Internet DRAFT - draft-ashir-simple-message-guideline
draft-ashir-simple-message-guideline
SIMPLE WG Ashir Ahmed
Internet Engineering Task Force Ginga Kawaguchi
Internet Draft Satoshi Tokuno
NTTCommunications Shinji Okumura
SoftFront
draft-ashir-simple-message-guideline-00.txt
February 9, 2004
Expires: August, 2004
A guideline on message headers and URI in SIP/SIMPLE framework
STATUS OF THIS MEMO
This document is an Internet-Draft and is in full conformance with
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
To view the list Internet-Draft Shadow Directories, see
http://www.ietf.org/shadow.html.
Abstract:
SUBSCRIBE, NOTIFY and PUBLISH methods in SIP are responsible for
carrying presence information to a target destination. Message headers
(Request-line, To, From, Contact etc.) indicate SIP entities that are
identified by a URI. This document clarifies the indication of the
message headers and provides a guideline on URI usage in the header
fields. The authors hope that this document will be useful for
SIP/SIMPLE implementers, interoperability testers, designers, and
protocol researchers.
1. Introduction
Presence information conveys the ability and willingness of a user to
communicate across a set of elements. RFC 2778 [ref] defines a model and
terminology for describing systems that provide presence information.
A.Ahmed, et. al. [Page 2]
Internet Draft URI Usage guideline Februrary 09, 2004
Presence service in that model is a system that accepts, stores, and
distributes presence information of a presentity (presence information
owner) to interested parties, called watchers. SUBSCRIBE [ref], NOTIFY
[ref] and PUBLISH[ref] have been introduced to carry these presence
information.
The message headers (Request-line, To, From and Contact etc) in these
methods indicate the elements involved in the transportation process.
Not all the headers are necessary to be understood by the elements. A
common understanding about the header fields and the URI scheme will be
useful for interoperability testing, SIP/SIMPLE implementations and in
designing protocols. This document clarifies what exactly the message
headers indicate and provides a guideline on URI usage.
A SIP/SIMPLE message flow example is also shown.
2. URIs in SIP/SIMPLE
This section describes the URIs used in SIP/SIMPLE framework and also
introduces the recommendations which URI should be used in representing
what resoruces or element.
URI: SIP-URI,SIPS-URI,Pres-URI and IM-URI
explanations about these URIs and their usage will be written later.
3. Methods, Message headers and URI usages
This section provides a brief description about the Methods used in
presence protocol, introduces the major header fields that are
responsible for carrying presence information.
3.2 Headers, indications and URI usage
Request-URI shows the URI that appears in the request-line of SIP
message. (To, From, Contact)-URI indecates the respective fields in SIP.
Some common tips:
-Only Request-URI is used to transfer presence information.
-SIP Proxies (or any other agents) MUST NOT use To: header to determine
message transfer location as this header will not be read by any other
SIP elements on the fly.
-Contact-URI is used only as a return-message recipient.
-From-URI MUST NOT be considered as any notification or replication entity.
Other fields are written below:
3.2.1 SUBSCRIBE:
Request-URI: indicates the presence resource. Usually this resource is
identified by a presence URI, which is in the form of
pres:resource@example.com. SIP or SIPS URI can also be used.
To-URI: indicates the logical recipient of the request (i.e. the pres
URI of the resource (e.g. pres:resource@example.com). SIP or SIPS URI
can also be used.
From-URI: indicates the subscriber itself. A SIP or SIPS URI can be used
to identify the subscriber (e.g. sip:user@example.com).
Contact-URI: indicates the subscriber's contact address where the
subscriber can be reached at (e.g. sip:user@watcherhost.example.com).
A.Ahmed, et. al. [Page 3]
Internet Draft URI Usage guideline Februrary 09, 2004
3.2.2 NOTIFY:
NOTIFY is a response to the SUBSCRIBE request. Some headers are copied
from the SUBSRIBE request to identify the subscriber and the
intermediate entities, if any.
Request-URI: indicates the subscriber of the request and is identified
by the Contact-URI of SUBSCRIBE request (e.g.
sip:user@watcherhost.example.com).
To-URI: indicates the subscriber's logical identity and is identified by
the From-URI of SUBSCRIBE request (e.g. sip:user@example.com)
From-URI : indicates the notifier or the To-URI of SUBSCRIBE request
(e.g. pres:resource@example.com)
Contact-URI : indicates the Contact address of the presence server (e.g.
sip.server.example.com).
3.2.3 PUBLISH:
Request-URI: indicates a presence resource to be published. Usually a
pres-URI (e.g. pres:resource@example.com) of the presentity is used for
identification.
To-URI: indicates the presence resource. Usually a pres-URI is used for
identification.
From-URI: indicates the presentity. A SIP or SIPS URI is used.
Contact: optional
4. Message flow example
4.1 A simple example
This example contains the minimum set of elements. Description of these
elements are defined in RFC 2778 [ref] and explained in several IETF drafts.
Element Display Name URI/FQDN IP Address
PUA bobüfs PUA sip:bob@example.com 10.0.0.2
pua.example.com
PA sip:pa@example.com 10.0.0.3
A.Ahmed, et. al. [Page 4]
Internet Draft URI Usage guideline Februrary 09, 2004
<pres:bob@example.com>
pa.example.com
Watcher Alice sip:alice@example.com 10.0.0.1
wua.example.com
Proxy sip:proxy.example.com 10.0.0.4
proxy.example.com
This message flow illustrates how a PUA uploads presence information to the
presence server (PA) by using PUBLISH; a WATCHER (Alice) sends a SUBSCRIBE
request to know Bobüfs presence state. This flow assumes that the watcher
and the PUA have previously been authorized to upload and subscribe to this
resource at the server. This is also assumed that all the messages go
through the proxy.
PUA PA PROXY WATCHER
(EPA) (ESC) (REGISTRAR)
| | | |
| |--R1: REGISTER-->| |
| | | |
| |<-R2: 200 OK-----| |
| | | |
| | |<---M1: SUBSCRIBE---|
| |<-M2: SUBSCRIBE--| |
| | | |
| |--M3: 200 OK---->| |
| | |----M4: 200 OK----->|
| |--M5: NOTIFY---->| |
| | |----M6: NOTIFY----->|
| | | |
| | |<---M7: 200 OK------|
| |<-M8: 200 OK-----| |
| | | |
| | | |
| | | |
|--M9: PUBLISH->| | |
| | | |
| |<-M10: PUBLISH---| |
| | | |
| |--M11: 200 OK--->| |
| | | |
|<-M12 200 OK---| | |
| | | |
| |--M13: NOTIFY--->| |
A.Ahmed, et. al. [Page 5]
Internet Draft URI Usage guideline Februrary 09, 2004
| | |----M14: NOTIFY---->|
| | | |
| | |<---M15: 200 OK-----|
| |<-M16: 200 OK----| |
| | | |
It is assumed that the AoR of bob as pres:bob@example.com in registered
in the proxy.
R1: REGISTER
REGISTER sip:example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa0
Max-Forwards: 70
To: <pres:bob@example.com>
From: <sip:bob@example.com>;tag=456248
Call-ID: 843817637684230@pa.example.com
CSeq: 1 REGISTER
Contact: <pres:bob@pa.example.com>
Expires: 7200
Content-Length: 0
R2: 200 OK
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa0
To: <pres:bob@example.com>;tag=2493k59kd
From: <sip:bob@example.com>;tag=456248
Call-ID: 843817637684230@pa.example.com
CSeq: 1 REGISTER
Contact: <pres:bob@pa.example.com>
Expires: 7200
Content-Length: 0
M1: SUBSCRIBE
SUBSCRIBE pres:bob@example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.1:5060;branch=z9hG4bKwatcher1
To: <pres:bob@example.com>
From: <sip:alice@example.com>;tag=123456
Call-ID: 12345678@wua.example.com
CSeq: 1 SUBSCRIBE
Max-Forwards: 70
Expires: 3600
Event: presence
Contact: <sip:alice@wua.example.com>
Content-Length: 0
A.Ahmed, et. al. [Page 6]
Internet Draft URI Usage guideline Februrary 09, 2004
M2: SUBSCRIBE
SUBSCRIBE pres:bob@pa.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy1
Via: SIP/2.0/UDP 10.0.0.1:5060;branch=z9hG4bKwatcher1
To: <pres:bob@example.com>
From: <sip:alice@example.com>;tag=123456
Call-ID: 12345678@wua.example.com
CSeq: 1 SUBSCRIBE
Max-Forwards: 69
Expires: 3600
Event: presence
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:alice@wua.example.com>
Content-Length: 0
M3: 200 OK
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy1
Via: SIP/2.0/UDP 10.0.0.1:5060;branch=z9hG4bKwatcher1
To: <pres:bob@example.com>;tag=234567
From: <sip:alice@example.com>;tag=123456
Call-ID: 12345678@wua.example.com
CSeq: 1 SUBSCRIBE
Expires: 3600
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Content-Length: 0
M4: 200 OK
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.0.0.1:5060;branch=z9hG4bKwatcher1
To: <pres:bob@example.com>;tag=234567
From: <sip:alice@example.com>;tag=123456
Call-ID: 12345678@wua.example.com
CSeq: 1 SUBSCRIBE
Expires: 3600
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Content-Length: 0
M5: NOTIFY
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa1
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 1 NOTIFY
Max-Forwards: 70
A.Ahmed, et. al. [Page 7]
Internet Draft URI Usage guideline Februrary 09, 2004
Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Event: presence
Subscription-State: active; expires=3599
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
<tuple id="mobile-phone">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T16:49:29Z</timestamp>
</tuple>
<tuple id="desktop">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T12:21:29Z</timestamp>
</tuple>
</presence>
M6: NOTIFY
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy2
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa1
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 1 NOTIFY
Max-Forwards: 69
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Event: presence
Subscription-State: active; expires=3599
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
<tuple id="mobile-phone">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T16:49:29Z</timestamp>
A.Ahmed, et. al. [Page 8]
Internet Draft URI Usage guideline Februrary 09, 2004
</tuple>
<tuple id="desktop">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T12:21:29Z</timestamp>
</tuple>
</presence>
M7: 200 OK
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy2
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa1
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 1 NOTIFY
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:alice@wua.example.com>
Content-Length: 0
M8: 200 OK
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa1
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 1 NOTIFY
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:alice@wua.example.com>
Content-Length: 0
M9: PUBLISH
PUBLISH pres:bob@example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bKpua1
To: <pres:bob@example.com>
From: <sip:bob@example.com>;tag=1234wxyz
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
Max-Forwards: 70
Expires: 3600
Event: presence
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
A.Ahmed, et. al. [Page 9]
Internet Draft URI Usage guideline Februrary 09, 2004
<tuple id="mobile-phone">
<status>
<basic>closed</basic>
</status>
<timestamp>2003-02-01T17:00:19Z</timestamp>
</tuple>
</presence>
M10: PUBLISH
PUBLISH pres:bob@pa.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy3
Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bKpua1
To: <pres:bob@example.com>
From: <sip:bob@example.com>;tag=1234wxyz
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
Max-Forwards: 69
Expires: 3600
Event: presence
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
<tuple id="mobile-phone">
<status>
<basic>closed</basic>
</status>
<timestamp>2003-02-01T17:00:19Z</timestamp>
</tuple>
</presence>
M11: 200 OK
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy3
Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bKpua1
To: <pres:bob@example.com>;tag=abcd5678
From: <sip:bob@example.com>;tag=1234wxyz
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
Content-Length: 0
M12: 200 OK
SIP/2.0 200 OK
Via: SIP/2.0/UDP 10.0.0.2:5060;branch=z9hG4bKpua1
To: <pres:bob@example.com>;tag=abcd5678
From: <sip:bob@example.com>;tag=1234wxyz
A.Ahmed, et. al. [Page 10]
Internet Draft URI Usage guideline Februrary 09, 2004
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
Content-Length: 0
M13: NOTIFY
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa2
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 2 NOTIFY
Max-Forwards: 70
Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Event: presence
Subscription-State: active; expires=3400
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
<tuple id="mobile-phone">
<status>
<basic>closed</basic>
</status>
<timestamp>2003-02-01T17:00:19Z</timestamp>
</tuple>
<tuple id="desktop">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T12:21:29Z</timestamp>
</tuple>
</presence>
M14: NOTIFY
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy4
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa2
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 2 NOTIFY
Max-Forwards: 69
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:pa.example.com>
Event: presence
A.Ahmed, et. al. [Page 11]
Internet Draft URI Usage guideline Februrary 09, 2004
Subscription-State: active; expires=3400
Content-Type: application/pidf+xml
Content-Length: ...
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
entity="pres:bob@example.com">
<tuple id="mobile-phone">
<status>
<basic>closed</basic>
</status>
<timestamp>2003-02-01T17:00:19Z</timestamp>
</tuple>
<tuple id="desktop">
<status>
<basic>open</basic>
</status>
<timestamp>2003-02-01T12:21:29Z</timestamp>
</tuple>
</presence>
M15: 200 OK
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.4:5060;branch=z9hG4bKproxy4
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa2
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 2 NOTIFY
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:alice@wua.example.com>
Content-Length: 0
M16: 200 OK
NOTIFY sip:alice@wua.example.com SIP/2.0
Via: SIP/2.0/UDP 10.0.0.3:5060;branch=z9hG4bKpa2
To: <sip:alice@example.com>;tag=123456
From: <pres:bob@example.com>;tag=234567
Call-ID: 12345678@wua.example.com
CSeq: 2 NOTIFY
Record-Route: <sip:proxy.example.com; lr>
Contact: <sip:alice@wua.example.com>
Content-Length: 0
A.Ahmed, et. al. [Page 12]
Internet Draft URI Usage guideline Februrary 09, 2004
4.2 An example with presence related functions
TBD. An example with Filter function, RLS etc will be described.
5. Security Consideration
6. References
6.1 Normative Reference
[1] Roach, A., "Session Initiation Protocol (SIP)-Specific Event
Notification", RFC 3265, June 2002.
[2] Rosenberg, J., "A Presence Event Package for the Session
Initiation Protocol (SIP)", draft-ietf-simple-presence-10 (work
in progress), January 2003.
[3] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP:
Session Initiation Protocol", RFC 3261, June 2002.
6.2 Informative References
[4] Campbell, B., "SIMPLE Presence Publication Requirements",
draft-ietf-simple-publish-reqs-00 (work in progress), February
2003.
[5] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9,
RFC 959, October 1985.
[6] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., Masinter, L.,
Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol --
HTTP/1.1", RFC 2616, June 1999.
[7] Rosenberg, J., "A Presence Event Package for the Session
Initiation Protocol (SIP)", draft-ietf-simple-presence-10 (work
in progress), January 2003.
[8] Sugano, H. and S. Fujimoto, "Presence Information Data Format
(PIDF)", draft-ietf-impp-cpim-pidf-08 (work in progress), May
2003.
2.1 Methods:SUBSCRIBE:NOTIFY:PUBLISH:
A.Ahmed, et. al. [Page 13]
Internet Draft URI Usage guideline Februrary 09, 2004
7. Authors' Addresses
Ashir Ahmed
NTTCommunications Inc.
3-20-2 Nishi-Shinjuku
Shinjuku-ku, Tokyo 163-1421
JAPAN
Phone: +81 3 6800 3029
EMail: a.ahmed@ntt.com
Ginga Kawaguti
NTTCommunications Inc.
3-20-2 Nishi-Shinjuku
Shinjuku-ku, Tokyo 163-1421
JAPAN
Phone: +81 3 6800 3032
EMail: g.kawaguti@ntt.com
Satoshi Tokuno
NTTCommunications Inc.
3-20-2 Nishi-Shinjuku
Shinjuku-ku, Tokyo 163-1421
JAPAN
Phone: +81 3 6800 3031
EMail: s.tokuno@ntt.com
Shinji Okumura
SoftFront
3F Sapporo IT Front Bldg.,
28-196, Kita-9, Nishi-15, Chuo-ku, Sapporo 060-0009
JAPAN
Tel: +81-11-623-1001
EMail:shin@softfront.co.jp
8. Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
intellectual property 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; neither does it represent that it
A.Ahmed, et. al. [Page 14]
Internet Draft URI Usage guideline Februrary 09, 2004
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication 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 implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
9. Full Copyright Statement
Copyright (C) The Internet Society (2004). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS 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.
10. Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
