2.	IETF RFC 5149[11]
Protocol Configuration Options	O	Contain Protocol Configuration Options.	Subclause 12.1.1.0
PDN connection ID	C	Contains the PDN connection ID if the BCE contains the PDN Connection ID.	Subclause 12.1.1.15
3GPP Specific PMIPv6 Error Code	O	For the S5/S8 and S2a/S2b interfaces, contain 3GPP Specific PMIPv6 Error Code.	Subclause 12.1.1.1
NOTE 1: At least one of the two options, namely, the IPv6 Home Network Prefix option or the IPv4 Home Address Request option shall be present. If the UE has both IPv4 home address and IPv6 home network prefix registered, both the IPv6 Home Network Prefix option and IPv4 Home Address Request option shall be included in the same BRI message. NOTE 2: The APN field is not encoded as a dotted string as commonly used in documentation.

5.5.1.2 Binding Revocation Acknowledgment

The fields of a BRA message for the PMIPv6 LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.5.1.2-1.

The Mobility Options in a BRA message for the LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.5.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.5.1.2-1: Fields of a BRA message for a PMIPv6 LMA Initiated PDN Connection Deletion

Information element	IE Description	Reference
Status	Indicates the result of the BRI	IETF RFC 5846 [6]
Sequence Number	Set to the value received in the corresponding BRI.	IETF RFC 5846 [6]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Revocation Acknowledgment is for a proxy MIPv6 binding entry.	IETF RFC 5213 [4]
IPv4 HoA Binding Only (V)	Set to "0"; the same value as for BRI	IETF RFC 5846 [6]
Global Per-Peer Bindings (G)	Set to "0"; the same value as for the BRI.	IETF RFC 5846 [6]

Table 5.5.1.2-2: Mobility Options in a BRA message for the PMIPv6 LMA Initiated PDN Connection Deletion

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of BRI.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	C	Set the Home Network Prefix to the IPv6 Home Network Prefix of the UE’s PDN connection received in BRI. Set the Prefix Length to the value "64".	IETF RFC 5213 [4]
IPv4 Home Address Reply Option	C	Set the IPv4 Home Address to the IPv4 home address of the UE’s PDN connection received in BRI. Set the Prefix-len to the non-zero value received in BRI.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the BRI message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
Protocol Configuration Options	O	Contain Protocol Configuration Options	Subclause 12.1.1.0
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1
PDN connection ID	C	Contains the PDN connection ID received in BRI	Subclause 12.1.1.15
Access Network Identifier Option	O	The TWAN shall include the access network identifier on S2a.	IETF RFC 6757 [37]
Access Network Identifier Timestamp	O	The TWAN shall include the timestamp on the S2a interface if the Access Network Identifier option is present. It shall indicate the time when the TWAN acquired the Access Network Identifier.	Subclause 12.1.1.24
UE Time Zone	O	The TWAN shall include the UE Timezone on the S2a interface.	Subclause 12.1.1.23
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.5.2 MAG procedures

The MAG shall follow the "Local Mobility Anchor Revokes a PMIPv6 Binding" procedure described in the IETF RFC 5846 [6]. The MAG should release the resources associated with the UE’s PDN connection referred to in the BRI message.

The MAG shall respond with a BRA.

5.5.3 LMA procedures

The LMA shall send a BRI to the MAG as described in the "Local Mobility Anchor Revokes a PMIPv6 binding" procedure described in the IETF RFC 5846 [6]. The LMA shall clear the BCE related to the UE’s PDN connection after sending the BRI in case of UE detach.

5.6 Proxy Mobile IPv6 PDN Connection IPv4 address allocation procedure

5.6.1 General

The IPv4 address allocation procedure is initiated by the node acting as a MAG when DHCPv4 message is received from the UE which requires a new IPv4 address. The MAG sends a PBU to LMA requesting a new IPv4 address for an existing PDN connection. The LMA assigns a new IPv4 address by sending a PBA to the MAG. IPv4 address assignment procedure achieves the following:

– IPv4 Home Address assignment: The LMA assigns to the UE’s PDN connection an IPv4 Home Address valid in the selected PDN.

5.6.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 PDN Connection IPv4 address allocation procedure are depicted in Table 5.6.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 PDN Connection IPv4 address allocation procedure are depicted in Table 5.6.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.6.1.1-1: Fields of a PBU message for the PMIPv6 PDN Connection IPv4 address allocation procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.6.1.1-2: Mobility Options in a PBU message for the PMIPv6 PDN Connection IPv4 address allocation procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003 [12].	IETF RFC 5213 [4], 3GPP TS 23.003 [12]
IPv6 Home Network Prefix option	M	Set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN and Prefix Length to the value "64".	IETF RFC 5213 [4]
Link-local Address	M	Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "5" to indicate handoff state not changed (Re-registration).	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e., to GERAN, UTRAN,E-UTRAN or NB-IoT, or to the value matching the characteristics of the non-3GPP access (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile IPv6 Parameters Registry [18]. NOTE 1	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
IPv4 Home Address Request option	M	For dynamic allocation, set the IPv4 Home Address to the value "0.0.0.0" and Prefix-len to the value "0" or "32" to request allocation for the UE’s PDN connection of an IPv4 Home Address in the PDN corresponding to the EPS Access Point Name. For static allocation, set the IPv4 Home Address to the received static allocated IPv4 Home Address and Prefix-len to the value "32".	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 2.	IETF RFC 5149[11]
PDN connection ID	C	Contains the PDN connection ID if the BULE contains the PDN Connection ID.	Subclause 12.1.1.15
NOTE 1: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types. NOTE 2: The APN field is not encoded as a dotted string as commonly used in documentation.

5.6.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 PDN Connection IPv4 address allocation procedure are depicted in Table 5.6.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 PDN Connection IPv4 address allocation procedure are depicted in Table 5.6.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.6.1.2-1: Fields of a PBA message for the PMIPv6 PDN Connection IPv4 address allocation procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to the granted number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.6.1.2-2: Mobility Options in a PBA message for the PMIPv6 PDN Connection IPv4 address allocation procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
IPv6 Home Network Prefix option	M	Set the Home Network Prefix to the IPv6 Home Network Prefix allocated to the UE’s PDN connection based on the selected PDN and Prefix Length to the value "64".	IETF RFC 5213 [4]
Link-local Address	M	Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
IPv4 Home Address Reply option	M	Set the IPv4 Home Address to the IPv4 Home Address allocated for the UE’s PDN connection based on the selected PDN corresponding to the EPS Access Point Name for dynamic allocation, or set to the static IPv4 Home Address received in the PBU for static allocation. The Prefix-len is set to a non-zero value.	IETF RFC 5844 [5]
IPv4 Default Router Address Option	M	The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1
PDN connection ID	C	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.6.2 MAG procedures

The MAG initiating IPv4 Address Allocation using DHCPv4 procedure shall follow the "Extending Binding Lifetime" procedure described in the PMIPv6 [4] and "DHCP Relay Agent co-located with MAG" or "DHCP Server co-located with MAG" procedure as described in IPv4 support for PMIPv6 [5] specifications, while parameters in the PBU are set as specified by the PBU parameters section for this procedure.

1. If the static IPv4 Home Address is available at the MAG, set it in the IPv4 home address Request option in the PBU.

2. Set other parameters in the PBU as specified by the PBU parameters section for this procedure.

5.6.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Binding Lifetime Extension without Handover" procedures as described in the PMIPv6 [4] and IPv4 support for PMIPv6 [5] specifications with the following additional requirements:

1. Check if the received IPv4 Home address is topologically correct.

2. Allocate an IPv4 Home Address for the selected PDN.

3. Set parameters in the PBA as specified by the PBA parameters section for this procedure.

5.7 Proxy Mobile IPv6 LMA Initiated IPv4 Address Release procedure

5.7.1 General

In the case when UE is assigned both IPv6 HNP and IPv4 Home Address, if IPv4 Address lease expires or DHCPv4 Release procedure, the node acting as LMA initiates IPv4 Address Release procedure to notify the node acting as MAG about release of IPv4 address of UE for a certain PDN connection. LMA indicates MAG by sending a BRI and MAG confirms by replying with a BRA as described in IETF RFC 5846 [6].

LMA Initiated IPv4 Address Release procedure achieves the following:

– IPv4 Home Address release: The LMA returns the IPv4 Home Address assigned to the UE’s PDN connection to the pool of free IPv4 Home Network Addresses.

5.7.1.1 Binding Revocation Indication

The fields of a BRI message for the PMIPv6 LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.7.1.1-1.

The Mobility Options in a BRI message for the LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.7.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Table 5.7.1.1-1: Fields of a BRI message for the LMA Initiated IPv4 Address Release

Information element	IE Description	Reference
Revocation Trigger	Set to a value indicating the event which triggered the revoking node to send the BRI message.	IETF RFC 5846 [6]
Sequence Number	A sequence number generated by the LMA, and increased for every BRI sent.	IETF RFC 5846 [6]
Proxy Binding Flag (P)	Set to "1" to indicate that the Binding Revocation Indication is for a proxy MIPv6 binding entry.	IETF RFC 5213 [4]
IPv4 HoA Binding Only (V)	Set to "1" to revoke IPv4 address only	IETF RFC 5846 [6]
Global Per-Peer Bindings (G)	Set to 0 to indicate that the request is for a specific PMIPv6 BCE.	IETF RFC 5846 [6]

Table 5.7.1.1-2: Mobility Options in a BRI message for the LMA Initiated IPv4 Address Release

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003[12].	IETF RFC 5213 [4], 3GPP TS 23.003[12]
IPv4 Home Address Request option	M	Set the IPv4 Home Address to the IPv4 home address of the UE’s PDN connection and Prefix-len to the non-zero value which was sent to the MAG at PMIPv6 PDN connection creation procedure or Handover procedure.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
PDN connection ID	C	Contains the PDN connection ID if the BCE contains the PDN Connection ID.	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.7.1.2 Binding Revocation Acknowledgment

The fields of a BRA message for the PMIPv6 LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.7.1.2-1.

The Mobility Options in a BRA message for the LMA Initiated PDN Connection Deletion procedure are depicted in Table 5.7.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.7.1.2-1: Fields of a BRA message for a LMA Initiated IPv4 Address Release

Information element	IE Description	Reference
Status	Indicates the result of the BRI	IETF RFC 5846 [6]
Sequence Number	Set to the value received in the corresponding BRI.	IETF RFC 5846 [6]
Proxy Binding Flag (P)	Set to "1" to indicate that the Binding Revocation Indication is for a proxy MIPv6 binding entry.	IETF RFC 5213 [4]
IPv4 HoA Binding Only (V)	Set to "1"; the same value as for BRI	IETF RFC 5846 [6]
Global Per-Peer Bindings (G)	Set to 0 to indicate that the request is for a specific PMIPv6 BCE.	IETF RFC 5846 [6]

Table 5.7.1.2-2: Mobility Options in a BRA message for the LMA Initiated IPv4 Address Release

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of BRI.	IETF RFC 5213 [4] , 3GPP TS 23.003 [12]
IPv4 Home Address Reply Option	M	Set the IPv4 Home Address to the IPv4 home address of the UE’s PDN connection received in BRI. Set the Prefix-len to the non-zero value received in BRI.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the BRI message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149[11]
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8)	Subclause 12.1.1.1
PDN connection ID	C	Contains the PDN connection ID received in BRI	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.7.2 MAG procedures

The MAG shall follow the procedure for Revocation Trigger in BRI as "IPv4 HoA only" in "Binding Revocation Responder" sub-section of "Mobile Access Gateway" described in the IETF RFC 5846 [6]. The MAG shall respond with a BRA. BRA message parameters are set as per the details in BRA section of the procedure.

5.7.3 LMA procedures

The LMA shall send a BRI to the MAG as described for revoking IPv4 address only in the "Binding Revocation Initiator" sub-section of "Local Mobility Anchor" described in the IETF RFC 5846 [6]. The LMA shall delete the IPv4 Address from corresponding BCE related to the UE’s PDN connection after recieving the BRA in reply to the BRI sent from LMA. BRI message parameters are set as per the details in BRI section of the procedure.

5.8 Proxy Mobile IPv6 Multiple PDN Extensions

5.8.1 General

In EPC a UE can connect or disconnect to multiple distinct PDNs in an independent manner. Thus a distinct PMIPv6 BCE and BULE exist for each of the PDN connections of an UE.

Supporting multiple PDN connections to the same APN function is optional for MAG and LMA. A MAG which supports the multiple PDN connections to the same APN function shall include PDN connection ID in the PBU message at initial attach/handover procedure. If the LMA supports the multiple PDN connections to the same APN function, it shall include the received PDN connection ID in the PBA message. If the LMA does not support the multiple PDN connections to the same APN function, it shall ignore the received PDN connection ID and shall not include the PDN connection ID in the PBA message. If the received PBA message does not contain a PDN connection ID, the MAG shall not send any PBU message for additional PDN connectivity request to the same APN for the same UE.

5.8.2 Extensions to PMIPv6 Data Structure

There shall be a unique BCE and BULE for each PDN connection. Each PDN connection can be uniquely identified by MN ID, an APN, and optionally a PDN connection ID in the BCE and BULE.

To support Multiple PDNs the MAG and LMA maintains extended data structure compared to the standard PMIPv6 as defined in IETF RFC 5213 [4]. Since multiple PDN connections of a UE can be distinguised based on an APN, both the BCE on the LMA and the BULE on the MAG need to be extended with the following additional field:

– APN of a UE’s PDN connection.

Moreover, to support multiple PDN connections to the same APN function, the MAG and LMA shall maintain extended data structure compared to the PMIPv6 data structure described above. This extension is only applicable if multiple PDN connections to the same APN function is supported by both MAG and LMA.

Since the multiple PDN connections with the same APN of a UE shall be distinguished based on MN ID, an APN, and a PDN connection ID, both the BCE on the LMA and the BULE on the MAG need to be extended with the following additional field:

– PDN connection ID of a UE’s PDN connection. The PDN connection ID is provided by the MAG to the LMA at PDN Connection Creation procedure or Handover procedure. For S2a/S2b interface, the MAG generates the PDN connection ID which shall be unique per MN-ID per APN. How the MAG generates the PDN Connection ID for the S2a and S2b reference points is out of scope of 3GPP. For S5/S8 interface, the MAG uses the EPS bearer identity of the default bearer as PDN connection ID.

5.8.3 Extensions to PMIPv6 BULE and BCE Lookups

5.8.3.1 General

To support Multiple PDNs the MAG and LMA perform extended lookups on the extended data structure compared to the standard PMIPv6 as defined in IETF RFC 5213 [4].

In standard PMIPv6 as defined in IETF RFC 5213 [4], a PMIPv6 BCE/BULE is looked up based on the Mobile Node Identifier (MN-Id), the access technology types (ATT) and if it exist the MN’s link-layer identifier (MN-LL-Id).

In EPC the MN-LL-Id is not used and the EPC support handover between different interfaces for handover between non-3GPP and 3GPP accesses.

Distinct PMIPv6 BCE and BULE exist for each of the PDN connections of an UE.

The feature of having multiple PDN connections to the same APN is only supported if both MAG and LMA support it.

5.8.3.2 Extensions to PMIPv6 BCE Lookups

If the multiple PDN connections to the same APN feature is not supported, all PDN connections of a UE can be distinguished based on an APN and there is a one-to-one mapping between a PMIPv6 BCE, a PDN connection, and the (MN-Id, APN) tuple. An UE PDN connection can be uniquely identified by a (MN-Id, APN) tuple, the BCE is accordingly looked up on a per (MN-Id, APN) tuple basis.

If the multiple PDN connections to the same APN feature is supported, the LMA shall store the received PDN connection ID in the BCE. There is a one-to-one mapping between a PMIPv6 BCE, a PDN connection, and the (MN-Id, APN, PDN connection ID) tuple. Thus, an UE PDN connection can be uniquely identified by a (MN-Id, APN, PDN connection ID) tuple. The BCE is accordingly looked up as follows:

– If a PDN connection ID is received in the request message, the PMIPv6 BCE is looked up based on the (MN-Id, APN, PDN connection ID) tuple. If no existing binding is found based on the (MN-Id, APN, PDN connection ID) tuple, the LMA shall re-perform the PMIPv6 BCE lookup based on a per (MN-Id, APN) tuple.

– If a PDN connection ID is not received in the request message, the PMIPv6 BCE lookup is based on a per (MN-Id, APN) tuple.

5.8.3.3 Extensions to PMIPv6 BULE Lookups

If the multiple PDN connections to the same APN feature is not supported, an UE PDN connection can be uniquely identified by a (MN-Id, APN) tuple. In this case the BULE is accordingly looked up on a per (MN-Id, APN) tuple basis.

If the multiple PDN connections to the same APN feature is supported, the MAG shall generate a PDN connection ID per PDN connection and store it in the BULE. Thus, there is a one-to-one mapping between a PMIPv6 BULE, a PDN connection, and the (MN-Id, APN, PDN connection ID) tuple. An UE PDN connection can be uniquely identified by a per (MN-Id, APN, PDN connection ID) tuple. The BULE is accordingly looked up on a per (MN-Id, APN, PDN connection ID) tuple basis.

5.8.4 Extensions to PMIPv6 Procedure

5.8.4.1 General

The processing rules on the received PMIPv6 message are specified in IETF RFC 5213 [4] and IETF RFC 5844 [5]. This subclause specifies the additional PMIPv6 procedures.

5.8.4.2 MAG procedure

If the PMIPv6 PBU retransmission is triggered, a PMIPv6 PBU message with identical mobility options, except the value of the Timestamp option is new, shall be sent.

5.8.4.3 LMA procedure

If before responding to a received PMIPv6 PBU message, a new PMIPv6 PBU message with the same MN-ID, APN (and PDN connection ID) mobility options is received, then the LMA may respond to one or all of the received PMIPv6 PBU messages.

If the LMA receives a PMIPv6 PBU message with HI = 1 from the same MAG and an existing BCE with the same MN-ID, APN (and PDN connection ID) is found, the LMA may refresh the BCE or release the old BCE and create a new one based on the received PBU message.

5.9 Serving GW Procedure at Chaining Case

5.9.1 General

Chained S2a/S2b with GTP-based S8 is not supported in this release.

Chained S2a/S2b with PMIP-based S8 is used when VPLMN has business relationship with Non-3GPP Networks and Serving GW in VPLMN supporting a LMA function as local non-3GPP Anchor.

5.9.2 Signalling procedures

When either of the S2a or S2b interfaces is chained with a PMIP-based S8 interface, the Serving GW acts as the signaling endpoint for each interface. On the S2a or S2b interface, the Serving GW acts as an LMA. On the chained PMIP-based S8 interface, the Serving GW acts as MAG. When a procedure is initiated by its peer on a given interface for a given PDN connection, the Serving GW shall trigger an equivalent procedure over the chained interface for the designated PDN connection. The procedure initiated by its peer cannot be completed before the completion of the equivalent procedure initiated over the chained interface.

5.9.2.1 PMIP-based S8 Serving GW procedures

Upon receiving a PMIPv6 message over S8 for an LMA initiated procedure for a given PDN connection, the Serving GW shall initiate the corresponding LMA procedure over S2a or S2b for the designated PDN connection.

Upon receiving a PMIPv6 message over S2a or S2b for a MAG initiated procedure for a given PDN connection, the Serving GW shall initiate the corresponding MAG procedure over PMIP-based S8 for the designated PDN connection.

Table 5.9.2.1-1: procedure, message and IE mapping at PMIPv6 based S8

Initiated procedure	Messages	Initiating interface	Chained interface	Corresponding procedure Chained interface	Corresponding messages
PDN Connection Creation as specified in subclause 5.1	PBU/PBA	S2a or S2b	PMIPv6 based S8	PDN Connection Creation as specified in subclause 5.1	PBU/PBA
PDN Connection Lifetime Extension as specified in subclause 5.2	PBU/PBA	S2a or S2b	PMIPv6 based S8	PDN Connection Lifetime Extension as specified in subclause 5.2	PBU/PBA
PDN Connection Handover as specified in subclause 5.3	PBU/PBA	S2a or S2b	PMIPv6 based S8	PDN Connection Handover as specified in subclause 5.3	PBU/PBA
MAG Initiated PDN Connection Deletion as specified in subclause 5.4	PBU/PBA	S2a or S2b	PMIPv6 based S8	MAG Initiated PDN Connection Deletion as specified in subclause 5.4	PBU/PBA
LMA Initiated PDN Connection Deletion as specified in subclause 5.5	BRI/BRA	PMIPv6 based S8	S2a or S2b	LMA Initiated PDN Connection Deletion as specified in subclause 5.5	BRI/BRA

5.9.3 Payload packets at chained case

When the S2a or S2b interfaces is chained with a PMIP-based S8 interface, both uplink and downlink payload packets are forwarded by the Serving GW between the S2a or S2b PMIPv6 GRE tunnel and the S8 PMIPv6 GRE tunnel for a given PDN connection.

5.10 Proxy Mobile IPv6 MAG Initiated IPv4 Address Release procedure

5.10.1 General

In the case when UE is assigned both IPv6 HNP and IPv4 Home Address, for DHCPv4 Release procedure, the node acting as MAG initiates the selective de-registration of IPv4 home address procedure to notify the node acting as LMA about release of IPv4 address of UE for a certain PDN connection. MAG notifies LMA by sending a PBU and LMA confirms by replying with a PBA as described in IETF RFC 5844 [5]. IPv4 address release procedure achieves the following:

IPv4 Home Address release: The LMA releases an IPv4 Home Address of the UE’s PDN connection.

5.10.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 MAG Initiated IPv4 Address Release procedure are depicted in Table 5.10.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 MAG Initiated IPv4 Address Release procedure are depicted in Table 5.10.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.10.1.1-1: Fields of a PBU message for the PMIPv6 MAG Initiated IPv4 Address Release procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to "0" to request deletion of the IPv4 binding.	IETF RFC 5844 [5]

Table 5.10.1.1-2: Mobility Options in a PBU message for the PMIPv6 MAG Initiated IPv4 Address Release procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the NAI identifier of the UE as specified in 3GPP TS 23.003 [12].	3GPP TS 23.003 [12]
Handoff Indicator option	M	Set to the value "4" to indicate Handoff state unknown.	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the value matching the characteristics of the non-3GPP access on S2a (e.g., HRPD) the UE is using to attach to the EPS as defined in the Access Technology Type Option type values registry of the IANA Mobile IPv6 Parameters Registry [18]. NOTE 1	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
IPv4 Home Address Request option	M	Set the IPv4 Home Address to the IPv4 Home Address to be released of the UE’s PDN connection and Prefix-len to the non-zero value received from LMA.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached, formatted as defined in 3GPP TS 23.003 [12]	IETF RFC 5149[11]
NOTE 1: The PDN-GW can be informed about the type of access network used by the UE over several reference points, see 3GPP TS 29.212 [30] for the mapping between the code values for the different access network types.

5.10.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 MAG Initiated IPv4 Address Release procedure are depicted in Table 5.10.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 MAG Initiated IPv4 Address Release procedure are depicted in Table 5.10.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.10.1.2-1: Fields of a PBA message for the PMIPv6 MAG Initiated IPv4 Address Release procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to "0" to request deletion of the IPv4 binding.	IETF RFC 5844 [5]

Table 5.10.1.2-2: Mobility Options in a PBA message for the PMIPv6 MAG Initiated IPv4 Address Release procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
IPv4 Home Address Reply Option	M	Set the IPv4 Home Address to the released IPv4 Home Address of the UE’s PDN connection and Prefix-len to the non-zero value received in BRI.	IETF RFC 5844 [5]
IPv4 Default Router Address Option	M	The LMA sets the value of the UE’s IPv4 default router address which belongs to the same subnet as the IPv4 Home Address allocated to the UE.	IETF RFC 5844 [5]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message, formatted as defined in 3GPP TS 23.003 [12]	IETF RFC 5149[11]
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1

5.10.2 MAG procedures

The MAG initiating IPv4 Address Release using DHCPv4 procedure shall follow the "Selective De-Registration" procedure and "DHCP Server co-located with MAG" procedure as described in IPv4 support for PMIPv6 [5] specifications, while parameters in the PBU are set as specified by the PBU parameters section for this procedure.

1. Set the IPv4 home address to be released in the IPv4 home address Request option in the PBU.

2. Set other parameters in the PBU as specified by the PBU parameters section for this procedure.

5.10.3 LMA procedures

On reception of a PBU, the LMA shall initiate the "Selective De-Registration" procedures as described in the IPv4 support for PMIPv6 [5] specifications with the following additional requirements:

1. Release the IPv4 Home Address corresponding to the IPv4 home address Request option in the PBU message.

2. Set parameters in the PBA as specified by the PBA parameters section for this procedure.

5.11 Proxy Mobile IPv6 LMA Initiated Update Notification procedure

5.11.1 General

In EPC the PMIPv6 LMA Initiated Update Notification procedure is initiated by the node acting as a LMA to notify the node acting as a MAG, that the Binding Cache Entry related to the UE is about to be updated, so the MAG updates the resources related to that PDN connection. The procedure starts with the LMA sending a PMIPv6 UPN message to the MAG. The MAG confirms by sending a PMIPv6 UPA message to the LMA.

The PMIPv6 LMA Initiated Update Notification procedure is initiated by the node acting as a LMA to notify the node acting as a MAG, to trigger the generation of End Marker by the MAG. The procedure starts with the LMA sending a PMIPv6 UPN message to the MAG. The LMA shall not request an acknowledgement message from the MAG. See clause 15.

This PMIPv6 LMA Initiated Update Notification procedure is based on the PMIPv6 notification procedure as specified in the IETF RFC 7077 [35].

5.11.1.1 Update Notification

The fields of a UPN message for the PMIPv6 LMA Initiated Update Notification procedure are depicted in Table 5.11.1.1-1.

The Mobility Options in a UPN message for the PMIPv6 LMA Initiated Update Notification procedure are depicted in Table 5.11.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver shall ignore all other instances.

Other flags are not used by this specification.

Table 5.11.1.1-1: Fields of a UPN message for the PMIPv6 LMA Initiate Update Notification procedure

Information element	Description	Reference
Sequence Number	Set to a locally (i.e. per LMA) monotonically increasing value.	IETF RFC 5213 [4]
Notification Reason	Set to the corresponding notification reason	IETF RFC 7077 [35]
Acknowledge (A)	Set to "1" to request an acknowledgement message. Set to "0" not to request an acknowledgement message.	IETF RFC 7077 [35]

Table 5.11.1.1-2: Mobility Options in a UPN message for the PMIPv6 LMA Initiated Update Notification procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the NAI identifier of the UE as specified in 3GPP TS 23.003 [12].	3GPP TS 23.003 [12]
Service Selection Mobility Option	O	This IE shall be set to the EPS Access Point Name to which the UE’s PDN connection is attached.	IETF RFC 5149 [11]
PDN connection ID	O	This IE shall contain the PDN connection ID if the BCE contains the PDN Connection ID.	Subclause 12.1.1.15
MME/SGSN Identifier	O	Contains the MME/S4-SGSN identifier	Subclause 12.1.1.20
Protocol Configuration Option	O	Contains Protocol Configuration Options.	Subclause 12.1.1.0
End Marker Notification	O	Contains the End Marker Notification (on S5/S8).	Subclause 12.1.1.21
PDN GW IP Address	O	Contains PDN GW IP address for control plane used by the PDN connection.	Subclause 12.1.1.4
GRE key option	O	Contains the uplink GRE key for control plane used by the PDN connection.	IETF RFC 5845 [7]
Additional Protocol Configuration Option	O	Contains Additional Protocol Configuration Options.	Subclause 12.1.1.19

5.11.1.2 Update Notification Acknowledgement

The fields of a UPA message for the PMIPv6 LMA Initiated Update procedure are depicted in Table 5.11.1.2-1.

The Mobility Options in a UPA message for the PMIPv6 LMA Initiated Update procedure are depicted in Table 5.11.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver shall ignore all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.11.1.2-1: Fields of a UPA message for the PMIPv6 LMA Initiated Update Notification procedure

Information element	Description	Reference
Sequence Number	Set to the value received in the corresponding UPN.	IETF RFC 5213 [4]
Status	Indicates the result of the UPN	IETF RFC 7077 [35]

Table 5.11.1.2-2: Mobility Options in a UPA message for the PMIPv6 LMA Initiated Update Notification procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from the corresponding field in the UPN.	3GPP TS 23.003 [12]
Service Selection Mobility Option	O	This IE shall be copied from the corresponding field in the UPN message if present.	IETF RFC 5149 [11]
PDN connection ID	C	Contains the PDN connection ID received in UPN	Subclause 12.1.1.15
3GPP Specific PMIPv6 Error Code	O	Contains a 3GPP Specific PMIPv6 Error Code.	Subclause 12.1.1.1

5.11.2 LMA procedures

A LMA initiating the PMIPv6 LMA Initiated Update Notification procedure shall follow the procedure described in IETF RFC 7077 [35], while parameters in the UPN message are set as specified by the UPN message parameters section for this procedure.

5.11.3 MAG procedures

On reception of a UPN, the MAG shall follow the procedure described in IETF RFC 7077 [35], while parameters in the UPA message are set as specified by the UPA message parameters section for this procedure.

5.12 Proxy Mobile IPv6 Mobile Network Prefix Allocation procedure

5.12.1 General

Proxy Mobile IPv6 Mobile Network Prefix Allocation procedure is initiated by the node acting as a MAG when DHCPv6 Reply message is received from the node acting as a LMA which is co-located with delegating router if the UE requests a network prefix shorter than the default /64 prefix (i.e. prefixes in addition to the default prefix) as specified in 3GPP TS 23.402 [3]. The MAG sends a PBU to LMA associating the network prefix with an existing PDN connection. The LMA confirms the assigned network prefix by sending a PBA to the MAG. Proxy Mobile IPv6 Mobile Network Prefix Allocation achieves the following:

– Delegated Mobile Network Prefix assignment: The LMA assigns to the UE’s PDN connection the mobile network prefix shorter than the default /64 prefix valid in the selected PDN.

– BCE Update: The LMA includes the delegated mobile network prefix in the BCE for the PDN connection.

– BULE Update: The MAG includes the delegated mobile network prefix in the BULE for the PDN connection.

5.12.1.1 Proxy Binding Update

The fields of a PBU message for the PMIPv6 Mobile Network Prefix Allocation procedure are depicted in Table 5.12.1.1-1.

The Mobility Options in a PBU message for the PMIPv6 Mobile Network Prefix Allocation procedure are depicted in Table 5.12.1.1-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Table 5.12.1.1-1: Fields of a PBU message for the PMIPv6 Mobile Network Prefix Allocation procedure

Information element	IE Description	Reference
Sequence Number	Set to a locally (i.e. per MAG) monotonically increasing value.	IETF RFC 5213 [4]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate that UDP encapsulation is not used for the user plane.	IETF RFC 5555 [34]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.12.1.1-2: Mobility Options in a PBU message for the PMIPv6 Mobile Network Prefix Allocation procedure procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Set to the UE NAI that is derived from the UE IMSI if an authenticated IMSI is available, or from the UE IMEI if IMSI is not available or the IMSI is not authenticated by the network. The NAI format is specified in 3GPP TS 23.003 [12].	IETF RFC 5213 [4], 3GPP TS 23.003 [12]
Delegated Mobile Network Prefix Option	M	Set the Delegated Mobile Network Prefix Option to the mobile network prefix allocated to the UE’s PDN connection.	IETF RFC 7148 [45]
Link-local Address	M	Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Set to the value "5" to indicate handoff state not changed (Re-registration).	IETF RFC 5213 [4]
Access Technology Type option	M	Set to the 3GPP access type, i.e., to GERAN, UTRAN or E-UTRAN.	IETF RFC 5213 [4]
Timestamp option	M	Set to the current time	IETF RFC 5213 [4]
Service Selection Mobility Option	M	Set to the EPS Access Point Name to which the UE’s PDN connection is attached. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149 [11]
PDN connection ID	C	Contains the PDN connection ID if the BULE contains the PDN Connection ID.	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.12.1.2 Proxy Binding Acknowledgement

The fields of a PBA message for the PMIPv6 Mobile Network Prefix Allocation procedure are depicted in Table 5.12.1.2-1.

The Mobility Options in a PBA message for the PMIPv6 Mobile Network Prefix Allocation procedure are depicted in Table 5.12.1.2-2. When the mobility option is present in the message, only the first instance shall be recognised. If multiple instances are included in the message, the receiver ignores all other instances.

Other flags are not used by this specification.

Only the message fields and mobility options used for acceptance cases are present in the following tables.

Table 5.12.1.2-1: Fields of a PBA message for the PMIPv6 Mobile Network Prefix Allocation procedure

Information element	IE Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [8]
Proxy Registration Flag (P)	Set to "1" to indicate that the Binding Update message is a proxy registration.	IETF RFC 5213 [4]
Sequence Number	Set to the value received in the corresponding PBU.	IETF RFC 5213 [4]
Lifetime	Set to the granted number of time units the binding shall remain valid.	IETF RFC 6275 [8]

Table 5.12.1.2-2: Mobility Options in a PBA message for the PMIPv6 Mobile Network Prefix Allocation procedure

Information element	Cat.	IE Description	Reference
Mobile Node Identifier option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Delegated Mobile Network Prefix Option	M	Copied from corresponding field of PBU.	IETF RFC 7148 [45]
Link-local Address	M	Set to the link-local address already allocated to the MAG (in the previous initial binding registration) for use on the access link shared with the UE.	IETF RFC 5213 [4]
Handoff Indicator option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Access Technology Type option	M	Copied from corresponding field of PBU.	IETF RFC 5213 [4]
Timestamp option	M	Copied from corresponding field of PBU, or set to the current time of LMA in case of timestamp error.	IETF RFC 5213 [4]
Service Selection Mobility Option	M	Copied from the corresponding field in the PBU message. The encoding of the APN field follows 3GPP TS 23.003 [12] subclause 9.1 but excluding the trailing zero byte. The content of the APN field shall be the full APN with both the APN Network Identifier and APN Operator Identifier being present as specified in 3GPP TS 23.003 [12] subclauses 9.1.1 and 9.1.2. NOTE 1.	IETF RFC 5149 [11]
3GPP Specific PMIPv6 Error Code	O	Contain 3GPP Specific PMIPv6 Error Code (on S5/S8).	Subclause 12.1.1.1
PDN connection ID	C	Contains the PDN connection ID received in PBU	Subclause 12.1.1.15
NOTE 1: The APN field is not encoded as a dotted string as commonly used in documentation.

5.12.2 MAG procedures

The MAG initiating PMIPv6 Mobile Network Prefix Allocation using DHCPv6 prefix delegation procedure shall follow the "Delegating Router Co-located with Local Mobility Anchor" procedure as described in IETF RFC 7148 [45], while parameters in the PBU message are set as specified by the PBU message parameters section for this procedure.

5.12.3 LMA procedures

On reception of a PBU, the LMA shall initiate the " Delegating Router Co-located with Local Mobility Anchor " procedures as described described in IETF RFC 7148 [45], while parameters in the PBA message are set as specified by the PBA message parameters section for this procedure.