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INTERNET DRAFT                         Cleve Mickles(Co-Author/Editor)
Document: draft-mickles-v6ops-isp-analysis-00.txt      AOL Time Warner
Expires: Aug  2003                                      February 2003

                  Transition  Analysis for ISP Networks

Status of this Memo
   This document is an Internet-Draft and is subject to 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.
Abstract
   This document provides analysis of how to transition the different
   types of Internet Service Provider (ISP) networks to IPv6.  It
   will provide design recommendations which may be followed to
   successfully deploy IPv6 services on a network that began as an
   IPv4 network. This is the companion document to
   draft-mickles-v6ops-isp-scenarios-04.txt which provides detailed
   background information on all scenarios.

   mail list for the design team: IPV6@LISTSERV.SUP.AOL.COM






















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                Transition  Analysis for ISP Networks      Feb. 2003

Table of Contents
   1.  Introduction................................................3
   2.  Scope of the document.......................................3
   3.  Core/Backbone Networks......................................4
         3.1  IPv6 Routing Considerations..........................4
         3.2  IPv6 Peering Considerations..........................5
         3.3  IPv6 Transition Mechanisms...........................5
         3.4  Security Considerations..............................6
         3.5  Network Management...................................6
    4.  Broadband  HFC/Coax Networks...............................7
         4.1  IPv6 Routing Considerations..........................7
         4.2  IPv6 Transition Mechanisms...........................7
         4.3  Security Considerations..............................7
         4.4  Network Management...................................7
    5.  Broadband DSL Networks.....................................8
         5.1  IPv6 Routing Considerations..........................8
         5.2  IPv6 Transition Mechanisms...........................8
         5.3  Security Considerations..............................8
         5.4  Network Management...................................8
    6.  Narrowband Dialup Networks.................................9
         6.1  IPv6 Routing Considerations..........................9
         6.2  IPv6 Transition Mechanisms..........................10
         6.3  Security Considerations.............................10
         6.4  Network Management..................................10
    7.  Public Wireless LAN.......................................11
         7.1  IPv6 Routing Considerations.........................11
         7.2  IPv6 Transition Mechanisms..........................11
         7.3  Security Considerations.............................11
         7.4  Network Management..................................11
    8.  Broadband Ethernet .......................................12
         8.1  IPv6 Routing Considerations.........................12
         8.2  IPv6 Transition Mechanisms..........................12
         8.3  Security Considerations.............................12
         8.4  Network Management..................................12
     9. Internet Exchange Point...................................13
         9.1  IPv6 Routing Considerations.........................13
         9.2  IPv6 Transition Mechanisms..........................13
         9.3  Security Considerations.............................13
         9.4  Network Management..................................13
   10.0 Security Considerations...................................14
   11.0 Network Management Considerations.........................14
Acknowledgements..................................................14
References........................................................14
Terminology.......................................................14
Author's Addresses................................................15

Copyright
   (C) The Internet Society (2003).  All Rights Reserved.



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                Transition  Analysis for ISP Networks      Feb. 2003

1. Introduction

   This document will provide analysis and recommendations for
   ISPs to use in transitioning their existing IPv4 networks to
   IPv6.  It will show how existing mechanisms can be used to enable
   IPv6 capabilities over IP networking components and highlight any
   known challenges that may arise during a network transition.


2. Scope of the document

   The scope of this document is to cover the major topics ISPs must
   consider in transitioning their IP networks to IPv6.  It is not
   meant to address every detail provided in the scenario document,
   but will highlight those details which are most important to the
   transition.

























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3. Core/Backbone Networks

   Transition to IPv6 in the Core network can be done in multiple
   ways.  The mechanisms discussed below are well known and the
   discussion will be scoped based on the general topology below
   in figure 3.1


                       Trunks to remote sites

                             ^               ^
                             |               |
                            /               /
                           /               /
                        /\/               /
                       /               /\/
                      /               /
                 ____/____       ____/____
                |         |     |         |
                |  CORE1  |     |  CORE2  |
                |_________|     |_________|
      ____________/ | \           | | |
     /              |  \          | | |
    /   +===========|===\=========+ | |
    |  /            |  +=\==========+ |
 ___|_/_         ___|_/_  \      _____|_
|       |       |       |  \____|       |
| BDR1  |       | BDR2  |       | BDR(n)|
|_______|       |_______|       |_______|\
    |               |               |     \
    |               |               |      \
    |               |               |       \_Peering( Direct & IX )
    |               |               |
 ___|___         ___|__          ___|___
|       |       |      |        |       |
| CPE1  |       | CPE2 |        | CPE(n)|
|_______|       |______|        |_______|

            Figure 3.1




3.1 IPv6 Routing Considerations

   In this section we will discuss considerations for the IPv6 in the
   internal network as well as the external networking issues.

   Since IPv4 exists in the Core IGP, IPv6 capabilities must be added

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                Transition  Analysis for ISP Networks      Feb. 2003

   while maintaining IPv4 reachability.  In essence two IGP protocols
   will exist in one routing domain.  This mode is generally referred
   to as dual-stack mode or "ships in the night" mode.  This is not
   an entirely new function of routers since running multiple routing
   protocols on routers has been a fairly common practice.  The
   limitations for this practice include CPU power and memory.

   To add IPv6 capability to the core network, IPv6 routes must be
   present in the IGP.  The choices of IGP for IPv6 networking
   include ISIS and RIPv2.  Ripv2 is the simplest solution.  ISIS has
   the advantage of being able to carry both IPv4 and IPv6 routes in
   one IGP.  OSPFv3 is a potential solution but is not currently
   available and similar to RIPv2 in that it is not backward
   compatible with OSPFv1 which supports IPv4 routes.

   For networks which use OSPF as its IGP for IPv4 routes, the
   recommendation is to continue carrying IPv4 routes in OSPFv1 and
   configure IPv6 routes in ISIS.

   For networks which use ISIS, the recommendation is to add IPv6
   routes to the existing IGP and run IPv4 and IPv6 integrated within
   ISIS.

   As the IPv6 network grows, there will exist routers which are only
   reachable via IPv6.

3.2 IPv6 Peering Considerations

   Generally peering is done on border routers. The two choices for
   IPv6 peering include deploying a separate border router for
   external IPv6 peering or converting existing IPv4 peering routers
   to support IPv6 and IPv4 peering.

   In both cases the border routers will exchange IPv6 reachability
   information using its IGP.

   To exchange IPv6 traffic over an EGP boundary, the routing
   protocol of choice remains BGP.  The EGP boundary can be
   established using either physical circuits or tunneled circuits
   which are discussed below.  The routing table for IPv6 routes is
   separate from the table for Ipv4 routes.

3.3 IPv6 Transition Mechanisms
   Once basic decisions about deploying IPv6 services have been
   determined how to establish connectivity between IPv6 nodes is the
   next step.  Since the transition assumes an IPv4 network exists,
   there will be transitional nodes which operate in dual stack mode.

   There are two choices that may be used to inteconnect IPv6
   capable nodes.  The first is to use physical links between nodes.

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                Transition  Analysis for ISP Networks      Feb. 2003

   This has been standard procedure in networking.  Point-to-point or
   LAN media may be used to establish connectivity and IPv6
   addressing is configured over the link.  The second choice is to
   use "IPv4 over IPv4" tunneling mechanisms to route IPv6 traffic
   over IPv4 networks.

3.4 Network Management

   Since NM systems are used to monitor and configure networks, the
   ability for NM systems to manage IPv6 capable routers must be
   maintained.  While NM systems will reach dual stack routers over
   the IPv4 path, there will be routers which are only reacheable via
   IPv6 and therefore NM systems must have an IPv6 presence to manage
   those devices

3.5 Security Considerations

   Route filtering techniques should continue to be done for IPv6.

   IPv6 networks are open to hacking attempts just as IPv4 networks,
   but the number of potential devices on a network make random port
   scaning less effective.





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4.  Broadband HFC/Coax Networks

   This section describes the infrastructure that exists in today's
   HFC cable networks that support cable modem services to the home.
   Since many cable providers are regional they generally have used
   the backbone ISP networks for transit IP services beyond their
   region.


                    +-----------+
                    |           |
                    |           |
              /-----+           |          +--------+
         WAN <------+   CMTS    |<========>| Modem  |<===> CPE
              \-----+           | Cable    +--------+  |
                |   |           | Network              |
                |   |           |                      |
                |   +-----------+                      |
                |                                      |
                +-------------------+------------------+
                                    |
              "Transparent IP Traffic Through the System"
            Figure 4.2.2




4.1 IPv6 Routing Considerations
4.2 IPv6 Transition Mechanisms
4.2.1 Dual Stack Mode
4.2.2 Tunneling
4.2.3 Physical
4.3 Network Management
4.4 Security Considerations
















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5. Broadband DSL Networks

   This section describes the infrastructure that exists in todays
   High Speed DSL Networks.


Customer Premises | Network Access Provider | Network Service Provider
       CP                     NAP                        NSP

+-----+  +-----+       +-----+
|Hosts|--| DSL +-------+DSLAM|
+-----+  |Modem|       |     +----+
         +-----+       +-----+    |
                                  |
+-----+  +------+                 |  +-----+    +-------+
|Hosts|--|Router|                 +--+ BAS +----+  ISP  |         ISP
+-----+  +--+---+                 +--+     |    |  Edge +===> Network
            |                     |  +-----+    | Router|
         +--+--+                  |             +-------+
         | DSL +---+              |
         |Modem|   |              |
         +-----+   |              |
                   |   +-----+    |
+-----+  +------+  +---+DSLAM+----+
|Hosts|--|Router|  +---+     |
+-----+  +--+---+  |   +-----+
            |      |
         +--+--+   |
         | DSL +---+
         |Modem|
         +-----+

            Figure 5.1





5.1 IPv6 Routing Considerations
5.2 IPv6 Transition Mechanisms
5.2.1 Dual Stack Mode
5.2.2 Tunneling
5.3 Network Management
5.4 Security Considerations





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6.  Narrowband Dialup Networks

   Transitioning the dial up ISP to IPv6 is somewhat straight forward
   since the major network devices in this model reside on a single
   LAN.



+-----+  +------+       +------+
|Hosts|--| 56K  +-------+Modem |          +----------+
+-----+  |Modem |       |Bank  +----------+  ISP 1   |         NSP 1
         +------+       +------+          |  Edge    +=====> Network
                        |      |          | Router   |
                        |      |          +----------+
                        |      |
                        |      |          +----------+
                +-------+      +----------+  ISP 2   |         NSP 2
                |Radius |      |          |  Edge    +=====> Network
                |Server |      |          | Router   |
                +-------+      |          +----------+
                               |
                               |          +----------+
                               +----------+  ISP 3   |         NSP 3
                                          |  Edge    +=====> Network
                                          | Router   |
                                          +----------+

            Figure 6.1





6.1 IPv6 Routing Considerations

   To establish IPv6 connectivity in the dial up environment, the
   devices between the end user host and NSP Network router must be
   IPv6 capable.  The ISP edge router must be a dual-stack router.
   The ISP edge router should have an IPv6 default route for global
   IPv6 reachability.  This can be accomplished via the existing
   physical circuit to the NSP router if the NSP supports IPv6 or to
   a separate NSP' which supports IPv6.  An additional alternative is
   for the ISP router to tunnel IPv6 traffic over IPv4 to an IPv6
   router with global IPv6 reachability.





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6.2 IPv6 Transition Mechanisms
   In the dial up ISP environment the devices between the ISP router
   and host appear to reside on the same LAN. Therefore the devices
   on the LAN must support IPv6.

6.3 Network Management

   Since NM systems are used to monitor and configure networks, the
   ability for NM systems to manage IPv6 capable devices must be
   maintained.  While NM systems will reach dual stack devices over
   the IPv4 path, there will be devices which are only reacheable via
   IPv6 and therefore NM systems must have an IPv6 presence to manage
   those devices.

6.4 Security Considerations

   Route filtering techniques should continue to be done for IPv6.

   IPv6 networks are open to hacking attempts just as IPv4 networks,
   but the number of potential devices on a network make random port
   scaning less effective.




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                Transition  Analysis for ISP Networks      Feb. 2003

7. Public Wireless LAN

   This section describes the infrastructure that exists in today's
   public wireless LAN services.

                                                      +-------+
                                                      | AAA   |
                                                      | Radius|
                                                      | TACACS|
             '---'                                    +-------+
            (      )                                       |
  +-----+  (Wireless)   +----+     /------------\     +-------+
  |Hosts+--(  LAN   )---| AP |----|  Underlying  \--- | ISP   |=>Core
  +-----+  (        )   +----+     \ technology  |    | Edge  |
            (      )                \-----------/     | Router|
             '---'                                    +-------+

           Figure 7.1.1. Physical architecture of WLAN model.




7.1 IPv6 Routing Considerations
7.2 IPv6 Transition Mechanisms
7.2.1 Dual Stack Mode
7.2.2 Tunneling
7.3 Network Management
7.4 Security Considerations






















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8.0 Broadband Ethernet

   This section provides recommendations on how to transition
   Ethernet based residential access networks to IPv6.





8.1 IPv6 Routing Considerations
8.2 IPv6 Transition Mechanisms
8.2.1 Dual Stack Mode
8.2.2 Tunneling
8.3 Network Management
8.4 Security Considerations


































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 9.0 Internet Exchange (IX)

   This section provides recommendations on how to transition IPv4
   Internet exchanges (IX) to IPv6 exchanges.


                                             ______________
        ____________    +----+              /              \
       /            \  /     |           +-(   LHP2 router  )
      (  LHP1 router )+   +--+----+     /   \______________/
       \____________/     |       |----+
                      +---| L2 SW |
     ______________  /    |       |-+    ______________
    /              \+     +---+---+  \  /              \
   (   LHP3 router  )         |       +(   LHP4 router  )
    \______________/          |         \______________/
                          +---+----+
                          |        |        ____________
                          |   IX   |       /            \
                          | router +------(IX subscriber )
                          |        |       \____________/
                          +--------+

                         Figure  9.1


9.1 IPv6 Routing Considerations
9.2 IPv6 Transition Mechanisms
9.2.1 Dual Stack Mode
9.2.2 Tunneling
9.3 Network Management
9.4 Security Considerations



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                Transition  Analysis for ISP Networks      Feb. 2003


10. SECURITY CONSIDERATIONS

   Security concerns will be described within the context of each
   scenario.  After the various scenarios are documented, a
   summarized section including all of the security considerations
   may be provided.

11. NETWORK MANAGEMENT CONSIDERATIONS

   Network Management concerns will be described within the context
   of each scenario.  After the various scenarios are documented, a
   summarized section including all of the Network Management
   considerations may be provided.


ACKNOWLEDGEMENTS
   [1] The comments from the V6OPS working group are appreciated.

REFERENCES

    [ISP Scenarios] Mickles, C., et al: "Transition Scenarios
    for ISP Networks", February 2003,
    draft-mickles-v6ops-isp-scenario-04.txt, work in progress.

    [3gpp analysis] Wiljakka, J., et al: "Analysis on IPv6
    Transition in 3GPP Networks", January 2003,
    draft-ietf-v6ops-3gpp-analysis-01.txt, work in progress.

    [Unman Scenarios] Huitema, C., et al: "Unmanaged Networks
    IPv6 Transition Scenarios", January 2003,
    draft-ietf-v6ops-unman-scenarios-00.txt, work in progress.


TERMS AND ACRONYMS














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 Author's Addresses

   Vladimir Ksinant
   6Wind
   1 place Charles de Gaulle - 78180     Phone: +33139309236
   Montigny Le Bretonneux - France  Email:vladimir.ksinant@6wind.com

   Jae-Hwoon Lee
   Dongguk Univ.
   26, 3 Pil-Dong, Chung-gu,               Phone: +82 2 2260 3849
   Seoul 100-715, Korea                    Email: jaehwoon@dgu.ac.kr

   Myung-Ki Shin
   ETRI PEC
   161 Kajong-Dong, Yusong-Gu,          Phone: +82 42 860 4847
   Taejon 305-350, Korea                Email: mkshin@pec.etri.re.kr

   Aidan Williams
   Motorola Australian Research Centre
   Locked Bag 5028                     Phone: +61 2 9666 0500
   Botany, NSW  1455              Email: Aidan.Williams@motorola.com
   Australia
   URI:   http://www.motorola.com.au/marc/

   Alain Baudot
   France Telecom R&D
   42, rue des coutures           Phone:  +33 2.31.75.94.27
   BP 6243                 Email:  alain.baudot@rd.francetelecom.com
   14066 Caen, FRANCE

   Mikael Lind
   Telia Research
   Vitsandsgatan 9B
   123 86 Farsta                   Phone: +46 70 2406140
   Sweden                          Email: Mikael.e.lind@telia.se

   Cleveland Mickles
   America Online, Inc (owned by AOL Time Warner)
   12100 Sunrise Valley Drive.          Phone:  +1 703-265-5618
   Reston, VA 20191, USA                Email:  micklesc@aol.net







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