draft-ietf-mip4-message-string-ext-03.txt   rfc4917.txt 
MIP4 V. Sastry Network Working Group V. Sastry
Internet-Draft Samsung Electronics Request for Comments: 4917 Samsung Electronics
Intended status: Standards Track K. Leung Category: Standards Track K. Leung
Expires: September 2, 2007 A. Patel A. Patel
Cisco Systems Cisco Systems
March 1, 2007
Mobile IPv4 Message String Extension Mobile IPv4 Message String Extension
draft-ietf-mip4-message-string-ext-03.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 Status of This Memo
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.
This Internet-Draft will expire on September 2, 2007. This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2007).
Abstract Abstract
This document specifies a new extension for use in Mobile IPv4. This This document specifies a new extension for use in Mobile IPv4. This
extension can be added by the Home Agent and the Foreign Agent to extension can be added by the Home Agent and the Foreign Agent to
Registration Reply messages. This extension carries a text string Registration Reply messages. This extension carries a text string
that is intended for the user of the Mobile Node. that is intended for the user of the Mobile Node.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology .....................................................2
3. Mobile IPv4 Message String Extension Format . . . . . . . . . 5 3. Mobile IPv4 Message String Extension Format .....................2
4. Operation and Use of the Message String Extension . . . . . . 6 4. Operation and Use of the Message String Extension ...............3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 5. Security Considerations .........................................4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations .............................................4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgements ................................................5
8. Normative References . . . . . . . . . . . . . . . . . . . . . 10 8. Normative References ............................................5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . . . 12
1. Introduction 1. Introduction
This document specifies a new skippable extension that can be added This document specifies a new skippable extension that can be added
by the Foreign Agent and Home Agent in any registration message by the Foreign Agent and Home Agent in any registration message
targeted for the Mobile Node. Such a message may be either a targeted for the Mobile Node. Such a message may be either a
Registration Reply or Registration Revocation (i.e. co-located Registration Reply or Registration Revocation (i.e., co-located
Care-of Address mode). For the Registration Reply message, this Care-of Address mode). For the Registration Reply message, this
extension can be added regardless of whether the registration has extension can be added regardless of whether the registration has
succeeded or failed. succeeded or failed.
The content of the text string in this extension and its usage by the The content of the text string in this extension and its usage by the
Mobile Node is implementation specific. The text string in this Mobile Node is implementation specific. The text string in this
extension is intended for the user of the Mobile Node. For example, extension is intended for the user of the Mobile Node. For example,
this message can be displayed on the Mobile Node's user interface, this message can be displayed on the Mobile Node's user interface,
logged, or handled in any other implementation dependent way, logged, or handled in any other implementation dependent way,
depending on the form of the Mobile Node. depending on the form of the Mobile Node.
Typical contents of the text string will indicate a registration Typical contents of the text string will indicate a registration
failure reason, or give a welcome message on successful registration. failure reason, or give a welcome message on successful registration.
This is important as the failure reason code gives very limited This is important, as the failure reason code gives very limited
information for interpretation by the user of the Mobile Node. For information for interpretation by the user of the Mobile Node. For
example, a string like "registration failed : Prepaid Quota for the example, a string like "registration failed : Prepaid Quota for the
user is exhausted" can give a human readable description of the user is exhausted" can give a human readable description of the
result of Mobile IP registration. result of Mobile IP registration.
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 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
skipping to change at page 5, line 19 skipping to change at page 2, line 50
a skippable extension. a skippable extension.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Sub-Type | Text .... | Type | Length | Sub-Type | Text ....
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Type: Type:
To be assigned by IANA. An 8-bit identifier of the type mobility 145: An 8-bit identifier of the type mobility option.
option.
Length: Length:
8-bit unsigned integer. Length of the extension, in bytes, An 8-bit unsigned integer. Length of the extension, in bytes,
excluding the extension Type and the extension Length fields. excluding the extension Type and the extension Length fields.
This field MUST be set to 1 plus the total length of the Text This field MUST be set to 1 plus the total length of the Text
field. field.
Sub-Type: Sub-Type:
1: 1: Extension comes from the Home Agent
Extension comes from the Home Agent
2:
Extension comes from the Foreign Agent 2: Extension comes from the Foreign Agent
Text: Text:
The Text field is one or more octets, and its contents are The Text field is one or more octets, and its contents are
implementation dependent. It is intended to be human readable, implementation dependent. It is intended to be human readable,
and MUST NOT affect operation of the protocol. The message MUST and MUST NOT affect the operation of the protocol. The message
be in UTF-8 encoded ISO-10646 [RFC3629] characters. The number of MUST be in UTF-8 encoded ISO-10646 [RFC3629] characters. The
octets in the encoded representation of the message is always number of octets in the encoded representation of the message is
exactly the value of the Length field minus one. (In the UTF-8 always exactly the value of the Length field minus one. (The
case, the number of unicode characters represented by this octet number of unicode characters represented by this octet sequence
sequence may be smaller than the number of octets.) may be smaller than the number of octets.)
4. Operation and Use of the Message String Extension 4. Operation and Use of the Message String Extension
The Message String Extension is only valid for use within Mobile IPv4 The Message String Extension is only valid for use within Mobile IPv4
Registration Reply and Registration Revocation messages. The Message Registration Reply and Registration Revocation messages. The Message
String Extension is a skippable extension. Either the Home Agent or String Extension is a skippable extension. Either the Home Agent or
Foreign Agent or both can add the Message String Extension to Foreign Agent or both can add the Message String Extension to
registration messages. The usage of Text field of the Message String registration messages. The usage of Text field of the Message String
Extension is implementation dependent. For example, the message can Extension is implementation dependent. For example, the message can
be displayed on the Mobile Node's user interface, logged, or handled be displayed on the Mobile Node's user interface, logged, or handled
in an implementation dependent way, depending on the form of the in an implementation dependent way, depending on the form of the
Mobile Node. The Mobile Node may throttle how often the user is Mobile Node. The Mobile Node may throttle how often the user is
notified of the message. notified of the message.
As an example, the Home Agent may reject the first Registration As an example, the Home Agent may reject the first Registration
Request due to prepaid quota for the user is reached and may attach a Request because the prepaid quota for the user is reached and may
Message String Extension with the text "Prepaid quota reached. attach a Message String Extension with the text "Prepaid quota
Please contact www.paymore.example.com to update balance". The reached. Please contact www.paymore.example.com to update balance".
Mobile Node could display this on the user interface. As a response, The Mobile Node could display this on the user interface. As a
the user of the Mobile Node may take the required action to update response, the user of the Mobile Node may take the required action to
the prepaid account and retry the registration process. The Home update the prepaid account and retry the registration process. The
Agent may accept this Registration Request and attach a Message Home Agent may accept this Registration Request and attach a Message
String Extension with the text "Welcome to String Extension with the text "Welcome to
www.serviceprovider.example.com". The Mobile Node could display this www.serviceprovider.example.com". The Mobile Node could display this
on the user interface thus confirming successful creation of binding on the user interface, thus confirming a successful creation of
on Home Agent. binding on Home Agent.
In the case that the message is not originated by the Home Agent In the case that the message is not originated by the Home Agent
itself, but for instance is received from a RADIUS server [RFC2865], itself, but for instance, is received from a RADIUS server [RFC2865],
it could be received in some other encoding than UTF-8. If so, the it could be received in some other encoding than UTF-8. If so, the
Home Agent MUST convert the message to UTF-8 encoded ISO-10646 Home Agent MUST convert the message to UTF-8 encoded ISO-10646
[RFC3629] characters. [RFC3629] characters.
5. Security Considerations 5. Security Considerations
The Message String Extension can be added by the Home Agent or The Message String Extension can be added by the Home Agent or
Foreign Agent or both. The protection of the extension is based on Foreign Agent or both. The protection of the extension is based on
the ordering method specified for message authentication in RFC 3344 the ordering method specified for message authentication in RFC 3344
[RFC3344] and emphasized below. [RFC3344] and emphasized below.
skipping to change at page 8, line 7 skipping to change at page 4, line 40
Authentication Extension whenever present. However, since security Authentication Extension whenever present. However, since security
association between the Mobile Node and Foreign Agent is optional, it association between the Mobile Node and Foreign Agent is optional, it
is possible that the extension is not authenticated in this case. is possible that the extension is not authenticated in this case.
There is no confidentiality provided by the extension; the message is There is no confidentiality provided by the extension; the message is
transferred unencrypted, and if sensitive information is sent for transferred unencrypted, and if sensitive information is sent for
display purposes, it may need to be protected by other means. display purposes, it may need to be protected by other means.
6. IANA Considerations 6. IANA Considerations
This specification reserves one number for the Message String This specification reserves number 145 for the Message String
Extension in Section 3 from the space of numbers for skippable Extension in Section 3 from the space of numbers for skippable
mobility extensions (i.e., 128-255) defined for Mobile IPv4 [RFC3344] mobility extensions (i.e., 128-255) defined for Mobile IPv4 [RFC3344]
at http://www.iana.org/assignments/mobileip-numbers. at http://www.iana.org/assignments/mobileip-numbers.
The value 145 is suggested for this extension.
This specification also creates a new subtype space for the type This specification also creates a new subtype space for the type
number of this extension. The subtype values 1 and 2 are defined in number of this extension. The subtype values 1 and 2 are defined in
this specification. The subtype value 1 is reserved for use by Home this specification. The subtype value 1 is reserved for use by the
Agent and subtype value 2 is reserved for use by Foreign Agent. Home Agent and subtype value 2 is reserved for use by the Foreign
Similar to the procedures specified for Mobile IPv4 [RFC3344] number Agent. Similar to the procedures specified for Mobile IPv4 [RFC3344]
spaces, future allocations from this number space require expert number spaces, future allocations from this number space require
review [RFC2434]. expert review [RFC2434].
7. Acknowledgements 7. Acknowledgements
The authors would like to thank Avi Lior, Curtis Provost and Henrik The authors would like to thank Avi Lior, Curtis Provost, and Henrik
Levkowetz for their useful comments on an earlier version of this Levkowetz for their useful comments on an earlier version of this
document. Also, Russ Housley, Vidya Narayanan, Blake Ramsdell, Paul document. Also, Russ Housley, Vidya Narayanan, Blake Ramsdell, Paul
Hoffman, and Jeff Hutzelman provided justifications to mandate the Hoffman, and Jeff Hutzelman provided justifications to mandate the
need for only UTF-8 encoding in the message and solicited better need for only UTF-8 encoding in the message and solicited better
clarifications in the security consideration section. clarifications in the security considerations section.
8. Normative References 8. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434, IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998. October 1998.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)", "Remote Authentication Dial In User Service (RADIUS)", RFC
RFC 2865, June 2000. 2865, June 2000.
[RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344, [RFC3344] Perkins, C., Ed., "IP Mobility Support for IPv4", RFC
August 2002. 3344, August 2002.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003. 10646", STD 63, RFC 3629, November 2003.
Authors' Addresses Authors' Addresses
Venkateshwara Sastry Venkateshwara Sastry
Samsung Electronics Samsung Electronics
Bagmane Lake View, 'Block -B' 124/C 5th D Cross
66/1, Bagmane Tech Park, Byrasandra, Girinagar I Phase
C. V. Raman Nagar Bangalore 560085
Bangalpre 560093
India India
Phone: +91-80-41819999 Phone: +91-80-26725942
Email: venkat.s@samsung.com EMail: venkat.sastry@gmail.com
Kent Leung Kent Leung
Cisco Systems Cisco Systems
170 W. Tasman Drive 170 W. Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
US US
Phone: +1 408-526-5030 Phone: +1 408-526-5030
Email: kleung@cisco.com EMail: kleung@cisco.com
Alpesh Patel Alpesh Patel
Cisco Systems Cisco Systems
170 W. Tasman Drive 170 W. Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
US US
Phone: +1 408-853-9580 Phone: +1 408-853-9580
Email: alpesh@cisco.com EMail: alpesh@cisco.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
skipping to change at page 12, line 45 skipping to change at page 7, line 45
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Acknowledgment Acknowledgement
Funding for the RFC Editor function is provided by the IETF Funding for the RFC Editor function is currently provided by the
Administrative Support Activity (IASA). Internet Society.
 End of changes. 29 change blocks. 
90 lines changed or deleted 60 lines changed or added

This html diff was produced by rfcdiff 1.33. The latest version is available from http://tools.ietf.org/tools/rfcdiff/