Mobility for IPv4 (mip4)
------------------------

 Charter
 Last Modified: 2008-04-23

 Current Status: Active Working Group

 Chair(s):
     Henrik Levkowetz  <henrik@levkowetz.com>
     Pete McCann  <mccap@petoni.org>

 Internet Area Director(s):
     Jari Arkko  <jari.arkko@piuha.net>
     Mark Townsley  <townsley@cisco.com>

 Internet Area Advisor:
     Jari Arkko  <jari.arkko@piuha.net>

 Mailing Lists: 
     General Discussion:mip4@ietf.org
     To Subscribe:      mip4-request@ietf.org
         In Body:       subscribe
     Archive:           http://www.ietf.org/mail-archive/web/mip4/index.html

Description of Working Group:

IP mobility support for IPv4 nodes (hosts and routers) is specified in
RFC3344. RFC 3344 mobility allows a node to continue using its
"permanent" home address as it moves around the Internet. The Mobile
IP protocols support transparency above the IP layer, including
maintenance of active TCP connections and UDP port bindings. Besides
the basic Mobile IPv4 (MIPv4) protocols, several other drafts deal
with concerns such as optimization, security, extensions, AAA support,
and deployment issues.

MIPv4 is currently being deployed on a wide basis (e.g., in cdma2000
networks). The scope of the deployment is on a fairly large scale and
accordingly, the MIP4 WG will focus on deployment issues and on
addressing known deficiencies and shortcomings in the protocol that
have come up as a result of deployment experience. Specifically, the
working group will complete the work items to facilitate interactions
with AAA environments, interactions with enterprise environments when
MIPv4 is used therein, and updating existing protocol specifications
in accordance with deployment needs and advancing those protocols that
are on the standards track.

Work expected to be done by the MIP4 WG as proposed by this charter is
as follows:

1. MIPv4 has been a proposed standard for several years. It has been
adopted by other standard development organizations and has been
deployed commercially. One of the next steps for the WG is to advance
the protocol to draft standard status. As part of advancing base
Mobile IP specs to DS, the MIPv4 NAI RFC (2794) will be revised to
reflect implementation experience.

2. Work items that are pending from the previous Mobile IP WG, which
will be completed by the MIP4 WG, are:

- completion of the MIB for the revised base Mobile IP specification
(2006bis)

- regional registration draft.

3. The MIP4 WG will also complete the work on MIPv4 interactions in
VPN scenarios. This work will involve identifying the requirements and
a solution development for MIPv4 operation in the presence of IPsec
VPNs.

4. Additionally, a proposal has been made for how MOBIKE could work
together with MIPv4. This proposal does not describe any new protocol,
but formulates a best current practice for deploying MOBIKE together
with MIPv4. The working group will adopt and complete this document.

5. Some issues have been raised with respect to RFC3519. These will be
identified and addressed as appropriate, through errata, revision of
RFC 3519, and/or supplemental documents as needed.

6. It has been proposed that the FMIP protocol, which has been
standardised for MIPv6 in the MIPSHOP working group, should also be
published as an experimental protocol for MIPv4. A draft for this
exists. The working group will take up and carry this work forward to
publication

7. An extension to carry generic strings in the Registration Reply
message has been proposed. The purpose is to supply supplemental
human-readable information intended to the MN user. The working group
will complete the specification and applicability statement of such an
extension.

8. RADIUS attributes for MIP4. A set of RADIUS attributes has been
proposed for MIPv4.

The working group will first produce a requirements specification,
describing how the work differs from the requirements in RFC 2977 and
the functionality provided by RFC 4004 (the MIPv4 Diameter App). The
reason why this first step is required is that RFC 3127 shows that
full RFC 2977 functionality can't be provided by even a considerably
extended RADIUS, so we need to match the requirements to what can be
done within RADIUS.

Provided the requirements work finds approval with ADs and RADEXT WG,
the workgroup will complete the specification of MIPv4 RADIUS
attributes, solicit feedback from the RADEXT WG, adjust, and submit
this for publication. Note that the work may require extensions to the
RADIUS attribute space which will be handled outside the MIP4 WG.

9. MIPv4 Extension for Configuration Options.

Several drafts have proposed extensions to help improve configuration
of MIPv4 clients. The latest proposal is for a general configuration
option extension which could carry information such as e.g., DNS
address and DHCP server address. The working group will take on and
complete one proposal for a configuration option extension.

10. Dual-stack Support

There have been several proposals for how to enable an IPv6 connection
over a network that supports Mobile IPv4. A protocol enhancement to
MIPv4 would allow for IPv6 support in a region where Mobile IPv4 has
already been implemented and deployed. This would allow a dual stack
mobile node to maintain IPv6 connectivity when using MIPv4. The
solution would therefore be applicable only to networks that are
not deploying Mobile IPv6.

The working group will take on and complete one proposal for IPv6 over
Mobile IPv4. This work is restricted to a small protocol extension
similar to current Mobile IPv4 functionality. Support for advanced
Mobile IPv6 functionality is strictly outside the scope.

A problem statement covering both Mobile IPv4 and IPv6 dual-stack
issues is expected to come out of MIP6 WG, and will not be developed
in MIP4 WG.


11. MIPv4 Moving Network Support

The Network Mobility (nemo) working group deals with the problem of
mobility of a whole network, such as might exist inside a vehicle,
train, or airplane. The nemo working group has developed draft
specifications for both IPv6 and IPv4 mobile networks. However, it has
been recognized that the IPv4 version of the protocol can be viewed as
an extension of the basic Mobile IPv4 protocol, and there is good 
reason
to do this extension in the mip4 working group. The working group will
take on the MIPv4 network mobility internet draft and progress it along
the standards track. In addition, the working group will take up
extensions to the basic MIPv4 moving network support in the areas of
dynamic prefix assignment and foreign agent support.


12. Asynchronous Notification Mechanism

In some situations, there is a need for Mobile IPv4 entities, such
as the home agent, foreign agent and mobile node to send and
receive asynchronous notification events related to the operation
of the MIPv4 protocol. A couple of examples of such events are
registration revocation from a home agent to a foreign agent in
order to terminate the service (to release resources and end
charging), and notification of pending HA shutdown and indication
of alternative serving HA, from a HA to the mobile node.

The base Mobile IP Specification [RFC3344] does not have a
provision for this. A new MIPv4 message pair which would support
asynchronous notifications, and a notification model describing
how to use these messages has been proposed. The working group
will take on the existing MIPv4 notification message draft as a
starting point, review and update it as needed, and progress it as
a standards track document. In addition, the working group will
also consider defining specific usages of the notification message
based on the examples in the current document.

 Goals and Milestones:

   Done         AAA Keys for MIPv4 to IESG 

   Done         MIPv4 VPN interaction problem statement to IESG 

   Done         Low latency handover to experimental 

   Done         Experimental MIPv4 message and extensions draft to IESG 

   Done         Dynamic Home Agent assignment protocol solution to IESG 

   Done         Revised MIPv4 Challenge/Response (3012bis) to IESG 

   Done         Regional registration document to IESG 

   Done         Generic Strings for MIPv4 (Proposed Std.) to the IESG 

   Done         MIPv4 Mobike interaction (BCP) to the IESG 

   Done         MIPv4 RADIUS Extensions Requirements to the IESG 

   Done         MIPv4 Extension for Config. Options (Proposed Std.) to the IESG 

   Done         FMIPv4 (Experimental) to the IESG 

   Done         MIPv4 VPN interaction (BCP) to the IESG 

   Done         Base MIPv4 Mobile Network Support (Draft Std.) to IESG 

   Feb 2008       Revised MIPv4 specification to IESG for Draft Std. 

   Mar 2008       Dual-stack MIPv4 (Draft Std.) to IESG 

   Mar 2008       Revised MIB for MIPv4 (Proposed Std.) to IESG 

   May 2008       RADIUS Extensions for MIPv4 to the RADEXT WG for comment 

   May 2008       Notification Mechanism (Draft Std.) to IESG 

   Jun 2008       RADIUS Extensions for MIPv4 (Proposed Std.) to the IESG 

   Jul 2008       Revised rfc2794bis (NAI extension) (Draft Std.) to the IESG 

   Aug 2008       MIPv4 Mobile Network Support for FAs (Draft Std.) to IESG 

   Aug 2008       MIPv4 Mobile Network Support Dynamic Address Assignment (Draft 
                Std.) to IESG 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Sep 2003 Aug 2008   <draft-ietf-mip4-rfc2006bis-05.txt>
                The Definitions of Managed Objects for IP Mobility Support 
                using SMIv2, revised 

Jul 2004 Mar 2008   <draft-ietf-mip4-rfc3344bis-06.txt>
                IP Mobility Support for IPv4, revised 

Aug 2006 Feb 2008   <draft-ietf-mip4-dsmipv4-06.txt>
                Dual Stack Mobile IPv4 

Mar 2007 Jul 2008   <draft-ietf-mip4-generic-notification-message-06.txt>
                Generic Notification Message for Mobile IPv4 

Mar 2007 Apr 2008   <draft-ietf-mip4-nemov4-fa-03.txt>
                FA extensions to NEMOv4 Base 

 Request For Comments:

  RFC   Stat Published     Title
------- -- ----------- ------------------------------------
RFC3846Standard  Jul 2004    Mobile IPv4 Extension for AAA Network Access Identifiers 

RFC3957Standard  Mar 2005    Authentication, Authorization, and Accounting (AAA) 
                       Registration Keys for Mobile IPv4 

RFC4064Standard  May 2005    Experimental Message, Extension and Error Codes for 
                       Mobile IPv4 

RFC4093 I    Aug 2005    Problem Statement: Mobile IPv4 Traversal of Virtual 
                       Private Network (VPN) Gateways 

RFC4433 PS   Mar 2006    Mobile IPv4 Dynamic Home Agent Assignment 

RFC4636 PS   Oct 2006    Foreign Agent Error Extension for Mobile IPv4 

RFC4721 PS   Jan 2007    Mobile IPv4 Challenge/Response Extensions (Revised) 

RFC4857 E    Jun 2007    Mobile IPv4 Regional Registration 

RFC4917 PS   Jun 2007    Mobile IPv4 Message String Extension 

RFC4881 E    Jun 2007    Low-Latency Handoffs in Mobile IPv4 

RFC5030 I    Oct 2007    Mobile IPv4 RADIUS requirements 

RFC4988 E    Oct 2007    Mobile IPv4 Fast Handovers 

RFC5177 PS   Apr 2008    Network Mobility (NEMO) Extensions for Mobile IPv4 

RFC5265 PS   Jun 2008    Mobile IPv4 Traversal across IPsec-Based VPN Gateways 

RFC5266BCP  Jun 2008    Secure Connectivity and Mobility Using Mobile IPv4 and 
                       IKEv2 Mobility and Multihoming (MOBIKE)