draft-ietf-mip6-ha-switch-04.txt   draft-ietf-mip6-ha-switch-05.txt 
Mobile IPv6 B. Haley Mobile IPv6 B. Haley
Internet Draft Hewlett-Packard Internet Draft Hewlett-Packard
Document: draft-ietf-mip6-ha-switch-04.txt V. Devarapalli Document: draft-ietf-mip6-ha-switch-05.txt V. Devarapalli
Intended status: Standards Track Azaire Networks Intended status: Standards Track Azaire Networks
Expires: April 26, 2008 H. Deng Expires: May 16, 2008 H. Deng
Hitachi China Mobile
J. Kempf J. Kempf
DoCoMo USA Labs DoCoMo USA Labs
October 26, 2007 November 16, 2007
Mobility Header Home Agent Switch Message Mobility Header Home Agent Switch Message
draft-ietf-mip6-ha-switch-04.txt draft-ietf-mip6-ha-switch-05.txt
Status of this Memo Status of this Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 2, line 8 skipping to change at page 2, line 8
Abstract Abstract
This document specifies a new Mobility Header message type that can This document specifies a new Mobility Header message type that can
be used between a home agent and mobile node to signal a mobile node be used between a home agent and mobile node to signal a mobile node
that it should acquire a new home agent. that it should acquire a new home agent.
Table of Contents Table of Contents
1. Introduction...................................................2 1. Introduction...................................................2
2. Terminology....................................................2 2. Terminology....................................................3
3. Scenarios......................................................3 3. Scenarios......................................................3
3.1 Overloaded.................................................3 3.1 Overloaded.................................................3
3.2 Load Balancing.............................................3 3.2 Load Balancing.............................................3
3.3 Maintenance................................................3 3.3 Maintenance................................................3
3.4 Functional Load Balancing..................................3 3.4 Functional Load Balancing..................................3
3.5 Home Agent Renumbering.....................................4 3.5 Home Agent Renumbering.....................................4
4. Home Agent Switch Message......................................4 4. Home Agent Switch Message......................................4
5. Home Agent Operation...........................................6 5. Home Agent Operation...........................................6
5.1 Sending Home Agent Switch Messages.........................6 5.1 Sending Home Agent Switch Messages.........................6
5.2 Retransmissions............................................7 5.2 Retransmissions............................................7
skipping to change at page 2, line 35 skipping to change at page 2, line 35
9. IANA Considerations............................................9 9. IANA Considerations............................................9
10. Security Considerations.......................................9 10. Security Considerations.......................................9
11. References...................................................10 11. References...................................................10
11.1 Normative References.....................................10 11.1 Normative References.....................................10
11.2 Informative references...................................10 11.2 Informative references...................................10
Acknowledgments..................................................10 Acknowledgments..................................................10
Author's Addresses...............................................10 Author's Addresses...............................................10
1. Introduction 1. Introduction
RFC 3775 [2] contains no provision to allow a home agent to inform a RFC 3775 [RFC3775] contains no provision to allow a home agent to
mobile node that it needs to stop acting as the home agent for the inform a mobile node that it needs to stop acting as the home agent
mobile node. For example, a home agent may wish to handoff some of for the mobile node. For example, a home agent may wish to handoff
its mobile nodes to another home agent because it has become some of its mobile nodes to another home agent because it has become
overloaded or it is going offline. overloaded or it is going offline.
This protocol describes a signaling message type that can be used to This protocol describes a signaling message, called the Home Agent
send a handoff notification between a home agent and mobile node. Switch message, that can be used to send a handoff notification
between a home agent and mobile node.
The Home Agent Switch message does not attempt to solve all general
problems related to changing the home agent of a mobile node. In
particular, this protocol does not attempt to solve:
o The case where the Home Address of a mobile node must change in
order to switch to a new home agent. This operation should be
avoided using this message.
o Determining when a home agent should actively move mobile nodes
to another home agent. This decision should be made by a
backend protocol, for example, as described in [draft-mip6-
hareliability].
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [1]. document are to be interpreted as described in RFC-2119 [RFC2119].
3. Scenarios 3. Scenarios
Here are some example scenarios where a home agent signaling message Here are some example scenarios where a home agent signaling message
would be useful. would be useful.
3.1 Overloaded 3.1 Overloaded
There are a number of reasons a home agent might be considered There are a number of reasons a home agent might be considered
overloaded. One might be that it is at, or near, its limit on the overloaded. One might be that it is at, or near, its limit on the
skipping to change at page 4, line 10 skipping to change at page 4, line 19
stay there if it does route optimization. However, if the original stay there if it does route optimization. However, if the original
home agent detects that the mobile node is not doing route home agent detects that the mobile node is not doing route
optimization, but instead reverse-tunneling traffic, it could optimization, but instead reverse-tunneling traffic, it could
redirect the mobile node to a home agent with better data throughput. redirect the mobile node to a home agent with better data throughput.
3.5 Home Agent Renumbering 3.5 Home Agent Renumbering
Periodically, a mobility service provider may want to shut-down home Periodically, a mobility service provider may want to shut-down home
agent services at a set of IPv6 addresses and bring service back up agent services at a set of IPv6 addresses and bring service back up
at a new set of addresses. Note that this may not involve anything at a new set of addresses. Note that this may not involve anything
as complex as IPv6 network renumbering [3], it may just involve as complex as IPv6 network renumbering [RFC4192], it may just involve
changing the addresses of the home agents. With a signaling message, changing the addresses of the home agents. With a signaling message,
the service provider could inform mobile nodes to look for a new home the service provider could inform mobile nodes to look for a new home
agent. agent.
4. Home Agent Switch Message 4. Home Agent Switch Message
The Home Agent Switch message is used by the home agent to signal the The Home Agent Switch message is used by the home agent to signal the
mobile node that it needs to stop acting as the home agent for the mobile node that it needs to stop acting as the home agent for the
mobile node, and that it should acquire a new home agent. Home Agent mobile node, and that it should acquire a new home agent. Home Agent
Switch messages are sent as described in Section 5. Switch messages are sent as described in Section 5.
The message described below follows the Mobility Header format The message described below follows the Mobility Header format
specified in Section 6.1 of [2]: specified in Section 6.1 of [RFC3775]:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Proto | Header Len | MH Type | Reserved | | Payload Proto | Header Len | MH Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | | | Checksum | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | | |
. . . .
. Message Data . . Message Data .
. . . .
skipping to change at page 6, line 6 skipping to change at page 6, line 6
A list of alternate home agent addresses for the mobile node. The A list of alternate home agent addresses for the mobile node. The
number of addresses present in the list is indicated by the "# of number of addresses present in the list is indicated by the "# of
Addresses" field in the Home Agent Switch message. Addresses" field in the Home Agent Switch message.
Mobility options Mobility options
Variable-length field of such length that the complete Mobility Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field Header is an integer multiple of 8 octets long. This field
contains zero or more TLV-encoded mobility options. The encoding contains zero or more TLV-encoded mobility options. The encoding
and format of defined options MUST follow the format specified in and format of defined options MUST follow the format specified in
Section 6.2 of [2]. The receiver MUST ignore and skip any options Section 6.2 of [RFC3775]. The receiver MUST ignore and skip any
which it does not understand. options which it does not understand.
The Binding Refresh Advice mobility option defined in Section 6.2.4 The Binding Refresh Advice mobility option defined in Section 6.2.4
of [2] is valid for the Home Agent Switch message. of [RFC3775] is valid for the Home Agent Switch message.
If no home agent addresses and no options are present in this If no home agent addresses and no options are present in this
message, no padding is necessary and the Header Len field in the message, no padding is necessary and the Header Len field in the
Mobility Header will be set to 0. Mobility Header will be set to 0.
5. Home Agent Operation 5. Home Agent Operation
5.1 Sending Home Agent Switch Messages 5.1 Sending Home Agent Switch Messages
When sending a Home Agent Switch message, the sending node constructs When sending a Home Agent Switch message, the sending node constructs
the packet as it would any other Mobility Header, except: the packet as it would any other Mobility Header, except:
o The MH Type field MUST be set to (TBD). o The MH Type field MUST be set to (TBD).
o If alternative home agent addresses are known, the sending home o If alternative home agent addresses are known, the sending home
agent SHOULD include them in the list of suggested alternate agent SHOULD include them in the list of suggested alternate
home agents. The home agent addresses field should be home agents. The home agent addresses field should be
constructed as described in Section 10.5.1 of [2], which will constructed as described in Section 10.5.1 of [RFC3775], which
randomize addresses of the same preference in the list. will randomize addresses of the same preference in the list.
o The "# of addresses" field MUST be filled-in corresponding to o The "# of addresses" field MUST be filled-in corresponding to
the number of home agent addresses included in the message. If the number of home agent addresses included in the message. If
no addresses are present, the field MUST be set to zero, forcing no addresses are present, the field MUST be set to zero, forcing
the mobile node to perform home agent discovery by some other the mobile node to perform home agent discovery by some other
means. means.
o If the home agent is able to continue offering services to the o If the home agent is able to continue offering services to the
mobile node for some period of time, it MAY include a Binding mobile node for some period of time, it MAY include a Binding
Refresh Advice mobility option indicating the time (in units of Refresh Advice mobility option indicating the time (in units of
4 seconds) until the binding will be deleted. 4 seconds) until the binding will be deleted.
The Home Agent Switch message MUST use the home agent to mobile node The Home Agent Switch message MUST use the home agent to mobile node
IPsec ESP authentication SA for integrity protection. IPsec ESP authentication SA for integrity protection.
A home agent SHOULD send a Home Agent Switch message when a known A home agent SHOULD send a Home Agent Switch message when a known
period of unavailability is pending so the mobile node has sufficient period of unavailability is pending so the mobile node has sufficient
time to find another suitable home agent. time to find another suitable home agent.
The sending node does not need to be the current home agent for the The sending node does not need to be the current home agent for the
mobile node, for example as described in [4], but it MUST have a mobile node, for example as described in [draft-mip6-hareliability],
security association with the mobile node so the message is not but it MUST have a security association with the mobile node so the
rejected. In this case, the Home Agent Switch message SHOULD only message is not rejected. In this case, the Home Agent Switch message
contain the address of the home agent sending the message in the Home SHOULD only contain the address of the home agent sending the message
Agent Addresses field, which implies the mobile node should switch to in the Home Agent Addresses field, which implies the mobile node
using the sender as its new home agent. should switch to using the sender as its new home agent.
5.2 Retransmissions 5.2 Retransmissions
If the home agent does not receive a response from the mobile node - If the home agent does not receive a response from the mobile node -
either a Binding Update message to delete its home binding if it is either a Binding Update message to delete its home binding if it is
the current home agent, or a Binding Update message to create a home the current home agent, or a Binding Update message to create a home
binding if it is not the current home agent, then it SHOULD binding if it is not the current home agent, then it SHOULD
retransmit the message, until a response is received. The initial retransmit the message, until a response is received. The initial
value for the retransmission timer is INITIAL-HA-SWITCH-TIMEOUT. value for the retransmission timer is INITIAL-HA-SWITCH-TIMEOUT.
skipping to change at page 7, line 47 skipping to change at page 7, line 47
binding with the home agent after reaching the timeout period of MAX- binding with the home agent after reaching the timeout period of MAX-
HA-SWITCH-TIMEOUT, the home agent SHOULD NOT make any conclusions HA-SWITCH-TIMEOUT, the home agent SHOULD NOT make any conclusions
about its status. about its status.
In either case, the home agent SHOULD attempt to continue providing In either case, the home agent SHOULD attempt to continue providing
services until the lifetime of the binding expires. services until the lifetime of the binding expires.
Attempts by the mobile node to extend the binding lifetime with a Attempts by the mobile node to extend the binding lifetime with a
Binding Update message SHOULD be rejected, and a Binding Binding Update message SHOULD be rejected, and a Binding
Acknowledgement SHOULD be returned with status value 129 Acknowledgement SHOULD be returned with status value 129
(Administratively prohibited) as specified in Section 6.1.8 of [2]. (Administratively prohibited) as specified in Section 6.1.8 of
[RFC3775].
6. Mobile Node Operation 6. Mobile Node Operation
6.1 Receiving Home Agent Switch Messages 6.1 Receiving Home Agent Switch Messages
Upon receiving a Home Agent Switch message, the Mobility Header MUST Upon receiving a Home Agent Switch message, the Mobility Header MUST
be verified as specified in [2], specifically: be verified as specified in [RFC3775], specifically:
o The Checksum, MH type, Payload Proto and Header Len fields o The Checksum, MH type, Payload Proto and Header Len fields
MUST meet the requirements of Section 9.2 of [2]. MUST meet the requirements of Section 9.2 of [RFC3775].
o The packet MUST be authenticated, either by the home agent to o The packet MUST be covered by the home agent to mobile node
mobile node IPsec ESP authentication SA for integrity IPsec ESP authentication SA for integrity protection.
protection, or a home agent to mobile node authentication
option.
If the packet is dropped due to the above tests, the receiving node If the packet is dropped due to the above tests, the receiving node
MUST follow the processing rules as Section 9.2 of [2] defines. For MUST follow the processing rules as Section 9.2 of [RFC3775] defines.
example, it MUST send a Binding Error message with the Status field For example, it MUST send a Binding Error message with the Status
set to 2 (unrecognized MH Type value) if it does not support the field set to 2 (unrecognized MH Type value) if it does not support
message type. the message type.
Upon receipt of a Home Agent Switch message, the mobile node MUST Upon receipt of a Home Agent Switch message, the mobile node MUST
stop using its current home agent for services and MUST delete its stop using its current home agent for services and MUST delete its
home binding by sending a Binding Update message as described in home binding by sending a Binding Update message as described in
Section 11.7.1 of [2]. This acts as an acknowledgement of the Home Section 11.7.1 of [RFC3775]. This acts as an acknowledgement of the
Agent Switch message. Alternately, if the sender of the message is Home Agent Switch message. Alternately, if the sender of the message
not the current home agent, sending a Binding Update message to is not the current home agent, sending a Binding Update message to
create a home binding will act as an acknowledgement of the Home create a home binding will act as an acknowledgement of the Home
Agent Switch message. Retransmissions of Binding Update messages Agent Switch message. Retransmissions of Binding Update messages
MUST use the procedures described in Section 11.8 of [2]. MUST use the procedures described in Section 11.8 of [RFC3775].
If a Binding Refresh Advice mobility option is present, the mobile If a Binding Refresh Advice mobility option is present, the mobile
node MAY delay the deletion of its home binding and continue to use node MAY delay the deletion of its home binding and continue to use
its current home agent until the calculated time period has expired. its current home agent until the calculated time period has expired.
If the Home Agent Switch message contains a list of alternate home If the Home Agent Switch message contains a list of alternate home
agent addresses, the mobile node SHOULD select a new home agent as agent addresses, the mobile node SHOULD select a new home agent as
described in Section 6.2, and establish the necessary IPsec security described in Section 6.2, and establish the necessary IPsec security
associations with the new home agent by whatever means required as associations with the new home agent by whatever means required as
part of the mobile node/home agent bootstrapping protocol for the part of the mobile node/home agent bootstrapping protocol for the
skipping to change at page 9, line 27 skipping to change at page 9, line 25
7. Operational Considerations 7. Operational Considerations
This document does not specify how an operator might use the Home This document does not specify how an operator might use the Home
Agent Switch message in its network. However, it might be the case Agent Switch message in its network. However, it might be the case
that a home agent provides service for many thousands of mobile that a home agent provides service for many thousands of mobile
nodes. Care should be taken to reduce the signaling overhead on the nodes. Care should be taken to reduce the signaling overhead on the
network required for handing off many mobile nodes to an alternate network required for handing off many mobile nodes to an alternate
home agent. home agent.
In general, switching the home agent of a mobile node should only be
done when absolutely necessary, since it might cause a service
disruption if switch to a new home agent fails, and the mobile node
has to perform home agent discovery.
If this message is being used for load-balancing between a set of
home agents, they should all be configured with the same set of
prefixes so a home agent switch does not require a change of the home
address for a mobile node. That operation is not recommended and
should be avoided.
8. Procotol Constants 8. Procotol Constants
INITIAL-HA-SWITCH-TIMEOUT 5 seconds INITIAL-HA-SWITCH-TIMEOUT 5 seconds
MAX-HA-SWITCH-TIMEOUT 20 seconds MAX-HA-SWITCH-TIMEOUT 20 seconds
9. IANA Considerations 9. IANA Considerations
A new Mobility Header type is required for the following new message A new Mobility Header type is required for the following new message
described in Section 4: described in Section 4:
(TBD) Home Agent Switch message (TBD) Home Agent Switch message
10. Security Considerations 10. Security Considerations
As with other messages in [2], the Home Agent Switch message MUST use As with other messages in [RFC3775], the Home Agent Switch message
the home agent to mobile node ESP encryption SA for confidentiality MUST use the home agent to mobile node ESP encryption SA for
protection, and MUST use the home agent to mobile node ESP confidentiality protection, and MUST use the home agent to mobile
authentication SA for integrity protection. node ESP authentication SA for integrity protection.
The Home Agent Switch message MAY use the IPsec ESP SA in place for The Home Agent Switch message MAY use the IPsec ESP SA in place for
Binding Updates and Acknowledgements as specified in Section 5.1 of Binding Updates and Acknowledgements as specified in Section 5.1 of
[2], in order to reduce the number of configured security [RFC3775], in order to reduce the number of configured security
associations. This also gives the message authenticity protection. associations. This also gives the message authenticity protection.
Some operators may not want to reveal the list of home agents to on- Some operators may not want to reveal the list of home agents to on-
path listeners. In such a case, the Home Agent Switch message should path listeners. In such a case, the Home Agent Switch message should
use the home agent to mobile node IPsec ESP encryption SA for use the home agent to mobile node IPsec ESP encryption SA for
confidentiality protection. confidentiality protection.
11. References 11. References
11.1 Normative References 11.1 Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[2] Johnson, D., Perkins, C., and Arkko, J., "Mobility Support in [RFC3775] Johnson, D., Perkins, C., and Arkko, J., "Mobility Support
IPv6", RFC 3775, June, 2004. in IPv6", RFC 3775, June, 2004.
11.2 Informative References 11.2 Informative References
[3] Baker, F., Lear, E., and Droms, R., "Procedures for Renumbering [RFC4192] Baker, F., Lear, E., and Droms, R., "Procedures for
an IPv6 Network without a Flag Day", RFC 4192, September, 2005. Renumbering an IPv6 Network without a Flag Day", RFC 4192,
September, 2005.
[4] Wakikawa, R. (Editor), "Home Agent Reliability Protocol", draft- [draft-mip6-hareliability] Wakikawa, R. (Editor), "Home Agent
ietf-mip6-hareliability-02.txt, July, 2007. Reliability Protocol", draft-ietf-mip6-hareliability-02.txt, July,
2007.
Acknowledgments Acknowledgments
We would like to thank the authors of a number of previous drafts We would like to thank the authors of a number of previous drafts
that contributed content to this document: that contributed content to this document:
o draft-wakikawa-mip6-nemo-haha-spec-00.txt o draft-wakikawa-mip6-nemo-haha-spec-00.txt
o draft-deng-mip6-ha-loadbalance-02.txt o draft-deng-mip6-ha-loadbalance-02.txt
o draft-kempf-mip6-ha-alert-00.txt o draft-kempf-mip6-ha-alert-00.txt
o draft-haley-mip6-mh-signaling-00.txt o draft-haley-mip6-mh-signaling-00.txt
skipping to change at page 11, line 17 skipping to change at page 11, line 24
Email: vijay.devarapalli@azairenet.com Email: vijay.devarapalli@azairenet.com
James Kempf James Kempf
DoCoMo USA Labs DoCoMo USA Labs
181 Metro Drive 181 Metro Drive
Suite 300 Suite 300
San Jose, CA 95110 USA San Jose, CA 95110 USA
Email: kempf@docomolabs-usa.com Email: kempf@docomolabs-usa.com
Hui Deng Hui Deng
Research & Development Center China Mobile
Hitachi (China), Investment Ltd. 53A, Xibianmennei Ave.
Beijing Fortune Bldg. 1701, 5 Dong San Huan Bei-Lu Xuanwu District
Chao Yang District, Beijing 100004, China Beijing 100053
Email: hdeng@hitachi.cn China
Email: denghui@chinamobile.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
 End of changes. 29 change blocks. 
59 lines changed or deleted 86 lines changed or added

This html diff was produced by rfcdiff 1.34. The latest version is available from http://tools.ietf.org/tools/rfcdiff/