Subject: [MEXT] NEXTEXT2 BOF

From: "Victor Blake" <[email-masked]>
Date: Fri, 3 Jul 2009 13:35:25 -0400

To the Chair and authors of the NEXTEXT2 BOF in particular,

I am pleased to see the consideration of the challenges of multi-layer
mobility being considered here. I support the idea of considering, as the
draft authors suggest below, 

Layer 2 mobility models (independent of L3 methods)
- Because these could support models with either network based global
mobility (such as PMIP) or client based mobility (CMIP) or independent local
mobility without the "L3 methods." Although the latter might apparently seem
to indicate no need to improvements in IETF, this is not necessarily the
case. This is because there could be (I believe there is) demand for layered
approaches to mobility wherein a service provider or entity might want to
layer mobility on top of mobility. Although such methods could be made to
work off the shelf, the demand for fast mobility (such as FMIP) could be
difficult to accomplish without cross-layer signaling.

Hybrid Layer 2/3
- I'm not sure how this differs from the above. If we assume an independent
L2 model (CAPWAP, LWAP, L2TP, etc.) L3 would, by definition -- not "know"
about the underlying L2 mobility. Is hybrid to mean that the layers MUST of
necessity know to work together or CHOULD/SHOULD know. This might be the
same as what I describe above. My only comment is that I think it is helpful
to both support independent L2 from L3, but also allow cross-layer signaling
to assist or expedite event handling

Layer 3 (independent of L2 technologies)
- Still quite valuable when being applied across multiple ran/wireline
technologies
- As the above comments suggest, even where there is "apparently" L3
independent, there could be underlying L2 mobility not visible to the L3
elements

I think that that (additional) issues to consider are:
1. Bootstrap procedure for identifying or assisting with multi-layer
signaling and multi-layer mobility
2. Multi-attached (multi-homed) devices
3. concurrent mobility
4. Layered (hybrid) approaches -- operator control (enable/disable)
multi-layer signaling
5. Integration with network (versus device) mobility -- perhaps segregated
by layers (this might be out of scope for this work)

Victor Blake
[email-masked]

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Message: 1
Date: Sun, 28 Jun 2009 20:16:11 +0200
From: marcelo bagnulo braun <[email-masked]>
Subject: [MEXT] NEXTEXT2: first draft of the bof description
To: [email-masked], mext <[email-masked]>, [email-masked]
Cc: "Soininen Jonne \(NSN FI/Espoo\)" <[email-masked]>, Jari
    Arkko <[email-masked]>, [email-masked]
Message-ID: <[email-masked]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi,

This is a first draft of the BOF description for your consideration. It 
is still very open so, feel free to comment on whether the proposed 
approach seems appropriate or not.

NETEXT2 BOF description
-----------------------

Proxy Mobile IPv6 (PMIP6) [RFC5213] is a network based mobility
protocol built on Mobile IPv6 [RFC3775]. PMIP6 provides mobility to
IP hosts without requiring any protocol enhancements or additional
capabilities on the host.
Current PMIP6 specification fully defines how to provide mobility
support for mobile nodes with a single interface roaming in a PMIP6
domain. The goal of this BOF is gain understanding of how to support
nodes with multiple interfaces (of possible different technologies) in a
PMIP6 network.

In particular, this BOF assumes the following scenario:
We have a single PMIP6 domain that has deployed multiple
access technologies and needs to support nodes that have
multiple interfaces, possibly of different technologies.

In particular, the following capabilities are needed:

- Inter-technology handover support. The MN has initiated a
communication over one interface and it needs to be able to move
the established connection to a different interface of
a possibly different technology. The reason for moving
the communication to another interface is because of the MNs
mobility and attaching via a different interface. Basically
the ability to perform handovers that span different access
technologies.

- Multihoming support. The MN with multiple interfaces of possibly
different technologies should be able to use them simultaneously to
exchange data and manage the mobility of communications
established through the different interfaces.

- Flow mobility. A MN with multiple interfaces of possibly
different technologies must be able to move a flow from
one interface to another. Moreover, the MN should be able
to inform the network through which interface it wishes
to receive different types of flows.

In order to provide the support for these capabilities, different
approaches can be envisioned, namely:
- L2 only approaches. In this type of approaches, the mechanisms
to provide the required capabilities are fully L2 mechanisms and
no modification of the IP layer is needed.
- L3 only approaches. In this type of approaches, the mechanism to
provide to required capabilities are located in the IP layer
- Hybrid L2/L3 approaches. In this case, some mechanisms are
located in L2 and other mechanisms are located in L3.
Now, the different possible approaches vary greatly in their nature
and resulting capabilities. To understanding the benefits and
suitability of these alternatives, the requirements have to be
properly defined and understood.

The main goal of the BOF is understanding the need for work in the
IETF in this area. In order to do so, during the BOF, we will attempt to:

1) Understand the applicable scenarios, and the problem statement related to
those
2) Understand the restrictions and requirement imposed to solutions to
address the problem statement and scenarios
3) Get an overview of the proposed solutions

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