Mobile IP Working Group Jari T. Malinen
INTERNET DRAFT Charles E. Perkins
14 July 2000 Nokia Research Center
Category: Standards Track
Mobile IPv6 Regional Registrations
draft-malinen-mobileip-regreg6-00.txt
Status of This Memo
This document is a submission by the mobile-ip Working Group of the
Internet Engineering Task Force (IETF). Comments should be submitted
to the MOBILE-IP@STANDARDS.NORTELNETWORKS.COM mailing list.
Distribution of this memo is unlimited.
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at
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material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at:
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at:
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Abstract
This document describes Mobile IPv6 regional registration as an
optional extension to Mobile IPv6. Regional registration introduces
visited-domain mobility agent functionality for proxying a public
care-of-address which remains the same while the mobile node
moves in the visited domain. This reduces the binding update
signaling latency for the mobile node and signaling load outside the
visited domain. The protocol defines regional mobility capability
negotiation, regional binding update signaling, and regional-aware
data routing through a hierarchy of visited-domain mobility agents.
The protocol allows for an arbitrary point in the visited-domain
hierarchy to distribute the connection-state maintenance between
several mobility agents. IPSec AH is used for securing the protocol
as in basic Mobile IPv6.
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Contents
Status of This Memo 1
Abstract 1
1. Introduction 3
2. Terms 4
3. Protocol Operation Overview 5
3.1. Movement to a new Link . . . . . . . . . . . . . . . . . 7
3.2. Visited-domain capability discovery . . . . . . . . . . . 8
3.3. Regional Registrations signaling . . . . . . . . . . . . 8
3.4. Regional-Aware Data Routing . . . . . . . . . . . . . . . 10
3.4.1. Regional Forwarding of Encapsulated Packets . . . 10
3.4.2. Regional Forwarding of Route-Optimised Packets . 10
4. Protocol Extensions 11
4.1. Router Advertisement modifications . . . . . . . . . . . 11
4.2. Regional CoA Extension . . . . . . . . . . . . . . . . . 12
4.3. Regional Binding Update . . . . . . . . . . . . . . . . . 13
4.4. Previous Access Router Sub-Option . . . . . . . . . . . . 14
5. New requirements for IPv6 Nodes 15
5.1. Visited Domain Router Requirements . . . . . . . . . . . 15
5.2. Mobile Node Requirements . . . . . . . . . . . . . . . . 15
6. IANA Considerations 16
7. Security Considerations 16
8. Acknowledgements 16
Addresses 18
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1. Introduction
Mobile IPv6 regional registration reduces the binding update
signaling latency and the signaling load for a mobile node moving
within the same visited domain. The latency is reduced by localizing
binding updates to the visited domain and the signaling load is
reduced by using a regional-aware router for a proxy care-of-address,
the regional care-of-address, as seen by hosts outside the
visited domain. The protocol re-uses the general idea of regional
registrations for Mobile IPv4 [3], but is a different IPv6-specific
protocol, in data routing in particular.
The regional care-of address can be in an arbitrary node in the
visited domain, not just in an edge router or the gateway mobility
agent highest in the hierarchy. The selection of a particular
regional care-of address is done by the mobile node from a list of
addresses advertised by the access router.
The regional binding update is transported over an arbitrary-depth
tree hierarchy of regional-aware routers up to the closest possible
router in the hierarchy. This router is the crossover between the
old path from the gateway router to the previous access router and
from the gateway router to the new access router. The protocol
supports network-controlled selection of the crossover router
which hides the inner structure of the hierarchy and enables
constant-length signaling independent of the depth of the hierarchy.
The regional registration protocol does not require modifications
to any network elements other than the mobile node and the
regional-aware routers. These modifications are optional additions
to basic Mobile IPv6. Non-regional-aware routers, hosts, home
agents, and mobile nodes can interoperate with regional-aware
entitites without change.
The added routing state maintenance in the visited domain is minimal.
It does not involve the routing tables at all; all per-mobile state
is kept in the regional binding cache. This data structure is
internal to the regional mobility agent and can re-use the existing
binding cache.
Security is provided by the IPSec, thus the end-to-end security model
is not compromised. Basic Mobile IP security can thus be used for
regional registrations.
This protocol defines the regional registrations transport for IPv6
and it can be used in combination with other components of the
general smooth hand-over framework [5] for gaining cost-efficient
signaling. In such a combination, the mobile node sends the message
over the wireless interface encapsulated with the state transfer SHIN
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option up to the access router. The encapsulating header may carry
e.g. buffering [7] or header compression [6] state transfer signaling
needed for smooth and efficient handoffs.
2. Terms
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [2].
In addition, this document frequently uses the following terms:
Access Router
The closest router to the mobile node in the visited
domain that the mobile node uses to access the network.
Crossover Router
When a mobile node is performing a regional registration,
the Crossover Router is the router where the old path
leading to a mobile node and the new path cross, i.e.
the regional router in the hierarchy where a connection
state change is needed to maintain an up-to-date
communication path to the mobile node.
Gateway Mobility Agent
The software module implementing regional registrations
in the gateway router.
Gateway Router
A router controlling the regional care-of-address of a
mobile node; This is the gateway through which traffic
for the mobile node enters the visited domain.
Highest Router
Router used in a visited domain as the root of a physical
hierarchy; The gateway mobility agent can exist anywhere
in the physical hierarchy. The visible hierarchy for a
mobile node is thus rooted at the gateway router possibly
below the highest router.
Home Binding
The binding cache entry in a home agent used for storing
home registration state.
Home Registration
Sending of a binding update to the home agent to create a
home binding.
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Regional-aware Router
Router that supports regional registrations.
Regional Binding Cache
A conceptual data structure in regional-aware routers;
it is keyed on the home address of a mobile node and
contains the care-of-address, lifetime, flags, security
association, and network interface as data elements. All
regional routing state is contained in this entry.
Regional Care-of-address
A care-of-address, as seen from outside the visited
domain, used to locate a mobile node. Remains the same
while the mobile node does regional binding updates
within a visited domain.
Regional Mobility Agent
The software module implementing regional registrations
in a regional-aware router.
Visited Domain
A domain that is visited by the mobile node; A set of
subnets usually administered by one entity. In this
document, all routers in a visited domain are assumed to
have a security association with one another.
This terminology is intended to conform to those that have been
used in Mobile IP and other Internet protocols. Basic Mobile IPv6
terminology is used as defined in [4].
3. Protocol Operation Overview
A foreign domain advertises its capability for regional registrations
with a router advertisement flag. When entering a visited domain
for the first time, the mobile node registers with its home domain.
During or after this registration, the mobile node can perform a
regional registration.
A regional registration establishes a regional care-of-address
that is seen from outside the visited domain as the mobile node's
primary care-of-address. This address is contolled by one of the
visited-domain routers and the mobile node obtains the address from a
list of Regional CoA extensions (Section 4.2), attached to the router
advertisement.
After obtaining a regional care-of-address, the mobile node stores
the current visited domain identity, and sends binding updates to
its home agent and corresponding nodes. The mobile node uses the
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________
+------------+ / \ +--------------------+
| Home Agent |------( Internet )----| Corresponding node |
+------------+ \________/ +--------------------+
|
| regional \
| care-of-address +
+------------------------+ |
| Gateway Mobility Agent | |
| (GMA) | |
+------------------------+ |
/ \ |
1./ \ |
/ \ |
+------------------+ +--------+ |
| Crossover Router | | Router | |
+------------------+ +--------+ |
/ \ | Visited
1./ \ 2. |o Domain
/ \ |
+----------+ +--------+ |
| Previous | | New | |
| Access | | Access | |
| Router | | Router | |
+----------+ +--------+ |
^ ^ |
|1. |2. |
| | |
+-+ +-+ (on-link) primary |
| | ---> | | care-of-address |
+-+ +-+ +
Mobile Mobile /
Node Node
Figure 1: Hierarchy of regional-aware routers
regional care-of-address as the alternate care-of-address when
sending basic Mobile IPv6 binding updates to nodes outside the
visited domain.
While staying within the visited domain, the mobile node MAY send
regional binding updates for the duration of its home binding. The
mobile node may also send ordinary binding updates to the home agent
or to corresponding nodes at any time.
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Figure 1 illustrates a typical regional registration scenario. The
mobile node sends a regional binding update to the crossover router
which updates its connection state from the old path to the new path.
The gateway router is the crossover router during the first regional
registration (signal 1). After this (signal 2), the crossover may
exist lower in the hierarchy.
The regional binding update is a modified Binding Update destination
option. It updates the regional binding cache entries of a mobile
node in regional-aware router hierarchy. The binding update also
enables the visited domain to decide the crossover router. The
mobile node attaches additional information to this binding update
such that a regional-aware router can decide from it whether it is a
crossover router.
The regional binding cache is used for regional data routing,
forwarding of encapsulated or route-optimised Mobile IPv6 data
packets to the mobile node. The binding cache entries are deleted by
timeout or by de-registration. The semantics of this is identical to
that in basic Mobile IPv6.
3.1. Movement to a new Link
When entering a new foreign link , with the same or another visted
domain, the mobile node performs movement detection and uses router
discovery to discover new routers as defined in Mobile IPv6. The
mobile node may also receive a handoff indication from the link layer
and consequently send a router solicitation.
The mobile node also performs visited domain detection as an
additional part of the movement detection of basic Mobile IPv6. The
mobile node uses the visited domain identity field of the router
advertisement's prefix information option (Section 4.1) to detect
movement to a new visited domain. This identity MUST be unique. A
recommended way to generate it is to take a suitable (TBD) 32-bit
hash from the realm part of the access router's network access
identifier [1].
When the mobile node changes its regional care-of-address, or
when the selected regional care-of-address is not in the router
advertisement of the new access router, the mobile node SHOULD behave
as if it arrived to a new visited domain. This avoids the situation
where the crossover router would be beyond the GMA in the hierarchy.
The mobile node then selects its primary care-of-address, which
is on the same link as is the access router, as defined in Mobile
IPv6. The address is co-located to the mobile node together with its
routing identity, its home address, and used as the target for local
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communication between the visited domain and the mobile node. The
mobile node MAY also use this address as the care-of-address in its
binding updates for corresponding nodes within the visited domain.
3.2. Visited-domain capability discovery
The router advertisement from a regional-aware router contains flags
to indicate the supported capabilities. The supported capability
flag for regional registrations is the `I' bit in the Reserved1 field
of the Mobile IPv6 Modified Router Advertisement Message's Modified
Prefix Information Option [4].
If the `I' bit is set, the mobile node SHOULD make use of regional
registration. In this case, the mobile node selects its regional
care-of-address from the one or more regional care-of-address
extensions in the router advertisement.
3.3. Regional Registrations signaling
When entering the visited domain, the mobile node performs an home
registration in combination with the first regional binding update.
The regional binding update is a modified Mobile IPv6 binding update
destination option. It propagates upwards hop-by-hop through a
hierarchy of regional-aware routers to a router controlling the
selected regional care-of-address. There may be regional-unaware
routers between adjacent regional-aware routers in a hierarchy.
The regional care-of-address can be an address of the visited domain
router or an address from a pool of regional care-of-addresses
controlled by a router. Association between such a care-of-address
and a router within the visited domain, selected as target of the
first regional binding update, is implementation-specific.
The destination address in the IP header of the regional binding
update at the sending mobile node is the source address of the router
advertisement containing the selected regional care-of-address.
There MUST be a home address detination option in the IPv6 packet
carrying the regional binding update as with basic Mobile IPv6.
When the regional binding update is re-sent from the receiving router
up to the next higher router, each regional-aware router establishes
or updates its regional binding cache entry for the mobile node.
The key to the entry is the home address, and the care-of-address
is the source address of the regional binding update received from
the next lower regional-aware router. In the access router, the
care-of-address is the sending link address of the mobile node.
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Implementation of the regional binding cache can reuse the basic
Mobile IPv6 binding cache entry with a new `I' flag set.
Since the network controls the crossover router selection, the
visited domain target router is not known to the mobile node. Thus,
it then sends the packet to the router from which the advertisement
was received. The regional care-of-address MUST be inserted as a
alternate care-of-address sub-option of the regional binding update.
The `A' bit MUST be set and the `H' bit MUST NOT be set.
The mobile node appends the previous access router
sub-option (Section 4.4) to the regional binding update. This
sub-option identifies the previous access router so that each router
can locally decide whether it is the crossover router. When the
signal is propagated upwards, the first router that has the previous
access router among its descendants is the crossover router. To know
its descendants, a regional-aware router maintains a list of all of
its descendants. How this list is configured is out of the scope of
this protocol, it can be statically configured from a parameter file,
for example.
After a successful regional binding update, a basic Mobile IPv6
binding acknowledgement is returned to the mobile node. A succesful
regional registration is denoted by a new success status value
1. This denotes regional-aware success, status value 0 denotes
regional-unaware success. In the latter case, the receiving node
accepted the binding update as any corresponding node would. The
mobile node can thus send regional binding updates to any node and
recognize regional-awareness of the other end from this status
value. This gives the protocol robustness against mis-configured
regional-aware routers.
The mobile node SHOULD NOT send binding updates with the regional
care-of-address to regular nodes until it has received the
regional-aware success status value 1. If the regional-aware router
fails to accept the regional registration, it returns a Reason
Unspecified status value 128 in the binding acknowledgement. If the
access control policies allow, the regional and non-regional binding
updates MAY be transmitted in parallel. However, if the mobile node
does not receive status value 1 from the gateway mobility agent, the
mobile node MUST re-send the non-regional binding updates with the
primary care-of-address.
A regional-aware mobile node MAY support mobile multi-homing,
i.e. the mobile node MAY register more than one home address
simultaneously with one or more home agents. Operation of these
addresses occur independently, i.e. as if there were multiple mobile
nodes within the same physical host. The mobile node MUST NOT
register more than one care-of-address for each home address.
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3.4. Regional-Aware Data Routing
Regional data routing considers routing towards the mobile node.
Since the regional care-of-address is in the visited domain, packets
targeted to it go through the regional-aware routing hierarchy from
the GMA to the mobile node. The other direction is not affected by
regional registrations.
3.4.1. Regional Forwarding of Encapsulated Packets
When a corresponding node sends data packets to a mobile node to
which it does not yet have an entry in its binding cache, these
packets are intercepted by the home agent and encapsulated to
the registered care-of-address mobile node, as specified in the
basic Mobile IPv6. However, this care-of-address is the alternate
care-of-address.
In the case with tunneled packets, the regional care-of-address of
the mobile node is selected as the target for the outer encapsulation
header. The router which controls that regional care-of-address
decapsulates the tunneled packets. The destination of the
encapsulated packet is the home address of the mobile node.
If there is an entry in the regional binding cache for this home
address, the router MUST re-encapsulate these packets to the
corresponding lower care-of-address. This is in the next lower
regional-aware router or in the mobile node if the forwarder is the
access router. Thus, the data packets get re-capsulated at each
regional-aware router on their way down the hierarchy.
3.4.2. Regional Forwarding of Route-Optimised Packets
When a corresponding node has received a binding update, it knows
the regional care-of-address and sends packets to the mobile node
using this address as the destination address. The corresponding
node includes a type 0 routing header to the packet so that the home
address of the mobile node is the only entry in the routing header of
this route-optimised packet, as specified in the basic Mobile IPv6.
A regional-aware router forwards a route-optimised packet to the next
lower regional-aware router in a special way. If there is an entry
in the regional binding cache for the home address in the routing
header, the routing header is kept in its original state. That
is, the home address remains in the routing header entry, and the
`segments left' field is not decreased.
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The packet is then forwarded ahead using the regional binding cache
entry. The destination address of the route-optimised packet is
replaced with the care-of-address in the regional binding cache and
the packet is then submitted back to the IP forwarding engine for
further processing. If no regional binding cache entry exists for
the given home address, standard IPv6 routing processing applies.
When the mobile node receives the packet that has been forwarded
using regional-aware data routing, packets have the encapsulation or
routing header so that the MN can still distinguish whether to send
a binding update to a corresponding node, as in basic Mobile IPv6.
The authentication header integrity check calculation is also still
identical to what would be needed in a basic Mobile IP mobile node.
When the mobile node sends packets to a corresponding node, the
source address is the primary care-of-address of the mobile node,
and the destination address is the corresponding node. The packets
contain the home address extension as with the basic Mobile IPv6.
Thus, their routing towards the corresponding node occurs exactly as
with the basic Mobile IPv6.
4. Protocol Extensions
The following protocol extensions are defined:
- A modification to the Modified Router Advertisement Message
to indicate whether the visited domain supports regional
registrations (the `I' bit) (Section 4.1).
- A visited-domain identifier in the router
advertisement (Section 4.1).
- A regional care-of-address extension to the router
advertisement (Section 4.2).
- A modification to the Binding Update destination option to
indicate whether the option is a Regional Binding Update (the `I'
bit) (Section 4.3).
- An previous access router sub-option for the binding
update (Section 4.4).
4.1. Router Advertisement modifications
The router advertisement, as defined in the basic Mobile IPv6,
contains additionally the `I' bit and the visited domain identity in
the Modified Prefix Information Option of the Router Advertisement
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Message. The format of the new Modified Prefix Information Option is
the following:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Prefix Length |L|A|R|I|Rsrvd1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Valid Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preferred Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Visited-Domain Identity |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Prefix +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: The Modified Prefix Information Option
I Indicates regional registrations support.
Visited-Domain Identity
This identity is a unique unsigned 32-bit integer. A
recommended way to generate it is to take a suitable
32-bit (TBD) hash from the realm part of the access
router's network access identifier [1].
The Rsvrd1 field is here a 4-bit field instead of the 5 bits
Reserved1 prior to adding the `I' bit. Other fields are as described
in the Mobile IPv6 and the Neighbor Discovery [8] documents.
4.2. Regional CoA Extension
The router advertisement may contain one or more visited-domain
care-of-addresses from which the mobile node chooses a regional
care-of-address. Each such address is advertised in a Regional CoA
Extension of the modified Router Advertisement.
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The format of the regional CoA extension is the following :
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length=2 | Preference | Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Regional Care-of-Address |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Regional CoA extension
Type TBD (skippable)
Length 8-bit unsigned integer. The length of the option
(including the type and length fields) in units of 8
octets. This field MUST be 2.
Lifetime The time the advertised CoA is valid in the visited
domain.
Preference A preference for the CoA. An 8 bit unsigned integer. A
value of 255 means lowest preference.
Index Index describing which of the global prefixes can be
used with this address. 1 denotes the first prefix in
the advertisement. Special value 0 denotes that this
address applies to all prefixes. The options SHOULD be
ordered so that regional CoA extensions associated with
a given prefix are immediately after that prefix.
Regional Care-of-Address
The advertised address, which MUST be a global IPv6
address from the visited domain.
4.3. Regional Binding Update
The Regional Binding Update is a Mobile IP Binding Update with the
following modifications. In the Reserved field after the flags
field, there will be the following additional bit.
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Description of extensions to the BU option:
I Indicates regional registrations support. This implies
that the receiving router will use the BU information to
establish or maintain a regional binding cache entry. The
bit is the first bit from the Reserved field of the Mobile
IPv6 Binding Update destination option.
Previous Access Router Sub-Option
A sub-option for determining the crossover router.
4.4. Previous Access Router Sub-Option
The previous access router sub-option is used by the network
to determine the crossover router. A crossover router address
is obtained from the IP header source address of the router
advertisement. The mobile node remembers this for the previous
router and uses it to create an previous access router sub-option.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Previous access router |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Previous Access Router Sub-option
Type TBD (skippable)
Length 8-bit unsigned integer. The length of the sub-option
(including the type and length fields) in units of 8
octets.
Previous access router
The IP address of the previous access router as seen
by the mobile node.
There is no requirement for alignment of the Previous Access Router
sub-option.
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The previous access router sub-option is valid in the Binding Update
destination option. The previous access router contains the IPv6
address of the access router as seen by the mobile node. It is used
to identify the crossover router in the visited domain regional
router graph. This is done by comparing the previous access router
to the known descendants when the regional binding update gets
forwarded upward in the tree of regional-aware routers. When the
router finds the previous access router in its list of descendants,
it is the crossover router.
5. New requirements for IPv6 Nodes
The presented option requires modifications to the visited-domain
routers and to the mobile node. The option does not pose new
requirements, in particular, to the home agent, to corresponding
nodes, or to other network elements than to the regional-aware
routers in the visited domain.
5.1. Visited Domain Router Requirements
The support of the protocol is optional to basic Mobile IPv6;
elements can function in both regional-aware and regional-unaware
visted domains. Introducing regional-aware routers to a visited
domain does not mandate the use of regional registrations.
The regional-aware access router MUST be capable of advertising
regional registration support. The router MUST be capable of
maintaining regional binding cache entries based on regional
binding updates. These routers MUST route the data packets to the
regional-registered mobile nodes so that a mobile node can recognize
the use of route optimization from the presence of a routing header,
as described in Section 3.4.
5.2. Mobile Node Requirements
A regional non-aware mobile node can operate in a regional-aware
network. A regional-aware mobile node MUST recognize the use
of regional registrations from the router advertisement. The
regional-aware mobile node MUST be able to select a regional
care-of-address and send a regional binding update accordingly.
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6. IANA Considerations
The presented protocol does require the addition of one skippable
option type to the router advertisement [8] and one skippable
sub-option type to the Binding Update destination option.
Also, the protocol requires two modifications from the Modified
Router Advertisement Message`s Prefix Information Option, one bit in
its Reserved1 field, and the Reserved2 field completely, from the
format specified in the basic Mobile IPv6 [4]. The protocol also
needs one new bit from the Reserved field of the Mobile IPv6 Binding
Update option.
The Binding Acknowledgement would need one new regional-aware success
code, with a proposed value of 1 to be added to the list of known
status field values.
7. Security Considerations
The regional-aware mobile node SHOULD use a mobile-visited-domain key
for authentication. IPsec and its authentication header is used for
security as in basic Mobile IPv6. In regional signaling, the mobile
node and visited domain share a dynamic security association, in form
of a mobile-visited-domain key for IPsec. The mobile-visited-domain
key is obtained when entering the visited domain and transported
to the visted domain routers and to the mobile node. Details of
security, such as regional authorization, key distribution, and
replay protection are out of the scope of this document.
8. Acknowledgements
We would like to thank people who have participated in reviewing this
document, including Hannu Flinck, Robert Chalmers, Rajeev Koodli,
Govind Krishnamurthi, and Dan Forsberg.
References
[1] B. Aboba and M. Beadles. The Network Access Identifier. Request
for Comments (Proposed Standard) 2486, Internet Engineering Task
Force, January 1999.
[2] S. Bradner. Key words for use in RFCs to Indicate Requirement
Levels. Request for Comments (Best Current Practice) 2119,
Internet Engineering Task Force, March 1997.
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[3] Eva Gustafsson, A. Jonsson, and C. Perkins. Mobile IP Regional
Registration (work in progress).
draft-ietf-mobileip-regtun-02.txt, June 2000.
[4] D. Johnson and C. Perkins. Mobility Support in IPv6 (work in
progress). Internet Draft, Internet Engineering Task Force,
November 1998.
[5] R. Koodli and C. Perkins. A Framework for Smooth Hand-overs in
IP Mobile Networks (work in progress).
draft-ietf-koodli-smoothv6-00.txt, July 2000.
[6] Rajeev Koodli, Manish Tiwari, and C. Perkins. Header Compression
State Relocation in IP Mobile Networks (work in progress).
draft-koodli-rohc-hc-relocate-00.txt, July 2000.
[7] Govind Krishnamurthi, Robert C. Chalmers, and C. Perkins.
Buffer Management for Smooth HandOvers in Mobile IPv6 (work in
progress).
draft-krishnamurthi-mobileip-buffer6-00.txt, July 2000.
[8] T. Narten, E. Nordmark, and W. Simpson. Neighbor Discovery for
IP Version 6 (IPv6). Request for Comments (Draft Standard) 2461,
Internet Engineering Task Force, December 1998.
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Addresses
The working group can be contacted via the current chairs:
Basavaraj Patil Phil Roberts
Nokia Corporation Motorola
6000 Connection Drive 1501 West Shure Drive
M/S M8-540
Irving, Texas 75039 Arlington Heights, IL 60004
USA USA
Phone: +1 972-894-6709 Phone: +1 847-632-3148
Fax : +1 972-894-5349
EMail: Basavaraj.Patil@nokia.com EMail: QA3445@email.mot.com
Questions about this memo can also be directed to the authors:
Jari T. Malinen Charles E. Perkins
Communications Systems Lab Communications Systems Lab
Nokia Research Center Nokia Research Center
Itamerenkatu 11-13 313 Fairchild Drive
FIN-00180 Helsinki Mountain View, California 94043
Finland USA
Phone: +358 40 4799 138 Phone: +1-650 625-2986
EMail: jari.t.malinen@nokia.com EMail: charliep@iprg.nokia.com
Fax: +358 9 4376 6852 Fax: +1 650 625-2502
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