Bulk Binding Update Support for Proxy Mobile IPv6
Extracted elements (28)
Group identifiers are local to each peer and not globally unique within a PMIPv6 domain; the same value may be used by other nodes. Both peers independently assign their own group identifiers and exchange them during initial session establishment, enabling each side to initiate bulk operations using its own local identifier.
Per-session Proxy Binding Update messages for lifetime extension generate excessive signaling traffic as the number of mobility sessions grows. A bulk binding update mechanism using group identifiers allows a single PBU to refresh the lifetime of an entire group of sessions, reducing both processing and bandwidth overhead.
The Mobile Node Group Identifier option is a generic option; this specification uses only sub-type 1. Future specifications may define additional sub-types. When the LMA does not enable bulk binding update support, it MUST NOT include the option with sub-type 1, though other sub-types may appear.
A bulk binding update PBU MUST NOT include individual session identifiers such as Mobile Node Identifier option, Home Network Prefix option, IPv4 Home Address Request option, or GRE Key option.
If a bulk PBU includes individual session identifiers (MN Identifier, HNP, IPv4 HoA, or GRE Key), the LMA MUST consider it invalid, reject the PBU, and send a PBA with Status INVALID_MOBILE_NODE_GROUP_IDENTIFIER (175).
If a received Binding Revocation Indication with a Mobile Node Group Identifier option also includes individual session identifiers (MN Identifier, HNP, IPv4 HoA, GRE Key), the MAG MUST consider it invalid and MUST reject it, sending a BRA with Status 128 (Binding Does NOT Exist).
If bulk binding update support is not enabled, the LMA MUST NOT include the Mobile Node Group Identifier option with sub-type 1 in the PBA, and MUST set the (B) flag to 0.
If the Mobile Node Group Identifier option in a bulk PBU carries an unknown group identifier, the LMA MUST reject the PBU and send a PBA with Status INVALID_MOBILE_NODE_GROUP_IDENTIFIER (175).
If the PBA has (B)=1 but the Mobile Node Group Identifier option is absent, the MAG MUST consider the message malformed and ignore it.
The (B) flag in the Proxy Binding Acknowledgement MUST be set to 0 if the (B) flag in the received PBU was set to 0, and MUST be set to 0 when the (P) flag is 0.
The (B) flag in the Proxy Binding Update MUST be set to 0 when the (P) flag is 0, since the bulk binding update flag is relevant only for Proxy Mobile IPv6.
The LMA MUST associate the mobility session to a specific bulk binding update group locally when enabling bulk binding update support, and MUST include the assigned group identifier in the PBA with sub-type 1 and (B) flag set to 1.
To disable bulk binding update support, the MAG MUST send a PBU with (B)=0 and MUST NOT include the Mobile Node Group Identifier option. The Binding Update List entry group identifier values MUST be set to 0 and the session MUST be excluded from bulk operations.
Upon accepting a bulk binding update, the LMA MUST send a PBA with Status 0, include the Mobile Node Group Identifier option (sub-type 1) with the identifier copied from the request, and set the Lifetime to the allocated lifetime for all sessions in the group.
Upon completing a bulk revocation, the LMA MUST send a Binding Revocation Acknowledgement with Status 0 (success) including the Mobile Node Group Identifier option with the identifier copied from the BRI.
When a mobile node roams to a new MAG, the LMA SHOULD update the bulk binding update group identifier and MUST include the updated identifier in the PBA to the new MAG (sub-type 1), unless the new PBU did not have (B)=1, in which case the session MUST NOT be included in any bulk group.
When a mobile node's session is de-registered or revoked, the mobility session MUST be removed from the bulk binding update group.
When requesting bulk binding update support, the MAG MUST set the (B) flag to 1 and MUST include the Mobile Node Group Identifier option in the PBU. The option's sub-type MUST be set to 1 (Bulk Binding Update Group).
A Bulk Binding Update Group is a set of mobility sessions sharing a common group identifier maintained independently by both the MAG and LMA. Each peer assigns its own local group identifier, which is exchanged during initial session establishment via the Mobile Node Group Identifier option.
Both the MAG Binding Update List entry and LMA Binding Cache entry data structures are extended with two REQUIRED fields: MAG-Bulk-Binding-Update-Group-Id and LMA-Bulk-Binding-Update-Group-Id, each a 32-bit unsigned integer, not globally unique within a PMIPv6 domain.
The Mobile Node Group Identifier option's Reserved field (8 bits) MUST be initialized to 0 by the sender and MUST be ignored by the receiver. The group identifier value of 0 is reserved and SHOULD NOT be used; value 1 (ALL-SESSIONS) represents all sessions between a given MAG and LMA.
The status code INVALID_MOBILE_NODE_GROUP_IDENTIFIER (value 175) is defined for the Proxy Binding Acknowledgement message to indicate an invalid group identifier value in the request. Allocated from the same number space as RFC 6275 status codes.
A new (B) flag was allocated in the 'Binding Update Flags' registry and a new (B) flag in the 'Binding Acknowledgement Flags' registry, as defined by RFC 5213/RFC 6275 number spaces.
IANA created the 'Mobile Node Group Identifier Type Registry' for the Sub-type field of the Mobile Node Group Identifier option. Sub-type 1 (Bulk Binding Update Group) is reserved; values 0 and 255 are reserved; values 2-254 available via Expert Review.
Without proper authorization checks, a malicious node could hijack mobility sessions or conduct denial-of-service attacks by sending bulk binding update or revocation requests for groups of sessions. The LMA MUST allow only authorized MAGs to perform bulk operations to prevent such attacks.
The Mobile Node Group Identifier option (Type=50) carries a 32-bit group identifier. It includes a 1-octet Type, 1-octet Length (fixed value 6), 1-octet Sub-type, 1-octet Reserved, and a 32-bit Mobile Node Group Identifier field. Sub-type value 1 is reserved for Bulk Binding Update Group.
The Proxy Binding Acknowledgement message is extended with a new Bulk-Binding-Update flag (B) at bit value 0x08. When set to 1, it confirms the LMA has enabled bulk binding update support for the mobility session.
The Proxy Binding Update message is extended with a new Bulk-Binding-Update flag (B) at bit value 0x0040. When set to 1, it requests the LMA to enable bulk binding update support for the associated mobility session.