Subject: [mobile-ip] Regional abstracts

From: "Alan O'Neill" <[email-masked]>
Date: Wed, 8 May 2002 22:17:53 -0400

Abstract as promised,  Alan.

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Abstract (Nested)

   Regional Registration provides a mechanism for MIPv4 to localise 
   registrations. The Mobile Node (MN) initially registers to the HA via the

   Gateway Foreign Agent (GFA) so that the HA can learn the GFA Care of
Address 
   (CoA). The MN can then subsequently use a Regional Registration to
maintain 
   the binding in the GFA as the MN moves and changes its Foreign Agent (FA)
CoA 
   or Collocated CoA (CCoA). It can continue to do so whilst a MN remains
under 
   the GFA through which the MN sent the Home Registration. The GFA performs
CoA 
   switching between the GFA CoA and that used by the MN (CCoA or FA CoA).

   Whilst the regional registration provides localisation, it does not at
the 
   same time provide registration aggregation for MNs employing multiple
HoAs. 
   The ability to concurrently support multiple MN addresses from arbitrary 
   addressing domains is a 3GPP commercial and technical requirement and 
   therefore of interest to operators seeking to move to an all-IP solution 
   based on MIP. In addition, the GFA is a very stateful element in the core
of  
   the Internet that cannot be bypassed on failure through routing updates.

   This draft describes a complementary, less stateful model for
localisation 
   that in addition supports aggregation both for regional-like registration
and 
   hand-offs. The model re-uses as much as possible from the home
registration 
   signalling model of [RegTun] but requires a new form of aggregated
regional 
   registration.

-----------------------------------------------------------

Abstract (Parallel)

   Nested MIP [NestMIP] provides a means to support both localization and 
   aggregation of MIP signalling. It achieves this by providing two distinct

   layers of MIP signalling and forwarding; a local access layer that
provides 
   local mobility management and local access services, and a remote access 
   layer that provides remote access back to a home subnet. Nested MIP and
an 
   associated proposal, Concatenated MIP [ConcatMIP] are necessary because 
   existing MIP signalling is HA/HoA specific and therefore not easily
amenable 
   to aggregation for supporting multiple MIP sessions per MN. 

   This document describes an alternative proposal for introducing
aggregation 
   that has significantly lower functionality but that is a smaller change
from 
   existing MIP standards and implementations. It is described here for 
   completeness as part of the overall problem space. The solution uses a
single 
   HA/HoA specific MIP Registration as a master signal within which is
carried 
   an extension that defines  an include/exclude list of the other HA/HoA
pairs 
   that should/should not be handed off. This extension can be carried in
inter-
   FA hand-off signals and in regional registrations, and is also used
within 
   Nested/Concat MIP.

------------------------------------------------------------

Abstract (Concat)

   Nested MIP [NestMIP] provides a means to support both localization and 
   aggregation of MIP signalling. It achieves this by providing two distinct

   layers of MIP signalling and forwarding; a local access layer that
provides 
   local mobility management and local access services, and a remote access 
   layer that provides remote access back to a home subnet. The local access

   layer provides a regional address from a Regional Mobility Agent (a
regional 
   HA) that is then used as a CCoA for the remote access layer. Inter-FA 
   movement and MIP signalling at the local access layer then automatically 
   produces the hand-off of potentially multiple parallel remote access 
   sessions. The consequences of this model are however reductions in
bandwidth 
   efficiency due to the additional layers of temporary and permanent 
   encapsulation.

   This draft describes a complementary model for MIP forwarding, called 
   Concatenated MIP that re-uses, and extends the localised and aggregated
MIP 
   signalling model from [NestMIP]. The enhanced forwarding model is
intended to 
   co-exist both with [NestMIP] and [RegTunMods] so that the appropriate
trade-
   offs can be made on a per session basis between bandwidth efficiency and 
   other features. Inter-RMA hand-offs between Nesting and Concatenating 
   Regional Mobility Agents is also supported.

-------------------------------------------------------------

Abstract (RMAsig)

   Nested MIP [NestMIP] and Concatenated MIP [ConcatMIP] provide means to 
   support both localization and aggregation of MIP signalling. They achieve

   this by providing two distinct layers of MIP signalling and forwarding; a

   local access layer that provides local mobility management and local
access 
   services, and a remote access layer that provides remote access back to a

   home subnet. The local access layer provides a regional address from a 
   Regional Mobility Agent (a regional HA) that is then used as a CCoA for
the 
   remote access layer. Inter-FA movement and MIP signalling at the local
access 
   layer then automatically supports the hand-off of potentially multiple 
   parallel remote access sessions. Nested MIP achieves this through 
   encapsulation whilst Concatenated MIP achieves it though various forms of
CoA 
   switching.

   This draft describes the localised and aggregated MIP signalling model
for 
   managing both the Local Access and Remote Access MIP layers. This
includes 
   inter-FA and Inter-RMA hand-offs within and between Nesting and
Concatenating 
   Regional Mobility Agents. This is necessary to support incremental, 
   heterogeneous deployment that is required given that Nested MIP is
deployable 
   now whilst Concatenated MIP requires additional and significant standards
and 
   development work.

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Abstract (PCCoA)

In MIPv4, when a Mobile Node (MN) registers with the 'D' bit, in the MIP
Registration to a Home Agent (HA), then the MN wishes to use a Co-located
Care-of address (CCoA) with a specific Home Address (HoA). Packets sent to
the MN Home Address (HoA) will then be encapsulated in the CCoA by the HA
and forwarded directly to the MN. Alternatively, a MN can obtain from the
local Foreign Agent(FA) a shared FA CoA for inclusion in its MIP
Registration to the FA/HA. In this case, the HA encapsulates to the FA CoA,
and the Foreign Agent then decapsulates and delivers the HoA addressed
packet unencapsulated to the MN. This draft adds to MIPv4 the ability for
the MN to acquire a MN specific FA CoA that provides the MN with a
topologically correct local address and whose tunnel encaps/decaps is
provided by the FA. This address is called a proxy CCoA (PCCoA) and the
associated processing in the MN and FA is called Proxy CCoA tunneling. This
capability is applicable to any access technology but is especially useful
for wireless systems where the access bandwidth is expensive and when
point-to-point link-layer connectivity exists between the MN and the FA.
This draft also describes reverse tunneling and smooth hand-off extensions
based on the PCCoA that enables inter-FA forwarding even for CCoAs.