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Versions: 00                                                            
Network Mobility Working Group                          Behcet Sarikaya
Internet Draft                                              Alcatel USA
Document:draft-sarikaya-nemo-archreqs-00.txt
Category: Informational

                                                           October 2002


Architectural Requirements for Base Network Mobility Using Bidirectional
                               Tunneling
                    draft-sarikaya-nemo-archreqs-00.txt


Status of this Memo

   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 working documents as Internet-Drafts.
   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time. It is inappropriate to use Internet- Drafts as reference
   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
   http://www.ietf.org/shadow.html.

   Distribution of this memo is unlimited.



Abstract

   While traditional mobility support deals with providing continuous
   Internet connectivity to mobile hosts (host mobility support),
   network mobility support means dealing with situations where an
   entire network changes its point of attachment to the Internet. Such
   a network is called a mobile network. This document identifies
   architectural entities of network mobility and nested network
   mobility.












Sarikaya                                                             1

              Architectural Requirements for Basic NEMO  October 2002





Table of Contents

Status of this Memo..................................... .........1
Abstract................................................. ........1
Table of Contents........................................ ........2
1. Introduction..................................... ......... ...3
2. Architecture ...... ...... ...... .................... ........3
2.1 Generic Architecture .........................................3
2.2 Mobile IPv4 Considerations ...................................6
3. Security Considerations........................................7
4. References.............................................. ......7
5.  Authors' Addresses....................... . ..................8







































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              Architectural Requirements for Basic NEMO  October 2002


1. Introduction
   This document assumes that the reader is familiar with the
   terminology defined in [1] and problem description in [2] and Mobile
   IPv4 based description in Section 4.5 of [3].

   The purpose of traditional mobility support is to provide continuous
   Internet connectivity to mobile hosts (host mobility support). In
   contrast, network mobility support is concerned with situations where
   an entire network changes its point of attachment to the Internet and
   thus its reachability in the topology. We shall refer to such a
   network as a mobile network. Cases of mobile networks include
   networks attached to people (Personal Area Networks or PAN), and
   networks of sensors deployed in aircrafts, boats, busses, cars,
   train, etc that need a permanent Internet connection. Those mobile
   networks may also provide Internet access to devices carried by
   people (laptop, camera, mobile phone, etc, and PAN).

   There is a desire to achieve two levels of mobility: node mobility
   and network mobility. A passenger is a mobile node which visits a
   mobile network (VMN in a NEMO), and passengers may themselves be
   mobile IP-subnets (NEMO in a NEMO), for example when carrying a PAN.
   Since people move from a NEMO to another, and since instances of
   NEMOs like trains, car, aircrafts cross country boundaries, both VMNs
   and NEMOs are also most likely to cross ISP boundaries and therefore
   to move between topologically distant parts of the Internet. This
   means we must allow VMNs belonging to potentially different
   administrative domains to visit the NEMO.  These instances also
   justify the need to consider potentially large NEMOs containing
   hundreds of hosts and several routers. The train example highlights
   that the number of correspondent nodes could also be very large, and
   that these may be sparsely distributed in the Internet. It also
   justifies the need for true worldwide mobility in the Internet. A
   NEMO may attach to very distant parts of the Internet topology,
   provided it is granted access to it, therefore requiring both Local-
   Area Mobility support and Wide-Area Mobility support.

   The document continues in Section 2 with general requirements on
   architecture.

2. Architecture

2.1 Generic architecture
   A new architectural entity called mobile router (MR) is needed to
   support network mobility. The mobile router (MR) connects the mobile
   network to the home link. In order to provide session continuity to
   the nodes in its network, MR needs a Mobile IP Home Agent (HA) [4].
   MR may have several internal links to which local fixed (LFN) and
   mobile (LMN) nodes are connected (Figure 1). MR and HA together
   provide support for network mobility. HA MUST know that MR is not a
   basic mobile node but a router.




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              Architectural Requirements for Basic NEMO  October 2002


                      +----+
                      |    |
                      | CN |
                      |    |
                      +----+
                        |
                    +------------------------+
                    |                        |
                    |                        |
                    |       Internet         |
                    |                        |
                    |                        |
                    +------------------------+
                         |               |
                      +----+          +----+       +----+
                      |    |  Access  |    |       |    |
                      | AR |  Router  | AR |       | HA |
                      |    |          |    |       |    |
                      +----+          +----+       +----+
                foreign | link          | home link  |
                   -------------     -------------------------
                         |                        |
                      +----+                    +----+
                      | MN |                 |  | MR | Mobile Router
                      +----+                 |--|    |
                                             |  +----+
                                             |     |  internal link 1
                                             |   --------------------
                                             |     |         |
                                             +  +-----+   +-----+
                                             |  |     |   |     |
                                    +-----+  |  |     |   |     |
                                    |     |  |  | LFN |   | LMN |
                                    | LFN |--|  |     |   |     |
                                    |     |  |  +-----+   +-----+
                                    +-----+  |
                                             | internal link 2
   Figure 1. A Mobile Network at its Home Link

   MR has an egress interface to its home link. MR MAY have several
   ingress interfaces to its internal links.

   The mobile network MAY move in its entirety and MAY attach itself to
   another link, e.g. foreign link. This situation is shown in Figure 2.
   MR MUST provide session continuity to all the nodes in its network.


   The correspondent node (CN) MAY be communicating with a mobile node
   (LMN) or with a fixed node (LFN). Base network mobility support MUST
   not require any changes to the correspondent nodes.




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              Architectural Requirements for Basic NEMO  October 2002



                      +----+
                      |    |
                      | CN |
                      |    |
                      +----+
                        |
                    +------------------------+
                    |                        |
                    |                        |
                    |       Internet         |
                    |                        |
                    |                        |
                    +------------------------+
                         |               |
                      +----+          +----+    +----+
                      |    |  Access  |    |    | HA |
                      | AR |  Router  | AR |    |    |
                      |    |          |    |    |    |
                      +----+          +----+    +----+
                foreign | link          |home link |
             ---------------        -------------------------
              |           |
           +----+       +----+
           | MN |    |  | MR | Mobile Router
           +----+    |--|    |
                     |  +----+
                     |     |  internal link 1
                     |   --------------------
                     |     |         |
                     +  +-----+   +-----+
                     |  |     |   |     |
            +-----+  |  |     |   |     |
            |     |  |  | LFN |   | LMN |
            | LFN |--|  |     |   |     |
            |     |  |  +-----+   +-----+
            +-----+  |
                     | internal link 2

   Figure 2. Mobile Network at a Foreign Link

   A mobile router becomes the visiting mobile router (VMR) if it
   connects to another network in mobility. This is called nested
   mobility. An architecture for nested mobility is shown in Figure 3. A
   visiting mobile router (VMR) connects itself to the network in
   mobility by attaching to one of the links, e.g. local link 2. The
   visiting network in mobility may have its own links to which several
   fixed and mobile nodes are connected. HA1 is the home agent for MR
   and HA2 is for VMR.





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              Architectural Requirements for Basic NEMO  October 2002



                      +----+
                      |    |
                      | CN |
                      |    |
                      +----+
                        |
         +----+     +------------------------+
         | HA |     |                        |
         |   2|     |                        |
         +----+     |       Internet         |
            |       |                        |
             ------>|                        |
                    +------------------------+
                        |               |
                      +----+          +----+      +----+
                      |    |  Access  |    |      |    |
                      | AR |  Router  | AR |      | HA |
                      |    |          |    |      |   1|
                      +----+          +----+      +----+
                foreign | link          |home link  |
                   -------------     -------------------------
                         |                        |
                      +----+                    +----+
                      | MN |                 |  | MR | Mobile Router
                      +----+                 |--|    |
                            +---+            |  +----+
                            |LFN|    |       |     |  internal link 1
                            |   |----| +---+ |   --------------------
                            +---+    |-|VMR|-|     |         |
                                     | +---+ +  +-----+   +-----+
                                             |  |     |   |     |
                                    +-----+  |  |     |   |     |
                                    |     |  |  | LFN |   | LMN |
                                    | LFN |--|  |     |   |     |
                                    |     |  |  +-----+   +-----+
                                    +-----+  |
                                             | internal link 2

   Figure 3. Nested Mobility

2.2 Mobile IPv4 Considerations

   In Mobile IPv4, LMNs as well as MR MAY have a Foreign Agent (FA). The
   FA for LMNs MUST be on the internal link(s). MR MAY act as a FA to
   LMNs only if one of MRÆs interfaces directly connect to the internal
   links in the mobile network. Figure 4 shows the use of Mobile IPv4
   when the network in mobility is on a foreign link. MR uses a local FA
   as its foreign agent while serving as FA to LMNs on the links
   attached to its interfaces.




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              Architectural Requirements for Basic NEMO  October 2002



                      +----+
                      |    |
                      | CN |
                      |    |
                      +----+
                        |
                    +------------------------+
                    |                        |
                    |                        |
                    |       Internet         |
                    |                        |
                    |                        |
                    +------------------------+
                         |               |
          +----+      +----+          +----+       +----+
          |    |      |    |  Access  |    |       |    |
          | FA |      | AR |  Router  | AR |       | HA |
          |  mr|      |    |          |    |       |    |
          +----+      +----+          +----+       +----+
             |  foreign | link          |home link   |
             ---------------        -------------------------
              |           |
           +----+       +----+
           | MN |    |  | MR | Mobile Router
           +----+    |--|(FA)|
                     |  +----+
                     |     |internal link 1
                     |   --------------------
                     |     |         |
                     +  +-----+   +-----+
                     |  |     |   |     |
            +-----+  |  |     |   |     |
            |     |  |  | LFN |   | LMN |
            | LFN |--|  |     |   |     |
            |     |  |  +-----+   +-----+
            +-----+  |
                     | internal link 2
   Figure 4. Network mobility and Mobile IPv4
3. Security Considerations
   To be addressed in a separate draft.
4. References

   1 Thierry Ernst, Hong-Yon Lach, "Network Mobility Support
     Terminology ", draft-ernst-nemo-terminology-00.txt, October 2002,
      Work in progress.
   2 Hesham Soliman "Problem Scope" IETF internet-draft draft-soliman-
      nemo-scope-00.txt, October 2002, Work in progress.
   3 Charlie Perkins, "IP Mobility Support for IPv4", IETF RFC 3344,
      August 2002.




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              Architectural Requirements for Basic NEMO  October 2002



   4 David Johnson, Charlie E. Perkins, Jari Arkko, "Mobility Support in
      IPv6", draft-ietf-mobileip-ipv6-19.txt, work in progress, October
      2002.




5. Author's Addresses

   The working group can be contacted via the current chairs:

      Thierry Ernst,
      WIDE Project
      Jun Murai lab. Faculty of Environmental Information,
      Keio University.
      5322 Endo, Fujisawa-shi, Kanagawa 252-8520, Japan.
      Phone : +81-466-49-1100
      Fax   : +81-466-49-1395
      E-mail: ernst@sfc.wide.ad.jp
      Web: http://www.sfc.wide.ad.jp/~ernst/

      Timothy J. Kniveton
      Communications Systems Lab
      Nokia Research Center
      313 Fairchild Drive
      Mountain View, California 94043
      USA
      Phone:  +1 650 625-2025
      Fax:  +1 650 625-2502
      EMail:  Timothy.Kniveton@Nokia.com


   Questions about this memo can also be directed to:

      Behcet Sarikaya
      Network Strategy Group, Mobile Networking Team
      Alcatel USA M/S 026
      1000 Coit Rd.
      Plano, TX 75075 USA
      Email: behcet.sarikaya@alcatel.com
      Phone: (972) 477-2794 Fax: (972) 519-2460












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