MEXT Working Group Brian Haley
Internet Draft Hewlett-Packard
Intended status: Standards Track Sri Gundavelli
Expires: January, 2009 Cisco Systems
August 14, 2008
Mobile IPv6 Generic Signaling Message
draft-ietf-mext-generic-signaling-message-00.txt
Status of this Memo
By submitting this Internet-Draft, each author represents that any
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
aware will be disclosed, in accordance with Section 6 of BCP 79.
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 specifies two new Mobility Header message types that
allow Mobile IPv6 entities to send and receive generic signaling
messages.
Haley Expires - January 2008 [Page 1]
Mobile IPv6 Generic Signaling Message August 2008
Table of Contents
1. Introduction...................................................2
2. Terminology....................................................3
3. Generic Signaling Messages.....................................3
3.1 Generic Signaling Message..................................4
4. Generic Signaling Sub-types....................................5
4.1 Generic Signaling Option Sub-type..........................5
4.2 Generic Signaling Request Sub-type.........................6
4.3 Generic Signaling Acknowledgement Sub-type.................7
5. Sending Generic Signaling Messages.............................8
5.1 Sending Generic Signaling Option Messages..................8
5.2 Sending Generic Signaling Request Messages.................8
5.3 Sending Generic Signaling Acknowledgement Messages.........9
6. Receiving Generic Signaling Messages...........................9
6.1 Receiving Generic Signaling Option Messages...............10
6.2 Receiving Generic Signaling Request Messages..............10
6.2.1 Mobile Node Operation...................................10
6.2.2 Home Agent Operation....................................10
6.2.3 Retransmissions.........................................11
7. Protocol Constants............................................11
8. IANA Considerations...........................................11
9. Security Considerations.......................................12
10. References...................................................12
10.1 Normative Reference......................................12
10.2 Informative references...................................12
Acknowledgments..................................................12
Author's Addresses...............................................12
1. Introduction
RFC 3775 [RFC3775] contains no provision for Mobile IPv6 entities,
such as a home agent or mobile node, to send and receive signaling
messages during a mobility session.
This document describes a generic signaling message protocol that can
be used by Mobile IPv6 entities for sending and receiving signaling
events. Two messages are defined - one that does not employ IPsec
protection, and one that does.
It also provides common semantics and a framework that can be used
for defining new event types, and carrying them using the protocol
defined in this document.
The document does not define any specific events, or the
corresponding actions that the receiver is required to do upon
receiving an event. The receiver actions specified in this document
Haley Expires - January 2008 [Page 2]
Mobile IPv6 Generic Signaling Message August 2008
are within the scope of the message delivery and acknowledgment that
are common to all events carried using this messaging protocol.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119].
3. Generic Signaling Messages
The messages described below follow the Mobility Header format
specified in Section 6.1 of [RFC3775]:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Proto | Header Len | MH Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
. .
. Message Data .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Haley Expires - January 2008 [Page 3]
Mobile IPv6 Generic Signaling Message August 2008
3.1 Generic Signaling Messages
The Generic Signaling messages are used by the home agent to notify
the mobile node, or vice-versa, that there is an event that requires
attention. This packet is sent as described in Section 5.
The Generic Signaling messages use the MH Type value (TBD1) or
(TBD2). When either value is indicated in the MH Type field, the
format of the Message Data field in the Mobility Header is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Sub-Type specific data .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sub-Type
A 16-bit unsigned integer. This field describes the particular
type of notification which is carried in the Generic Signaling
message.
This specification defines three Sub-types valid for the Generic
Signaling messages.
Sub-Type specific data
Variable-length field containing data specific to the Sub-Type.
This could be zero bytes in length.
This specification defines three Sub-type data layouts valid for
the Generic Signaling messages.
Mobility options
Haley Expires - January 2008 [Page 4]
Mobile IPv6 Generic Signaling Message August 2008
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero of more TLV-encoded mobility options. The encoding
and format of defined options MUST follow the format specified in
Section 6.2 of [RFC3775]. The receiver MUST ignore and skip any
options with it does not understand.
This specification does not define any options valid for the
Generic Signaling messages.
4. Generic Signaling Sub-types
4.1 Generic Signaling Option Sub-type
The Generic Signaling Option sub-type specifies an un-bounded
signaling message. This packet is sent as described in Section 5.
The Generic Signaling Option uses the sub-type value 0 (zero). When
this value is indicated in the Sub-Type field, there is no data
contained in the Sub-Type Specific Data field in the Generic
Signaling message, there are only Mobility Options, and the format is
as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Mobility options
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero of more TLV-encoded mobility options. The encoding
and format of defined options MUST follow the format specified in
Section 6.2 of [RFC3775]. The receiver MUST ignore and skip any
options which it does not understand.
This specification does not define any options valid for the
Generic Signaling Option message.
If no options are present in this message, no padding is necessary
and the Header Len field in the Mobility Header will be set to 0.
Haley Expires - January 2008 [Page 5]
Mobile IPv6 Generic Signaling Message August 2008
4.2 Generic Signaling Request Sub-type
The Generic Signaling Request sub-type specifies a sequenced type of
signaling message. This packet is sent as described in Section 5.
The Generic Signaling Request uses the sub-type value 1. When this
value is indicated in the Sub-Type field, the format of the Sub-Type
Specific Data field in the Generic Signaling message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |A| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sequence Number
A 16-bit unsigned integer used by the receiving node to sequence
Signaling Requests and by the sending node to match a returned
Signaling Acknowledgement with this Signaling Request.
Acknowledge (A)
The Acknowledge (A) bit is set by the sender to request a Signaling
Acknowledgement (Section 4.3) be returned upon receipt of a
Signaling Request.
Reserved
These fields are unused. They MUST be initialized to zero by the
sender, and MUST be ignored by the receiver.
Mobility options
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero of more TLV-encoded mobility options. The encoding
and format of defined options MUST follow the format specified in
Section 6.2 of [RFC3775]. The receiver MUST ignore and skip any
options with it does not understand.
Haley Expires - January 2008 [Page 6]
Mobile IPv6 Generic Signaling Message August 2008
This specification does not define any options valid for the
Signaling Request message.
If no options are present in this message, no padding is necessary
and the Header Len field in the Mobility Header will be set to 0.
4.3 Generic Signaling Acknowledgement Sub-type
The Generic Signaling Acknowledgement sub-type is used to acknowledge
receipt of a Generic Signaling Request (Section 4.2). This packet is
sent as described in Section 5.
The Generic Signaling Acknowledgement uses the Sub-Type value 2.
When this value is indicated in the Sub-Type field, the format of the
Sub-type Specific Data field in the Generic Signaling message is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sequence Number
The sequence number in the Signaling Acknowledgement is copied from
the sequence number field in the Signaling Request. It is used by
the receiving node in matching this Signaling Acknowledgement with
an outstanding Signaling Request.
Status
8-bit unsigned integer indicating the disposition of the Signaling
Request. Values of the Status field less than 128 indicate that
the Signaling Request was accepted by the receiving node. Values
greater than or equal to 128 indicate that the Signaling Request
was rejected by the receiving node. The following Status values
are currently defined:
0 Signaling Request accepted
Haley Expires - January 2008 [Page 7]
Mobile IPv6 Generic Signaling Message August 2008
128 Reason unspecified
129 Administratively prohibited
130 Insufficient resources
131 Unsupported mobility option
132 Not home agent for this mobile node
Mobility options
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero of more TLV-encoded mobility options. The encoding
and format of defined options MUST follow the format specified in
Section 6.2 of [RFC3775]. The receiver MUST ignore and skip any
options with it does not understand.
This specification does not define any options valid for the
Signaling Request sub-type.
If no options are present in this message, no padding is necessary
and the Header Len field in the Mobility Header will be set to 0.
5. Sending Generic Signaling Messages
When sending a Generic Signaling message, the sending node constructs
the packet as it would any other Mobility Header, except:
o The MH Type field MUST be set to (TBD1) if IPsec protection of
the message is not required.
o The MH Type field MUST be set to (TBD2) if IPsec protection of
the message is required. In this case, the Generic Signaling
Request message MUST use the home agent to mobile node IPsec ESP
authentication SA for integrity protection
5.1 Sending Generic Signaling Option Messages
When sending a Generic Signaling Option, the sending node just adds
mobility options to the message.
5.2 Sending Generic Signaling Request Messages
When sending a Generic Signaling Request message, the sending node
constructs the packet as specified in Section 5, except:
Haley Expires - January 2008 [Page 8]
Mobile IPv6 Generic Signaling Message August 2008
o The Acknowledge (A) bit MAY be set to indicate the receiver must
send a Generic Signaling Acknowledgement in response to this
Generic Signaling Request.
5.3 Sending Generic Signaling Acknowledgement Messages
A Generic Signaling Acknowledgement message should be sent to
indicate receipt of a Generic Signaling Request as follows:
o If the Generic Signaling Request was discarded because it does
not meet the requirements as specified in [RFC3775] described in
Section 6, a Generic Signaling Acknowledgement MUST NOT be sent.
Otherwise, the treatment depends on the below rule.
o If the Acknowledgement (A) bit is set in the Generic Signaling
Request, a Generic Signaling Acknowledgement MUST be sent.
Otherwise, the treatment depends on the below rule.
o If the Generic Signaling Request was discarded for any other
reason, a Generic Signaling Acknowledgement SHOULD be sent.
If the Source Address field of the IPv6 header that carried the
Generic Signaling Request does not contain a unicast address, the
Generic Signaling Acknowledgement MUST NOT be sent, and the Generic
Signaling Request packet MUST be silently discarded. Otherwise, the
acknowledgement MUST be sent to the Source Address.
6. Receiving Generic Signaling Messages
Upon receiving a Generic Signaling message, the Mobility Header MUST
be verified as specified in [RFC3775], specifically:
o The Checksum, MH type, Payload Proto and Header Len fields MUST
meet the requirements of Section 9.2 of [RFC3775].
o If the MH Type field is set to (TBD2) (IPsec protection of the
message is required), then the packet MUST be covered by the
home agent to mobile node IPsec ESP authentication SA for
integrity protection.
If the packet is dropped due to the above tests, the receiving node
MUST follow the processing rules as Section 9.2 of [RFC3775]. For
example, it MUST send a Binding Error message with the Status field
set to 2 (unrecognized MH Type value) if it does not support the
message type.
o If the Generic Signaling message is valid according to the tests
above, then it is processed according to the rules specific to
the Sub-Type specified in the header.
Haley Expires - January 2008 [Page 9]
Mobile IPv6 Generic Signaling Message August 2008
Subsequent checks depend on the current mode of operation of the
node.
6.1 Receiving Generic Signaling Option Messages
If the Generic Signaling Option message is valid according to the
tests in Section 6, then it is processed further as follows:
o If the receiving node does not allow Generic Signaling Option
messages, or does not support the type of Mobility Option in the
message, it MUST reject the request and SHOULD silently discard
the message.
Subsequent checks depend on the current mode of operation of the
node.
6.2 Receiving Generic Signaling Request Messages
If the Generic Signaling Request message is valid according to the
tests in Section 6, then it is processed further as follows:
o If the receiving node does not allow Generic Signaling Request
messages, it MUST reject the request and SHOULD return a Generic
Signaling Acknowledgement to the sender in which the Status
field is set to 129 (administratively prohibited).
o If the receiving node does not support the type of Mobility
Option in the Generic Signaling Request message, it MUST reject
the request and SHOULD return a Generic Signaling
Acknowledgement to the sender in which the Status field is set
to 131 (unsupported mobility option).
Subsequent checks depend on the current mode of operation of the
node.
6.2.1 Mobile Node Operation
If the mobile node rejects the Generic Signaling Request message for
any other reason than specified in Section 6, it SHOULD return a
Generic Signaling Acknowledgement to the home agent in which the
Status field is set to 128 (reason unspecified).
6.2.2 Home Agent Operation
If the receiving node is a home agent, it MUST perform these
additional checks:
Haley Expires - January 2008 [Page 10]
Mobile IPv6 Generic Signaling Message August 2008
o If the home agent has no entry marked as a home registration in
its Binding Cache for this mobile node, then this node MUST
reject the request and SHOULD return a Generic Signaling
Acknowledgement to the mobile node in which the Status field is
set to 132 (not home agent for this mobile node).
o If the home agent cannot process the Generic Signaling Request
message because it is over-utilized, it MUST reject the request
and SHOULD return a Generic Signaling Acknowledgement to the
mobile node in which the Status field is set to 130
(insufficient resources).
If the home agent rejects the Generic Signaling Request message for
any other reason, it SHOULD return a Generic Signaling
Acknowledgement to the mobile node in which the Status field is set
to 128 (reason unspecified).
6.2.3 Retransmissions
If the sender has set the Acknowledge (A) bit in the Generic
Signaling Request, but does not receive a Generic Signaling
Acknowledgement, then it MAY retransmit the message, until a response
is received. The initial value for the retransmission timer is
INITIAL_MH_SIGNALING_TIMEOUT. The retransmissions by the sender MUST
use an exponential back-off mechanism, in which the timeout period is
doubled upon each retransmission, until either the sender gets a
response from the target node, or the timeout period reaches the
value MAX_MH_SIGNALING_TIMEOUT.
7. Protocol Constants
INITIAL_MH_SIGNALING_TIMEOUT 5 seconds
MAX_MH_SIGNALING_TIMEOUT 20 seconds
8. IANA Considerations
Two new Mobility Header types are required for the following new
message described in Section 2:
(TBD1) Generic Signaling Message with
(TBD2) Secure Generic Signaling Message
New Generic Signaling Message Sub-Types are required for the
following described in Section 4:
Haley Expires - January 2008 [Page 11]
Mobile IPv6 Generic Signaling Message August 2008
0 Generic Signaling Option
1 Generic Signaling Request
2 Generic Signaling Acknowledgement
9. Security Considerations
Considerations have been made to support an unprotected Generic
Signaling Message type, MH type (TBD1). This message does not use
any IPsec protection.
In addition, a secure message, called the Secure Generic Signaling
message, MH type (TBD2), is specified. This message MUST use the
home agent to mobile node IPsec ESP encryption SA for confidentiality
protection, and MUST use the home agent to mobile node IPsec ESP
authentication SA for integrity protection. This message type SHOULD
be used for signaling messages that update binding cache state on
either system.
The Secure Generic Signaling message MAY use the IPsec ESP SA in
place for Binding Updates and Acknowledgements as specified in
Section 5.1 of [RFC3775], in order to reduce the number of configured
security associations. This also gives the message authenticity
protection.
10. References
10.1 Normative Reference
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3775] Johnson, D. Perkins, C., and Arkko, J., "Mobility Support
in IPv6", RFC 3775, June, 2004.
10.2 Informative references
Acknowledgments
Thanks to Hui Deng, James Kempf and Vijay Devarapalli for their
initial review of the draft.
Author's Addresses
Brian Haley
Hewlett-Packard Company
110 Spitbrook Road
Haley Expires - January 2008 [Page 12]
Mobile IPv6 Generic Signaling Message August 2008
Nashua, NH 03062, USA
Email: brian.haley@hp.com
Sri Gundavelli
Cisco Systems
170 W.Tasman Drive
San Jose, CA 95134, USA
Email: sgundave@cisco.com
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Haley Expires - January 2008 [Page 13]
Mobile IPv6 Generic Signaling Message August 2008
Acknowledgement
Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA).
Haley Expires - January 2008 [Page 14]
