Network Working Group P. Saint-Andre
Internet-Draft Jabber Software Foundation
Expires: August 8, 2004 A. Houri
IBM
J. Hildebrand
Jabber, Inc.
February 8, 2004
Interoperability between the Extensible Messaging and Presence
Protocol (XMPP) and SIP for Instant Messaging and Presence Leveraging
Extensions (SIMPLE)
draft-saintandre-xmpp-simple-00
Status of this Memo
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Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
This document defines a bi-directional protocol mapping for use by
gateways that enable the exchange of instant messages and presence
information between systems that implement the Extensible Messaging
and Presence Protocol (XMPP) and those that implement SIP for Instant
Messaging and Presence Leveraging Extensions (SIMPLE).
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 XMPP to SIMPLE . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 SIMPLE to XMPP . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Instant Messages . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 XMPP to SIMPLE . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 SIMPLE to XMPP . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Presence Information . . . . . . . . . . . . . . . . . . . . . 10
4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2 XMPP to SIMPLE . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3 SIMPLE to XMPP . . . . . . . . . . . . . . . . . . . . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 14
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
Normative References . . . . . . . . . . . . . . . . . . . . . 14
Informative References . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 16
Intellectual Property and Copyright Statements . . . . . . . . 17
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1. Introduction
In order to help ensure interoperability between instant messaging
and presence systems that conform to the requirements of RFC 2779
[IMP-REQS], it is important to clearly define mappings between such
protocols. Within the IETF, work has proceeded on two such
protocols: SIP for Instant Messaging and Presence Leveraging
Extensions (SIMPLE), which consists of extensions to the Session
Initiation Protocol ([SIP]), and the Extensible Messaging and
Presence Protocol (XMPP), which consists of a formalization of the
core XML streaming protocols developed originally by the Jabber
open-source community. One approach to helping ensure
interoperability between such protocols is to map each protocol to
the abstract semantics described in [CPIM] and [CPP]; that is the
approach taken by [SIMPLE-CPIM] and [XMPP-CPIM]. Another approach is
that taken by [DRAFT-UMPP]. The approach taken in this document is
to directly map semantics from one protocol to another (i.e., from
SIMPLE to XMPP and vice-versa), mainly for use by gateways between
systems that implement one or the other of these protocols. (These
approaches describe concepts that are complementary in many ways, and
a future draft may provide a more substantive merger between them.)
The mappings specified in this document cover three main areas:
o Mapping of addresses
o Mapping of instant messages
o Mapping of presence information
It is important to note that an underlying architectural assumption
for this document is that the mapping between protocols will most
likely occur by means of a gateway between an XMPP network and a
SIMPLE network. Such a gateway is a dedicated translator between the
XMPP and SIMPLE protocols, which naturally may be co-resident with an
XMPP server or a SIMPLE server. Although such a gateway could use
the [CPIM] and [CPP] specifications to define the common formats into
which the protocols are translated for purposes of interworking (as
specified in [SIMPLE-CPIM] and [XMPP-CPIM].), this document assumes
that a SIMPLE-XMPP gateway will translate directly from one protocol
to the other.
1.1 Terminology
The capitalized 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 [TERMS].
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2. Addresses
2.1 Overview
The address formats used to identify XMPP entities are different from
those used to identify SIP/SIMPLE entities. The XMPP address format
is specified in [XMPP-CORE]; as specified in [XMPP-IM], instant
messaging and presence applications of XMPP MUST also support 'im:'
and 'pres:' URIs as specified in [CPIM] and [CPP] respectively. The
SIP/SIMPLE address format for instant messaging is specified in
[SIP-IM]; it may use either 'sip:' or 'sips:' URIs as specified in
[SIP] or an 'im:' URI as specified in [CPIM]. The SIP/SIMPLE address
format for presence is specified in [SIP-PRES]; it may use either
'sip:' or 'sips:' URIs as specified in [SIP] or a 'pres:' URI as
specified in [CPP].
In this document we describe mappings for addresses of the form
<user@domain> only, ignoring any protocol-specific extensions such as
XMPP resource identifiers or SIP telephone numbers and passwords.
However, we have ruled the mapping of domain names as out of scope
for the initial version of this document, since it is a matter for
the Domain Name System and the translation of fully internationalized
domain names (which the SIP address format does not allow, but which
the XMPP address format does allow via [IDNA]) into
non-internationalized domain names. Therefore in the following
sections we treat local-part addresses only (these are called
variously "usernames", "instant inboxes", "presentities", and "node
identifiers" in the protocols at issue).
The sip:/sips:, im:/pres:, and XMPP address schemes allow different
sets of characters. In some cases, characters allowed in one scheme
are disallowed in others; these characters must be mapped
appropriately in order to ensure interoperable communications across
systems. The table below summarizes our findings regarding the
complement of allowable US-ASCII characters in each addressing scheme
when compared individually to the other schemes.
Table 1: Partial complements of allowable US-ASCII characters
+----------+----------+-----------+-------+
| | SIP/SIPS | IM/PRES | XMPP |
+----------+----------+-----------+-------+
| SIP/SIPS | N/A | (),; | &'/ |
+----------+----------+-----------+-------+
| IM/PRES | #%^`{|} | N/A | &'/ |
+----------+----------+-----------+-------+
| XMPP | none | none | N/A |
+----------+----------+-----------+-------+
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Note: Each cell shows US-ASCII characters that are disallowed in the
column protocol but allowed in the row protocol; e.g., the last cell
of the third row shows that the characters &'/ are allowed in sip:/
sips: URIs but disallowed in XMPP addresses.
The table below is another way of looking at the same issue, since it
shows the intersection of allowable US-ASCII characters in each
addressing scheme when compared individually to the other schemes.
Table 2: Partial intersections of allowable US-ASCII characters
+-------------------+------------------+----------------------+
| SIP/SIPS & XMPP | IM/PRES & XMPP | SIP/SIPS & IM/PRES |
+-------------------+------------------+----------------------+
| a-z A-Z 0-9 | a-z A-Z 0-9 | a-z A-Z 0-9 |
| !$()*+,-.;=?_~ | !#$%*+-.=?^_` | !$*+-.=?_~ |
| %hexhex | {|}~ | |
+-------------------+------------------+----------------------+
Therefore the following US-ASCII characters are allowed in all three
addressing schemes (i.e., the intersection of all three sets of
allowable characters):
a-z A-Z 0-9 ! $ * + - . = ?
In addition to the US-ASCII characters described above, many
non-US-ASCII (specifically, UTF-8) characters are allowed in XMPP
addresses but not allowed in sip:/sips: or im:/pres: URIs, since XMPP
allows internationalized local-part addresses. A straightforward
mapping of these characters to US-ASCII characters is provided in
Section 2.2.5 of [URL-GUIDE], namely to encode unsafe octets using
the %hexhex encoding.
2.2 XMPP to SIMPLE
The following is a high-level algorithm for mapping an XMPP address
to a sip:, sips:, im:, or pres: URI:
1. Split XMPP address into node identifier (local-part; mapping
described in remaining steps), domain identifier (hostname;
mapping is out of scope), and resource identifier (specifier for
particular device or connection; discard this for cross-system
interoperability)
2. Apply Nodeprep profile of [STRINGPREP] (as specified in
[XMPP-CORE]) for canonicalization (OPTIONAL)
3. Translate #26; to &, #27; to ', and #2f; to / respectively
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4. For each byte, if the byte is not in the set -A-Za-z0-9!$*.?_~+=
then change to %hexhex
5. Combine resulting local-part with mapped hostname to form
local@domain address
6. Prepend with 'im:' scheme (for XMPP <message/> stanzas) or
'pres:' scheme (for XMPP <presence/> stanzas) if foreign domain
supports these (discovered via [SRV] lookup as specified in
[XMPP-IM]), else prepend with 'sip:' or 'sips:' scheme according
to local service policy
2.3 SIMPLE to XMPP
The following is a high-level algorithm for mapping a sip:, sips:,
im:, or pres: URI to an XMPP address:
1. Remove URI scheme
2. Split at the first '@' character into local-part and hostname
(mapping the latter is out of scope)
3. Translate %hexhex to equivalent octets
4. Treat result as a UTF-8 string
5. Translate & to #26;, ' to #27;, and / to @2f respectively
6. Apply Nodeprep profile of [STRINGPREP] (as specified in
[XMPP-CORE]) for canonicalization (OPTIONAL)
7. Recombine local-part with mapped hostname to form local@domain
address
3. Instant Messages
3.1 Overview
Both XMPP and SIMPLE systems enable entities (often but not
necessarily human users) to send "instant messages" to other
entities. The term "instant message" usually refers to messages sent
between two entities for delivery in close to real time (rather than
messages that are stored and forwarded to the intended recipient upon
request). Generally there are three kinds of instant message:
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o Single messages, which are sent from the sender to the recipient
outside the context of any one-to-one chat session or multi-user
text conference.
o Chat messages, which are sent from the sender to the recipient in
the context of a "message session" between the two entities.
o Groupchat messages, which are sent from a sender to multiple
recipients in the context of a text conference (along the lines of
[IRC]).
This document addresses single messages only, since they form the
"lowest common denominator" for instant messaging on the Internet.
It is likely that future versions of this document will address chat
messages as well, especially once the SIMPLE WG completes its work on
one-to-one message sessions (a likely candidate for finalization is
[SIMPLE-MSRP]).
Instant messaging using XMPP message stanzas of type "normal" is
specified in [XMPP-IM]. SIP/SIMPLE instant messaging using SIP
requests of type MESSAGE (often called "pager-model" messaging) is
specified in [SIP-IM].
As described in [XMPP-IM], a single instant message is an XML
<message/> stanza of type "normal" sent over an XML stream (since
"normal" is the default for the 'type' attribute of the <message/>
stanza, the attribute is often omitted). In this document we will
assume that such a message is sent from an XMPP client to an XMPP
server over an XML stream negotiated between the client and the
server, and that the client is controlled by a human user (this is a
simplifying assumption introduced for explanatory purposes only; the
XMPP sender could be a bot-controlled client, a component such as a
workflow application, a server, etc.). Continuing the tradition of
Shakespeare examples in XMPP documentation, we will say that the XMPP
user has an XMPP address of <juliet@example.com>.
As described in [SIP-IM], a single instant message is a SIP MESSAGE
request sent from a SIP user agent to an intended recipient who is
most generally referenced by an Instant Message URI of the form
"im:user@domain" but who may be referenced by a SIP or SIPS URI of
the form "sip:user@domain" or "sips:user@domain". Here again we
introduce the simplifying assumption that the user agent is
controlled by a human user, whom we shall dub <romeo@example.net>.
3.2 XMPP to SIMPLE
When Juliet wants to send an instant message to Romeo, she interacts
with her XMPP client, which generates an XMPP <message/> stanza. The
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syntax of the <message/> stanza, including required and optional
elements and attributes, is defined in [XMPP-IM]. The following is
an example of such a stanza:
Example: An XMPP message stanza:
<message from='juliet@example.com/balcony'
to='romeo@example.net'>
<body>Art thou not Romeo, and a Montague?</body>
</message>
Upon receiving such a stanza, the XMPP server to which Juliet has
connected either delivers it to a local recipient (if the hostname in
the 'to' attribute matches one of the hostnames serviced by the XMPP
server) or attempts to route it to the foreign domain that services
the hostname in the 'to' attribute. Naturally, in this document we
assume that the hostname in the 'to' attribute is a SIMPLE instant
messaging service hosted by a separate server. As specified in
[XMPP-IM], the XMPP server needs to determine the identity of the
foreign domain, which it does by performing one or more [SRV]
lookups. For message stanzas, the order of lookups recommended by
[XMPP-IM] is to first try the "_xmpp-server" service as specified in
[XMPP-CORE] and to then try the "_im" service as specified in
[IMP-SRV]. Here we assume that the first lookup will fail but that
the second lookup will succeed and return a resolution
"_im._simple.example.net.", since we have already assumed that the
example.net hostname is running a SIMPLE instant messaging service.
(Note: The XMPP server may have previously determined that the
foreign domain is a SIMPLE server, in which case it would not need to
perform the SRV lookups; the caching of such information is a matter
of implementation and local service policy, and is therefore out of
scope for this document.)
Once the XMPP server has determined that the foreign domain is
serviced by a SIMPLE server, it must determine how to proceed. We
here assume that the XMPP server contains or has available to it an
XMPP-SIMPLE gateway. The XMPP server would then deliver the message
stanza to the XMPP-SIMPLE gateway.
The XMPP-SIMPLE gateway is then responsible for translating the XMPP
message stanza into a SIP MESSAGE request from the XMPP user to the
SIMPLE user:
Example: A SIP MESSAGE request:
MESSAGE sip:romeo@example.net SIP/2.0
Via: SIP/2.0/TCP julietpc.example.com;branch=z9hG4bK776sgdkse
Max-Forwards: 70
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From: sip:juliet@example.com;tag=49583
To: sip:romeo@example.net
Call-ID: Hr0zny9l3@example.com
CSeq: 1 MESSAGE
Content-Type: text/plain
Content-Length: 37
Art thou not Romeo, and a Montague?
Detailed recommendations regarding mapping or generation of SIP
MESSAGE header fields by an XMPP-SIMPLE gateway will be provided in a
future revision of this document.
3.3 SIMPLE to XMPP
When Romeo wants to send an instant message to Juliet, he interacts
with his SIP user agent, which generates a SIP MESSAGE request. The
syntax of the MESSAGE request is defined in [SIP-IM]. The following
is an example of such a request:
Example: Another SIP MESSAGE request:
MESSAGE sip:juliet@example.com SIP/2.0
Via: SIP/2.0/TCP romeopc.example.com;branch=eskdgs677Kb4Ghz9
Max-Forwards: 70
From: sip:romeo@example.net;tag=38594
To: sip:juliet@example.com
Call-ID: M4spr4vdu@example.net
CSeq: 1 MESSAGE
Content-Type: text/plain
Content-Length: 26
Neither, fair saint, if either thee dislike.
Upon receiving such a request, a SIMPLE-XMPP gateway is responsible
for translating it into an XMPP message stanza from the SIP user to
the XMPP user:
Example: Another XMPP message stanza:
<message from='romeo@example.net'
to='juliet@example.com'>
<body>Neither, fair saint, if either thee dislike.</body>
</message>
Detailed recommendations regarding mapping or generation of XMPP
message stanza elements and attributes by a SIMPLE-XMPP gateway will
be provided in a future revision of this document.
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4. Presence Information
4.1 Overview
Both XMPP and SIMPLE systems enable entities (often but not
necessarily human users) to send presence to other entities. At a
minimum, the term "presence" refers to information about an entity's
availability for communication on a network (on/off), often
supplemented by information that further specifies the entity's
communications context (e.g., "do not disturb"). Some systems and
protocols extend this notion even further and refer to any relatively
ephemeral information about an entity as a kind of presence;
categories of such "extended presence" include geographical location
(e.g., GPS coordinates), user mood (e.g., grumpy), user activity
(e.g., walking), and ambient environment (e.g., noisy). In this
document, we focus on the "least common denominator" of network
availability only, although future revisions of this document may
address broader notions of presence. In addition, we address
presence notifications only, not presence subscriptions.
Presence using XMPP presence stanzas of type "available" or
"unavailable" is specified in [XMPP-IM]. SIP/SIMPLE presence using a
SIP event package for presence is specified in [SIP-PRES].
As described in [XMPP-IM], presence information about an entity is
communicated by means of an XML <presence/> stanza sent over an XML
stream. In this document we will assume that such a presence stanza
is sent from an XMPP client to an XMPP server over an XML stream
negotiated between the client and the server, and that the client is
controlled by a human user (again, this is a simplifying assumption
introduced for explanatory purposes only). In general, XMPP presence
is sent by the user to the user's server and then broadcasted to all
entities who are subscribed to the user's presence information.
As described in [SIP-PRES], presence information about an entity is
communicated by means of a SIP NOTIFY event sent from a SIP user
agent to an intended recipient who is most generally referenced by an
Instant Message URI of the form "pres:user@domain" but who may be
referenced by a SIP or SIPS URI of the form "sip:user@domain" or
"sips:user@domain". Here again we introduce the simplifying
assumption that the user agent is controlled by a human user.
4.2 XMPP to SIMPLE
When Juliet interacts with her XMPP client to modify her presence
information (or when her client automatically updates her presence
information, e.g. via an "auto-away" feature), her client generates
an XMPP <presence/> stanza. The syntax of the <presence/> stanza,
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including required and optional elements and attributes, is defined
in [XMPP-IM]. The following is an example of such a stanza:
Example: An XMPP presence stanza:
<presence from='juliet@example.com/balcony'/>
Upon receiving such a stanza, the XMPP server to which Juliet has
connected broadcasts it to all subscribers who are authorized to
receive presence notifications from Juliet. For each subscriber,
broadcasting the presence notification involves either delivering it
to a local recipient (if the hostname in the subscriber's address
matches one of the hostnames serviced by the XMPP server) or
attempting to route it to the foreign domain that services the
hostname in the subscriber's address. Naturally, in this document we
assume that the hostname is a SIMPLE presence service hosted by a
separate server. As specified in [XMPP-IM], the XMPP server needs to
determine the identity of the foreign domain, which it does by
performing one or more [SRV] lookups. For presence stanzas, the
order of lookups recommended by [XMPP-IM] is to first try the
"_xmpp-server" service as specified in [XMPP-CORE] and to then try
the "_pres" service as specified in [IMP-SRV]. Here we assume that
the first lookup will fail but that the second lookup will succeed
and return a resolution "_pres._simple.example.net.", since we have
already assumed that the example.net hostname is running a SIMPLE
presence service. (Note: The XMPP server may have previously
determined that the foreign domain is a SIMPLE server, in which case
it would not need to perform the SRV lookups; the caching of such
information is a matter of implementation and local service policy,
and is therefore out of scope for this document.)
Once the XMPP server has determined that the foreign domain is
serviced by a SIMPLE server, it must determine how to proceed. We
here assume that the XMPP server contains or has available to it an
XMPP-SIMPLE gateway. The XMPP server would then deliver the presence
stanza to the XMPP-SIMPLE gateway.
The XMPP-SIMPLE gateway is then responsible for translating the XMPP
presence stanza into a SIP NOTIFY request and included PIDF document
from the XMPP user to the SIMPLE user:
Example: A SIP NOTIFY request:
NOTIFY sip:romeo@example.net SIP/2.0
Via: SIP/2.0/TCP simple.example.net;branch=z9hG4bKna998sk
From: <sip:juliet@example.com>;tag=ffd2
To: <sip:romeo@example.net>;tag=xfg9
Call-ID: j4s0h4vny@example.com
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Event: presence
Subscription-State: active;expires=599
Max-Forwards: 70
CSeq: 8775 NOTIFY
Contact: sip:simple.example.net
Content-Type: application/cpim-pidf+xml
Content-Length: 192
<?xml version='1.0' encoding='UTF-8'?>
<presence xmlns='urn:ietf:params:xml:ns:pidf'
entity='pres:juliet@example.com'>
<tuple id='balcony'>
<status>
<basic>open</basic>
</status>
</tuple>
</presence>
Detailed recommendations regarding mapping or generation of SIP
NOTIFY header fields and PIDF document elements and attributes by an
XMPP-SIMPLE gateway will be provided in a future revision of this
document.
4.3 SIMPLE to XMPP
When Romeo changes his presence, his SIP user agent generates a SIP
NOTIFY request. The syntax of the NOTIFY request is defined in
[SIP-PRES]. The following is an example of such a request:
Example: Another SIP NOTIFY request:
NOTIFY sip:juliet@example.com SIP/2.0
Via: SIP/2.0/TCP simple.example.net;branch=z9hG4bKna998sk
From: <sip:romeo@example.net>;tag=ffd2
To: <sip:juliet@example.com>;tag=xfg9
Call-ID: j0sj4sv1m@example.net
Event: presence
Subscription-State: active;expires=599
Max-Forwards: 70
CSeq: 8775 NOTIFY
Contact: sip:simple.example.net
Content-Type: application/cpim-pidf+xml
Content-Length: 193
<?xml version='1.0' encoding='UTF-8'?>
<presence xmlns='urn:ietf:params:xml:ns:pidf'
entity='pres:romeo@example.net'>
<tuple id='orchard'>
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<status>
<basic>closed</basic>
</status>
</tuple>
</presence>
Upon receiving such a request, a SIMPLE-XMPP gateway is responsible
for translating it into an XMPP presence stanza from the SIP user to
the XMPP user:
Example: Another XMPP presence stanza:
<presence from='romeo@example.net'
to='juliet@example.com/balcony'
type='unavailable'/>
Detailed recommendations regarding mapping or generation of XMPP
presnce stanza elements and attributes by a SIMPLE-XMPP gateway will
be provided in a future revision of this document.
5. IANA Considerations
This document requires no action on the part of the IANA.
6. Security Considerations
Detailed security considerations for instant messaging and presence
protocols are given in [IMP-REQS], specifically in Sections 5.1
through 5.4. Detailed security considerations for XMPP are given in
XMPP Core [XMPP-CORE]. Detailed security considerations for SIMPLE
messaging are given in [SIP-IM] and for SIMPLE presence are given in
[SIP-PRES] (see also the security considerations for the Session
Initiation Protocol given in [SIP]).
This document specifies methods for exchanging instant messages and
presence information through a gateway that translates between SIMPLE
and XMPP. Such a gateway MUST be compliant with the minimum security
requirements of the instant messaging and presence protocols for
which it translates (i.e., SIMPLE and XMPP). The introduction of
gateways to the security model of instant messaging and presence
specified in [IMP-REQS] introduces some new risks. In particular,
end-to-end security properties (especially confidentiality and
integrity) between instant messaging and presence user agents that
interface through a SIMPLE-XMPP gateway can be provided only if
common formats are supported. Specification of those common formats
is out of scope for this document, although it is recommended to use
[MSGFMT] for instant messages and [PIDF] for presence.
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7. Open Issues
This document has made certain simplifying assumptions and has ruled
a number of problematic issues out of scope for now. However, future
revisions of this document will attempt to address these issues,
which include:
o Internationalized domain names
o Chat messages / instant messaging sessions
o Presence subscriptions
o More detailed syntax mappings
o Error handling and specific conditions
o Address resolution (including SRV lookups) from SIMPLE to XMPP
o End-to-end object encryption using common formats (e.g., PIDF for
presence)
o Ensuring end-to-end channel encryption using TLS
o Blocking communications (whitelisting/blacklisting) across systems
8. Acknowledgements
The authors wish to thank Nathaniel Borenstein and Rohan Mahy for
suggestions and encouragement.
Normative References
[IMP-SRV] Peterson, J., "Address Resolution for Instant Messaging
and Presence", draft-ietf-impp-srv-04 (work in progress),
October 2003.
[PIDF] Fujimoto, S., Sugano, H., Klyne, G., Bateman, A., Carr, W.
and J. Peterson, "CPIM Presence Information Data Format",
draft-ietf-impp-cpim-pidf-08 (work in progress), May 2003.
[SIP] 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.
[SIP-IM] Campbell, B., Rosenberg, J., Schulzrinne, H., Huitema, C.
and D. Gurle, "Session Initiation Protocol (SIP) Extension
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Internet-Draft XMPP SIMPLE Interop February 2004
for Instant Messaging", RFC 3428, December 2002.
[SIP-PRES]
Rosenberg, J., "A Presence Event Package for the Session
Initiation Protocol (SIP)", draft-ietf-simple-presence-10
(work in progress), January 2003.
[SRV] Gulbrandsen, A., Vixie, P. and L. Esibov, "A DNS RR for
specifying the location of services (DNS SRV)", RFC 2782,
February 2000.
[STRINGPREP]
Hoffman, P. and M. Blanchet, "Preparation of
Internationalized Strings ("STRINGPREP")", RFC 3454,
December 2002.
[TERMS] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[URL-GUIDE]
Masinter, L., Alvestrand, H., Zigmond, D. and R. Petke,
"Guidelines for new URL Schemes", RFC 2718, November 1999.
[XMPP-CORE]
Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", draft-ietf-xmpp-core-22 (work in
progress), January 2004.
[XMPP-IM] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Instant Messaging and Presence",
draft-ietf-xmpp-im-21 (work in progress), January 2004.
Informative References
[CPIM] Peterson, J., "Common Profile for Instant Messaging
(CPIM)", draft-ietf-impp-im-04 (work in progress), August
2003.
[CPP] Peterson, J., "Common Profile for Presence (CPP)",
draft-ietf-impp-pres-04 (work in progress), August 2003.
[DRAFT-UMPP]
Mahy, R., "A Unified Proposal for Server-to-Server
Presence and Instant Messaging",
draft-mahy-impp-unified-proposal-00 (work in progress),
February 2004.
[IDNA] Faltstrom, P., Hoffman, P. and A. Costello,
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Internet-Draft XMPP SIMPLE Interop February 2004
"Internationalizing Domain Names in Applications (IDNA)",
RFC 3490, March 2003.
[IMP-MODEL]
Day, M., Rosenberg, J. and H. Sugano, "A Model for
Presence and Instant Messaging", RFC 2778, February 2000.
[IMP-REQS]
Day, M., Aggarwal, S. and J. Vincent, "Instant Messaging /
Presence Protocol Requirements", RFC 2779, February 2000.
[IRC] Oikarinen, J. and D. Reed, "Internet Relay Chat Protocol",
RFC 1459, May 1993.
[MSGFMT] Atkins, D. and G. Klyne, "Common Presence and Instant
Messaging: Message Format", draft-ietf-impp-cpim-msgfmt-08
(work in progress), January 2003.
[SIMPLE-CPIM]
Rosenberg, J. and B. Campbell, "CPIM Mapping of SIMPLE
Presence and Instant Messaging",
draft-ietf-simple-cpim-mapping-01 (work in progress), June
2002.
[SIMPLE-MSRP]
Campbell, B., Rosenberg, J., Sparks, R. and P. Kyzivat,
"The Message Session Relay Protocol",
draft-ietf-simple-message-sessions-03 (work in progress),
January 2004.
[XMPP-CPIM]
Saint-Andre, P., "XMPP CPIM Mapping",
draft-ietf-xmpp-cpim-03 (work in progress), November 2003.
Authors' Addresses
Peter Saint-Andre
Jabber Software Foundation
Avshalom Houri
IBM
Joe Hildebrand
Jabber, Inc.
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