A.3 Re-Registration

24.3033GPPMobility management based on Dual-Stack Mobile IPv6Release 17Stage 3TS

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

A.3.1 Binding Update

The fields of a BU message for the DSMIPv6 Re-Registration procedure are depicted in Table A.3.1-1.

The Mobility Options in a BU message for the DSMIPv6 Re-Registration procedure are depicted in Table A.3.1-2.

Table A.3.1-1: Fields of a BU message for the DSMIPv6 Re-Registration procedure

Fields	Fields Description	Reference
Sequence Number	Set to a monotonically increasing value.	IETF RFC 6275 [27]
Lifetime	Set to the requested number of time units the binding shall remain valid.	IETF RFC 6275 [27]
Home Registration (H)	Set to " 1" to indicate receiving node should act as this node’s HA	IETF RFC 6275 [27]
Link-local Address Compatibility (L)	The Link-Local Address Compatibility (L) bit is set when the home address reported by the mobile node has the same interface identifier as the mobile node’s link-local address.	IETF RFC 6275 [27]
Key Management Mobility Capability (K)	Set to "1" to indicate IKEv2 SA ability to survive mobility	IETF RFC 6275 [27]
Acknowledge (A)	Set to "1" to request an acknowledgement message.	IETF RFC 6275 [27]
Force UDP encapsulation request (F) Flag	Set to "0" to indicate no forced UDP encapsulation	IETF RFC 5555 [2]
Mobile Router Flag (R)	Set to "1" to indicate home network prefix preservation for the UE.	IETF RFC 3963 [29]
Overwrite Flag (O)	Set to "0" to maintain all binding cache entries at the HA previously registered.	IETF RFC 5648 [31]

Table A.3.1-2: Mobility Options in a BU message for the DSMIPv6 Re-Registration procedure

Mobility Option	Cat.	Mobility Option Description	Reference
IPv4 Home Address option	C	If the UE has previously registered IPv4 home address and wants to keep it, it is included in the option. The "P" flag is not set. The Prefix Length is set to the requested prefix length of 32. If the UE has previously registered IPv4 home address and wants to release it, it is not included in the BU. If the UE has no IPv4 Home address it may set the value "0.0.0.0" to request allocation for the UE. In this case the "P" flag is set to "0". The Prefix Length is set to the requested prefix length of 32.	IETF RFC 5555 [2]
IPv 4 Care-of Address	C	Set to the IPv4 Care-of address (same value as was set in the Initial BU) when in an IPv4 Access Network	IETF RFC 5555 [2]
Alternate Care-of Address	C	Used (in addition to the Source address of the IPv6 packet) to carry the IPv6 care-of address when in an IPv6 access network.	IETF RFC 6275 [27]
Binding Identifier mobility option	C	The option is present if the UE included a Binding Identifier mobility option in the BU previously sent to the Home Agent. The BID and BID-PRI are set to an arbitrary value. For registration of a home link, the "H" flag is set to "1" and the value of the CoA field is the Home Address. For registration of a foreign link, the "H" flag is set to "0" and the value of the CoA field is the Care-of Address.	IETF RFC 5648 [31], IETF RFC 6089 [32]
Flow Summary mobility option	C	The option is present if the UE included a Flow Summary mobility option or at least one Flow Identification mobility option in the BU previously sent to the Home Agent. Contain one or more FIDs present in the binding update list to refresh the respective flow bindings.	IETF RFC 6089 [32]

A.3.2 Binding Acknowledgement

The fields of a BA message for the DSMIPv6 Re-Registration procedure are depicted in Table A.3.2-1.

The Mobility Options in a BA message for the DSMIPv6 Re-Registration procedure are depicted in Table A.3.2-2.

Table A.3.2-1: Fields of a BA message for the DSMIPv6 Re-Registration procedure

Fields	Fields Description	Reference
Status	Set to indicate the result.	IETF RFC 6275 [27]
Key Management Mobility Capability (K)	Set as per HA ability to support the feature of updating the IKE SA based on Binding Update processing	IETF RFC 6275 [27], IETF RFC 5555 [2]
Mobile Router Flag (R)	Set to "1"	IETF RFC 3963 [29]
Sequence Number	Set to the value received in the corresponding Binding Update or the last accepted sequence number in the case of Status 135 ("Sequence Number out of window ").	IETF RFC 6275 [27]
Lifetime	Set to the granted number of time units of 4 seconds the binding shall remain valid.	IETF RFC 6275 [27]

Table A.3.2-2: Mobility Options in a BA message for the DSMIPv6 Re-Registration procedure

Mobility Option	Cat.	Mobility Option Description	Reference
IPv4 Address Acknowledgment option	C	If IPv4 Home Address option is present in the corresponding BU, IPv4 Home Address is set to the IPv4 Home Address previously allocated for the UE or to a dynamically allocated value if the UE had no previous IPv4 home address and requested one at with the BU. The supporting Status field is set accordingly. Pref-len field is set to "32".	IETF RFC 5555 [2]
NAT Detection Option	C	When present the option contains the F Flag which indicates to the UE that UDP encapsulation is required. Option contains an optionally Refresh Time for the UE to refresh the NAT binding.	IETF RFC 5555 [2]
Binding Refresh Advice	O	Contains a Refresh Interval in units of 4 seconds indicating the remaining time until the UE should send a new home registration to the HA.	IETF RFC 6275 [27]
Binding Identifier mobility option	C	The option is present if the UE sent a Binding Identifier mobility option in the corresponding BU. The Status field is set accordingly. The BID, BID-PRI and "H" flag are set to the value indicated in the BID mobility option of the received Binding Update.	IETF RFC 5648 [31], IETF RFC 6089 [32]
Flow Identification mobility option	O	The Status field is set accordingly. The FID, FID-PRI, Action field and sub-option field are set to the value indicated in the Flow Summary mobility option of the received Binding Update.	IETF RFC 6089 [32], IETF RFC 6088 [33]