2.3.17 Network Mobility (nemo)

NOTE: This charter is a snapshot of the 64th IETF Meeting in Vancouver, British Columbia Canada. It may now be out-of-date.
In addition to this official charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at:

       Additional NEMO Web Page

Last Modified: 2005-10-03


TJ Kniveton <tj@kniveton.com>
Thierry Ernst <ernst@sfc.wide.ad.jp>

Internet Area Director(s):

Mark Townsley <townsley@cisco.com>
Margaret Wasserman <margaret@thingmagic.com>

Internet Area Advisor:

Margaret Wasserman <margaret@thingmagic.com>

Technical Advisor(s):

Steven Bellovin <smb@cs.columbia.edu>

Mailing Lists:

General Discussion: nemo@ietf.org
To Subscribe: nemo-request@ietf.org
Archive: http://www.ietf.org/mail-archive/web/nemo/index.html

Description of Working Group:

The NEMO Working Group is concerned with managing the mobility of an
entire network, which changes, as a unit, its point of attachment to
the Internet and thus its reachability in the topology. The mobile
network includes one or more mobile routers (MRs) which connect it to
the global Internet.

A mobile network is assumed to be a leaf network, i.e. it will not
carry transit traffic. However,it could be multihomed, either with a
single MR that has multiple attachments to the internet, or by using
multiple MRs that attach the mobile network to the Internet.

Initially,the WG will assume that none of the nodes behind the MR will
be aware of the network's mobility, thus the network's movement needs
to be completely transparent to the nodes inside the mobile
network. This assumption will be made to accomodate nodes inside the
network that are not generally aware of mobility.

A basic approach for network mobility support is for each Mobile
Router to have a Home Agent, and use bidirectional tunneling between
the MR and HA to preserve session continuity while the MR moves. The
MR will acquire a Care-of-address from its attachment point much like
what is done for Mobile Nodes using Mobile IP. This approach allows
nesting of mobile networks, since each MR will appear to its
attachment point as a single node.

The WG will take a stepwise approach by standardizing some basic
support mechanisms based on the bidirectional tunneling approach, and
at the same time study the possible approaches and issues with
providing more optimal routing than can be had with (potentially
nested) tunneling. However, the WG is not chartered to actually
standardize a solution to such route optimization for mobile networks
at this point in time.

The WG will work on:

- A threat analysis and security solution for the basic problem
(tunneling between HA and MR)

- A solution to the basic problem for both IPv4 and IPv6. The solution
will allow all nodes in the mobile network to be reachable via
permanent IP addresses, as well as maintain ongoing sessions as the MR
changes its point of attachment within the topology. This will be done
by maintaining a bidirectional tunnel between the MR and its Home
Agent. The WG will investigate reusing the existing Mobile IPv6
mechanisms for the tunnel management, or extend it if deemed

- An informational document which specifies a detailed problem
statement for route optimization and looks at various approaches to
solving this problem. This document will look into the issues and
tradeoffs involved in making the network's movement visible to some
nodes, by optionally making them "NEMO aware". The interaction between
route optimization and IP routing will also be described in this
document. Furthermore, security considerations for the various
approaches will also be considered.

The WG will:

- Ensure that solutions will scale and function for the different
mobile network configurations, without requiring changes to
Correspondent Nodes in the Internet. All solutions will aim at
preserving route aggregation within the Internet and will satisfy an
acceptable level of security (a thorough survey of new threats and an
analysis of their severity will be conducted)

- Ensure that various mechanisms defined within other IETF WGs will be
useful for mobile networks. To achieve this, the NEMO WG will interact
with other WGs when needed, and may place requirements on the
protocols developed by those WGs.

The WG will not:

- consider routing issues inside the mobile network. Existing routing
protocols (including MANET protocols) can be used to solve these

Goals and Milestones:

Done  Submit terminology and requirements documents (for Basic support).
Done  Submit NEMO Basic Support to IESG
Done  Submit WG draft -00 on Threat Analysis and Security Requirements for NEMO.
Done  Submit WG draft -00 on Multihoming Problem Statement
Done  Submit WG draft -00 on NEMO Basic Support Usages
Done  Submit WG draft -00 on Prefix Delegation for NEMO
Done  Submit WG draft -00 on MIB for NEMO Basic Support
Aug 2005  Submit Terminology as Informational to IESG
Aug 2005  Submit Goals and Requirements as Informational to IESG
Aug 2005  Submit WG draft -00 on Analysis of the Solution Space for Route Optimization
Nov 2005  Shut down or recharter the WG to solve route optimization


  • draft-ietf-nemo-requirements-05.txt
  • draft-ietf-nemo-terminology-04.txt
  • draft-ietf-nemo-home-network-models-05.txt
  • draft-ietf-nemo-multihoming-issues-04.txt
  • draft-ietf-nemo-mib-01.txt
  • draft-ietf-nemo-ro-problem-statement-01.txt
  • draft-ietf-nemo-dhcpv6-pd-00.txt
  • draft-ietf-nemo-prefix-delegation-00.txt
  • draft-ietf-nemo-ro-space-analysis-01.txt

    Request For Comments:

    RFC3963 Standard Network Mobility (NEMO) Basic Support Protocol

    Current Meeting Report

    # NEMO WG WEDNESDAY 9, NOVEMBER 2005 13:00-15:00
    # 64th IETF Meeting Vancouver
    # http://www.ietf.org/html.charters/nemo-charter.html
    # All NEMO WG related documents available on
    # http://www.mobilenetworks.org/nemo
    # Slides will be posted in http://www.mobilenetworks.org/nemo/ietf64/
    # and are available in the IETF proceedings.
    1  Welcoming, Agenda Bashing, TAHI announcement and WG doc status  ................ 05mins
    2. WG Documents Status & Last Calls
    - Would like some working group input on MIB and Prefix Delegation drafts. Not having a
      discussion on them today, but feel free to discuss on the mailing list.
    2a WG Last Call: NEMO Terminology ................................................. 10mins
       Thierry Ernst
       Issues: http://www.sfc.wide.ad.jp/~ernst/nemo/
    - Last call was on October 26; no comments.
    - Thierry went through the list of open issues.
    - Issue 15: there were comments that the i-face and e-face may not be helpful in clearing
      up potential confusion, as was previously discussed. Decided to eliminate them from the
    - Question: how is NEMO-link different than a normal link?
    - Goal is to put this through; it can be updated later to contain necessary terms (i.e. RO
      or MH)
    2b NEMO Requirement ............................................................... 05mins
       Thierry Ernst
       Issues: http://www.sfc.wide.ad.jp/~ernst/nemo/
    - Issues discussed; this document will also move forward to IESG with Terminology.
    2c NEMO Home Network Models ....................................................... 10mins 
       Vijay Devarapalli 
    - Describes different ways of configuring home network (4 ways).
    - Went through a couple of reviews.
    - MR configuring home address from MNP; text added to clarify.
    - Emulate returning to virtual home link: too complicated; text removed from appendix.
    - Submitted to the IESG.
    3  Analysis of Multihoming in Network Mobility Support ............................ 15mins
       ChanWah Ng
       Issue List:
    - Changes from last version. Scenarios updated. Modification to section 4.
    - New issue for preference settings. MNN may need to specify preferences to MR.
    - Section 5 modified to identify important issues and make recommendations.
    - Chan-wah went over the various issues in more detail, as on the slides.
    - Attempted to take a poll whether various issues are relevant to the working group. But
      there was some confusion and inability to ask all of these various questions.
    - Many questions regarding where specific items should be worked on came up. There was a
      heated discussion on the matrix contained in the document, and whether the work should be
      assumed to happen / assigned to other working groups.
    - The intent was cleared up, that it was simply an attempt to figure out what issues are
      most important to solve in NEMO, and not to assign work to anyone else. However, it is
      appropriate to communicate important issues for NEMO to other groups so they are aware
      of what might be relevant to work on.
    - Choosing default routers - shouldn't this be solved? IPv6 would be the best group, but
      it is closing down.
       Purpose: Get WG consensus on the recommendations regarding issues
       to be solved in which respective WG.
    4  NEMO Routing Optimization
    4a Status of the NEMO RO Problem Statement draft .................................. 10mins
       Masafumi Watari
    - Several reviews received
    - Text added to clarify sub-optimal routing effects on TCP
    - "Deadlock" changed to "stalemate", and questions about "sub-optimal", "mult-angular",
      "pinball" routing, etc.
    - Questions about what are problems, vs. efficiency issues
    - Next version will be published with the latest suggestions, and WG last call will happen.
    4b 1st Presentation of the NEMO RO Solution Space Analysis draft .................. 20mins
       ChanWah Ng 
    - Chan-wah went over the scenarios, as shown in the slides.
    - RO requires changes in the CN (at least in MIP). Consider coordinating new work on RO
      to support MIP and NEMO. Only one set of changes in CN would be required.
    - Agreement that the draft meets the expectation of the working group.
    - Comment that things are getting too complicated in describing a big problem -- keep it
      smaller to be more solvable. Would be nice to have a set of requirements in the draft.
    - Might want to add route optimization that deals with firewalls and proxy servers, as in
      corporate networks.
    5  NEMO v4 and NEMO v6
    5a Status of the Mip6trans DT (presentation in the MIP6 WG) ....................... 05mins 
       Vijay Deverapalli 
    - Update / FYI on design team work. The technical update in more detail happened in the
      MIP6 working group, the following day.
    - Q: anything to force NAT traversal? A: We are still discussing that.
    5b IPv4 Mobile Host/Network support for NEMO Basic Support Protocol ............... 10mins
       Keiichi Shima
       Purpose: about some detailed procedures of supporting IPv4 host/net
       which is not currently dealt with in
    - Described the shortcomings of the current v4traversal draft, and how his contribution
      will fill in these missing pieces.
    - WG polled on whether to merge this work with design team's work; answer was yes.
    5c NEMO Basic Support and IPv4 .................................................... 10mins
       Alex Petrescu & Kent Leung
    - Alexandru presented details on the draft that has been submitted. This draft is based on
      the protocol Cisco developed and has been using, with some new features added.
      It is for IPv4-only networks
    - Discussion on how this should be handled by the NEMO working group
    - Decided to allow it to proceed as informational WG document, and not spend time on getting
      it through the standards-track process.
    - Distinction was presented, where items (5a) and (5b) above are for networks that want to
      transport v4 traffic over v6 networks, or v6 traffic in v4 networks. (5c) is for networks
      that are v4-only, and don't have any plans to upgrade to v6, so they need Mobile IPv4-
      based Network Mobility support.
    6  NEMO WG Status and Charter ..................................................... 15mins
    - Most of the existing charter items are done or almost done.
    - Question as to where the working group should head next?
    - Presentation of some possible topics
    - Key is to focus on issues that are actually relevant to deployment, and solve an immediate
      problem. Some of the multihoming and route optimization topics don't meet this criterion.
    - Operational issues, combined with finishing technical work leading from current tasks,
      will be key to producing useable documents.
    - Home Agent distribution important to AKEA (?) Aeronautical group, which had a meeting
      yesterday in Montreal.
    - Comment from AD: There are additional filters that should be used before chartering:
      - Are the items well-defined?
      - Are there existing proposals in this area that could be a basis of work?
      - Are people willing to work on them?
      It would be really interesting if people have thoughts on how these things should be
      prioritized. We're not going to charter 2-3 years out.
    7  Conclusion / Wrap Up ........................................................... 05mins


    Multihoming Analysis
    RO Problem Statement
    RO Solution Space Analysis
    RO Next Steps
    Home Network Models
    MIP6trans DT Status Report
    IPv4 Support with NEMO Basic Support v6
    NEMO Basic Support for IPv4
    NEMO Rechartering