Subject: [mobile-ip] Regional MIP Drafts from Flarion

From: "Alan O'Neill" <[email-masked]>
Date: Wed, 8 May 2002 22:13:16 -0400

Folks, 

I have submitted the following drafts as mentioned last week that relate to
the regional tunneling issues that we have been discussing. I guess they
won't be availabe for a couple of days yet so I will send out a link to the
drafts on the Flarion web-site (www.flarion.com) as soon as they are
available there.

Nested MIP for Mobility Management
<http://www.ietf.org/internet-drafts/draft-oneill-mip-nested-00.txt>
Parallel MIP for Mobility Management
<http://www.ietf.org/internet-drafts/draft-oneill-mip-concat-00.txt>
Concatenated MIP for Mobility Management
<http://www.ietf.org/internet-drafts/draft-oneill-mip-parallel-00.txt>
Regional Mobility Agent Signalling
<http://www.ietf.org/internet-drafts/draft-oneill-mip-RMA-sig-00.txt>
Proxy CCoA Tunneling for Mobile IP
<http://www.ietf.org/internet-drafts/draft-oneill-mip-PCCoA-00.txt>

For those interested I have enclosed the abstracts in a separate e-mail but
an overall summary is below. The recommended reading order is as shown
above.

The drafts aim to address a requirement that appears to be unaddressed by
existing specs. Regional tunneling provides localisation of signalling but
it does not provide aggregation of signalling when a MN has multiple HoAs.
MIP signalling is presently HA/HoA specific and hence multiple HoAs leads to
'Parallel MIP' hand-off signalling (issues covered in Parallel draft) to the
HA and the oFA, and also to any intermediate regional element. Multiple HoAs
are required for concurrent local and remote access sessions, and also for
third party content/application service provider networks. The architecture
also aims to cleanly separate out the different operator control
requirements for local and remote access traffic.

Nested and Concatenated MIP are two alternative ways to address this
requirement, both of which also address localisation (note that GFA type
forwarding can also be supported with some constraints). They both use two
layers of MIP signaling, the Local Access layer and the Remote Access layer
to decouple intra operator from inter-operator concern. Nested MIP using
encapsulation between the layers whilst Concatenated using switching between
the two layers to address the requirements. The LA layer runs between the
MN, FA and a Regional Mobility Agent that can be thought of as a local HA
for now. The RMA allocates a Regional address (RoA)to the MN which it can
use as a valid interface address for local access within the region of the
RMA. The RoA is also used as the CCoA for a potential multitude of remote
access MIP sessions in the RA layer (and can also be used for IPSRA or PPTP
sessions). This then enables an MIP hand-off at the LA to also move all RA
layer sessions at the same time. The RoA is valid within a region and
therefore localisation is achieved for hand-offs within that region, until
the RoA has to change. The clean separation of the two layers (local and
remote) brings a wide range of benefits but there are of course costs as
mentioned in the documents. For example, on the plus side, packets to the
RoA are routed through the RMA rather than as a result of switching state
and therefore the RMA regional element is more amenable to routing based
recovery. On the downside, packets are encapsulated over the air-interface
due to the use by the MN of a CCoA at the RA layer. This is addressed in a
generic way for CCoAs by adding an MIP address mode called Proxy CCoAs where
the tunnel management for the CCoA is left to the FA. 

Basic Nested MIP can be deployed with very little impact on existing MIP
standards -  a critical characteristic for Flarion. Enhanced features
require signalling enhancements, and specifically we want to share the 'I'
bit and HFAext/HFAIPext mechs from [RegTun],[RegTunmods] as the RMA can also
support GFA and the mechanisms for the different forwarding modes are very
similar. Concatenated mode and GFA mode are only available if the home
registration is routed via the RMA.

The RMA signalling draft is a very long document which overviews the
detailed signalling mechanisms required to support Nested, Concat and GFA
modes in an RMA through a number of evolution steps that support RMA
hand-off between the modes. I think all required changes are fully backwards
compatible although don't quote me yet. This draft also adds a number of
features to the integrated model. There are many issues yet to be solved and
I hope that if the wg appreciates the solution that a work programme can be
defined. This will definitely require significant draft rewrites to break
the work into manageable evolutionary chunks.

When comparing RMA to the GFA from Reg Tun, the key differences are that the
regional reg in GFA happens after the home reg whilst the opposite is true
for RMA, the GFA is less amenable to routing based recovery, the GFA does
not support signalling aggregation and the GFA has some additional issues
with private / public address support. The GFA is however very efficient for
a single RA or LA session per MN and the forwarding rules are obviously less
complex under these conditions.

As a final point I would recommend people take a bit of time to read and
digest these docs before bringing detailed discussions to the list. There is
a lot of information and the complete cost/benefit story takes a fair amount
of processing.

Regards, Alan O'Neill
Flarion Technologies.

---

From: Phil Roberts <[email-masked]>
Date: Thu, 9 May 2002 09:26:39 -0400

I haven't read any of these yet, Alan.  Could you let us know whether
you see these as additions to the regional registration draft or
replacements?
When you tentatively assert backwards compatibility is that with regional
registrations or with RFC 3220 or both?

Thanks,
Phil

> -----Original Message-----
> From: Alan O'Neill [mailto:[email-masked]] 
> Sent: Wednesday, May 08, 2002 10:13 PM
> To: [email-masked]
> Subject: [mobile-ip] Regional MIP Drafts from Flarion
> 
> 
> Folks, 
> 
> I have submitted the following drafts as mentioned last week 
> that relate to the regional tunneling issues that we have 
> been discussing. I guess they won't be availabe for a couple 
> of days yet so I will send out a link to the drafts on the 
> Flarion web-site (www.flarion.com) as soon as they are 
> available there.
> 
> For those interested I have enclosed the abstracts in a 
> separate e-mail but an overall summary is below. The 
> recommended reading order is as shown above.
> 
> The drafts aim to address a requirement that appears to be 
> unaddressed by existing specs. Regional tunneling provides 
> localisation of signalling but it does not provide 
> aggregation of signalling when a MN has multiple HoAs. MIP 
> signalling is presently HA/HoA specific and hence multiple 
> HoAs leads to 'Parallel MIP' hand-off signalling (issues 
> covered in Parallel draft) to the HA and the oFA, and also to 
> any intermediate regional element. Multiple HoAs are required 
> for concurrent local and remote access sessions, and also for 
> third party content/application service provider networks. 
> The architecture also aims to cleanly separate out the 
> different operator control requirements for local and remote 
> access traffic.
> 
> Nested and Concatenated MIP are two alternative ways to 
> address this requirement, both of which also address 
> localisation (note that GFA type forwarding can also be 
> supported with some constraints). They both use two layers of 
> MIP signaling, the Local Access layer and the Remote Access 
> layer to decouple intra operator from inter-operator concern. 
> Nested MIP using encapsulation between the layers whilst 
> Concatenated using switching between the two layers to 
> address the requirements. The LA layer runs between the MN, 
> FA and a Regional Mobility Agent that can be thought of as a 
> local HA for now. The RMA allocates a Regional address 
> (RoA)to the MN which it can use as a valid interface address 
> for local access within the region of the RMA. The RoA is 
> also used as the CCoA for a potential multitude of remote 
> access MIP sessions in the RA layer (and can also be used for 
> IPSRA or PPTP sessions). This then enables an MIP hand-off at 
> the LA to also move all RA layer sessions at the same time. 
> The RoA is valid within a region and therefore localisation 
> is achieved for hand-offs within that region, until the RoA 
> has to change. The clean separation of the two layers (local and
> remote) brings a wide range of benefits but there are of 
> course costs as mentioned in the documents. For example, on 
> the plus side, packets to the RoA are routed through the RMA 
> rather than as a result of switching state and therefore the 
> RMA regional element is more amenable to routing based 
> recovery. On the downside, packets are encapsulated over the 
> air-interface due to the use by the MN of a CCoA at the RA 
> layer. This is addressed in a generic way for CCoAs by adding 
> an MIP address mode called Proxy CCoAs where the tunnel 
> management for the CCoA is left to the FA. 
> 
> Basic Nested MIP can be deployed with very little impact on 
> existing MIP standards -  a critical characteristic for 
> Flarion. Enhanced features require signalling enhancements, 
> and specifically we want to share the 'I' bit and 
> HFAext/HFAIPext mechs from [RegTun],[RegTunmods] as the RMA 
> can also support GFA and the mechanisms for the different 
> forwarding modes are very similar. Concatenated mode and GFA 
> mode are only available if the home registration is routed 
> via the RMA.
> 
> The RMA signalling draft is a very long document which 
> overviews the detailed signalling mechanisms required to 
> support Nested, Concat and GFA modes in an RMA through a 
> number of evolution steps that support RMA hand-off between 
> the modes. I think all required changes are fully backwards 
> compatible although don't quote me yet. This draft also adds 
> a number of features to the integrated model. There are many 
> issues yet to be solved and I hope that if the wg appreciates 
> the solution that a work programme can be defined. This will 
> definitely require significant draft rewrites to break the 
> work into manageable evolutionary chunks.
> 
> When comparing RMA to the GFA from Reg Tun, the key 
> differences are that the regional reg in GFA happens after 
> the home reg whilst the opposite is true for RMA, the GFA is 
> less amenable to routing based recovery, the GFA does not 
> support signalling aggregation and the GFA has some 
> additional issues with private / public address support. The 
> GFA is however very efficient for a single RA or LA session 
> per MN and the forwarding rules are obviously less complex 
> under these conditions.
> 
> As a final point I would recommend people take a bit of time 
> to read and digest these docs before bringing detailed 
> discussions to the list. There is a lot of information and 
> the complete cost/benefit story takes a fair amount of processing.
> 
> Regards, Alan O'Neill
> Flarion Technologies.
>

---

From: "Alan O'Neill" <[email-masked]>
Date: Thu, 9 May 2002 22:40:42 -0400

It is both although the documents cover a range of evolution steps and
options in which specific decisions could render loss of backwards
compatibility wrt RegTun but this would only be when specifically intended
to do so (ie if GFA is not deployed)..

-----Original Message-----
From: Phil Roberts [mailto:[email-masked]]
Sent: 09 May 2002 22:57
To: [email-masked]
Subject: RE: [mobile-ip] Regional MIP Drafts from Flarion

Thanks,
Phil