draft-ietf-sipping-multiple-refer-05.txt   draft-ietf-sipping-multiple-refer-06.txt 
SIPPING Working Group G. Camarillo SIPPING Working Group G. Camarillo
Internet-Draft Ericsson Internet-Draft Ericsson
Expires: November 12, 2006 A. Niemi Intended status: Standards Track A. Niemi
M. Isomaki Expires: December 24, 2006 M. Isomaki
M. Garcia-Martin M. Garcia-Martin
Nokia Nokia
H. Khartabil H. Khartabil
Telio Telio
May 11, 2006 June 22, 2006
Refering to Multiple Resources in the Session Initiation Protocol (SIP) Refering to Multiple Resources in the Session Initiation Protocol (SIP)
draft-ietf-sipping-multiple-refer-05.txt draft-ietf-sipping-multiple-refer-06.txt
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The Internet Society (2006).
Abstract Abstract
This document defines extensions to the SIP REFER method so that this This document defines extensions to the SIP REFER method so that this
method can be used to refer servers to multiple resources. These method can be used to refer servers to multiple resources. These
extensions include the use of pointers to Uniform Resource Identifier extensions include the use of pointers to Uniform Resource Identifier
(URI)-lists in the Refer-To header field and the "multiple-refer" SIP (URI)-lists in the Refer-To header field and the "multiple-refer" SIP
option-tag. option-tag.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overview of operation . . . . . . . . . . . . . . . . . . . . 3 3. Overview of operation . . . . . . . . . . . . . . . . . . . . 3
4. The multiple-refer SIP Option-Tag . . . . . . . . . . . . . . 4 4. The multiple-refer SIP Option-Tag . . . . . . . . . . . . . . 4
5. Suppressing REFER's Implicit Subscription . . . . . . . . . . 4 5. Suppressing REFER's Implicit Subscription . . . . . . . . . . 4
6. Behavior of SIP REFER-Issuers . . . . . . . . . . . . . . . . 5 6. URI-List Format . . . . . . . . . . . . . . . . . . . . . . . 5
7. Behavior of REFER-Recipients . . . . . . . . . . . . . . . . . 5 7. Behavior of SIP REFER-Issuers . . . . . . . . . . . . . . . . 7
8. Default URI-List Format . . . . . . . . . . . . . . . . . . . 5 8. Behavior of REFER-Recipients . . . . . . . . . . . . . . . . . 7
9. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 9. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
10. Security Considerations . . . . . . . . . . . . . . . . . . . 9 10. Security Considerations . . . . . . . . . . . . . . . . . . . 10
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
12.1. Normative References . . . . . . . . . . . . . . . . . . 9 12.1. Normative References . . . . . . . . . . . . . . . . . . 10
12.2. Informational References . . . . . . . . . . . . . . . . 10 12.2. Informational References . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . . . 14
1. Introduction 1. Introduction
The SIP [3] REFER method [5] allows a user agent to request a server The SIP [5] REFER method [7] allows a user agent to request a server
to send a request to a third party. Still, a number of applications to send a request to a third party. Still, a number of applications
need to request a server to initiate transactions towards a set of need to request a server to initiate transactions towards a set of
destinations. In one example, the moderator of a conference may want destinations. In one example, the moderator of a conference may want
the conference server to send BYE requests to a group of the conference server to send BYE requests to a group of
participants. In another example, the same moderator may want the participants. In another example, the same moderator may want the
conference server to INVITE a set of new participants. conference server to INVITE a set of new participants.
We define an extension to REFER so that REFER can be used to refer We define an extension to REFER so that REFER can be used to refer
servers to multiple destinations. In addition, we use the REFER servers to multiple destinations. In addition, this mechanism uses
extension defined in [7] which suppresses REFER's implicit the suppression of the REFER method implicit subscription specified
subscription. in RFC 4488 [8] to suppress REFER's implicit subscription.
2. Terminology 2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED", In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, RFC 2119 [1] and indicate requirement levels for described in BCP 14, RFC 2119 [1] and indicate requirement levels for
compliant implementations. compliant implementations.
We define the following three new terms: We define the following three new terms:
REFER-Issuer: the user agent issuing the REFER request. REFER-Issuer: the user agent issuing the REFER request.
REFER-Recipient: the user agent receiving the REFER request. REFER-Recipient: the user agent receiving the REFER request.
REFER-Target: the intended final recipient of the request to be REFER-Target: the intended final recipient of the request to be
generated by the REFER-Recipient. generated by the REFER-Recipient.
3. Overview of operation 3. Overview of operation
This document defines an extension to the SIP REFER method [5] that This document defines an extension to the SIP REFER method [7] that
allows a SIP User Agent Client (UAC) to include a list of REFER- allows a SIP User Agent Client (UAC) to include a URI-list [9] of
Targets in a REFER request and send it to a server. The server will REFER-Targets in a REFER request and send it to a server. The server
create a new request for each entry in the list of REFER-Target URIs. will create a new request for each entry in the list of REFER-Target
URIs.
We represent the multiple REFER-Targets of a REFER using a URI-list. The URI-list of REFER-Targets is used in conjunction with the
A UAC (User Agent Client) that wants to refer a server to a set of capacity attribute extension [11] to allow the sender indicate the
destinations creates a SIP REFER request. The Refer-To header capacity (e.g., 'to', 'cc', or anonymous) in which the REFER-Target
is involved in the signalling.
We represent the multiple REFER-Targets of a REFER using a URI-list
[9]. A UAC (User Agent Client) that wants to refer a server to a set
of destinations creates a SIP REFER request. The Refer-To header
contains a pointer to a URI-list, which is included in a body part, contains a pointer to a URI-list, which is included in a body part,
and an option-tag in the Required header field: "multiple-refer". and an option-tag in the Required header field: "multiple-refer".
This option-tag indicates the requirement to support the This option-tag indicates the requirement to support the
functionality described in this specification. functionality described in this specification.
When the server receives such request it creates a new request per When the server receives such request it creates a new request per
destination and sends them. destination and sends them.
This document does not provide any mechanism for UACs to find out This document does not provide any mechanism for UACs to find out
about the results of a REFER with multiple REFER-Targets. about the results of a REFER with multiple REFER-Targets.
Furthermore, it does not provide support for the implicit Furthermore, it does not provide support for the implicit
subscription mechanism that is part of the SIP REFER method. The way subscription mechanism that is part of the SIP REFER method. The way
UACs are kept informed about the results of a REFER is service UACs are kept informed about the results of a REFER is service
specific. For example, a UAC sending a REFER to INVITE a set of specific. For example, a UAC sending a REFER to INVITE a set of
participants to a conference may discover which participants were participants to a conference may discover which participants were
successfully brought into the conference by subscribing to the successfully brought into the conference by subscribing to the
conference state event [9]. conference state event [13].
4. The multiple-refer SIP Option-Tag 4. The multiple-refer SIP Option-Tag
We define a new SIP option-tag for the Require and Supported header We define a new SIP option-tag for the Require and Supported header
fields: "multiple-refer". fields: "multiple-refer".
A user agent including the "multiple-refer" option-tag in a Supported A user agent including the "multiple-refer" option-tag in a Supported
header indicates compliance with this specification. header field indicates compliance with this specification.
A user agent generating a REFER with a pointer to a URI-list in its A user agent generating a REFER with a pointer to a URI-list in its
Refer-To header field MUST include the "multiple-refer" option-tag in Refer-To header field MUST include the "multiple-refer" option-tag in
the Require header field of the REFER. the Require header field of the REFER.
5. Suppressing REFER's Implicit Subscription 5. Suppressing REFER's Implicit Subscription
REFER requests with a single REFER-Target establish implicitly a REFER requests with a single REFER-Target establish implicitly a
subscription to the refer event. The REFER-Issuer is informed about subscription to the refer event. The REFER-Issuer is informed about
the result of the transaction towards the REFER-Target through this the result of the transaction towards the REFER-Target through this
implicit subscription. As described in RFC 3515 [5], NOTIFY requests implicit subscription. As described in RFC 3515 [7], NOTIFY requests
sent as a result of an implicit subscription created by a REFER sent as a result of an implicit subscription created by a REFER
request contain a body of type "message/sipfrag" [4] that describes request contain a body of type "message/sipfrag" [6] that describes
the status of the transaction initiated by the REFER-Recipient. the status of the transaction initiated by the REFER-Recipient.
In the case of a REFER-Issuer that generates a REFER with multiple In the case of a REFER-Issuer that generates a REFER with multiple
REFER-targets, the REFER-Issuer is typically already subscribed to REFER-targets, the REFER-Issuer is typically already subscribed to
other event package that can provide the information about the result other event package that can provide the information about the result
of the transactions towards the REFER-Targets. For example, a of the transactions towards the REFER-Targets. For example, a
moderator instructing a conference server to send a BYE request to a moderator instructing a conference server to send a BYE request to a
set of participants is usually subscribed to the conference state set of participants is usually subscribed to the conference state
event package for the conference. Notifications to this event event package for the conference. Notifications to this event
package will keep the moderator and the rest of the subscribers package will keep the moderator and the rest of the subscribers
informed of the current list of conference participants. informed of the current list of conference participants.
Most of the applications using multiple REFER do not need its Most of the applications using multiple REFER do not need its
implicit subscription. Consequently, a SIP REFER-Issuer generating a implicit subscription. Consequently, a SIP REFER-Issuer generating a
REFER request with multiple REFER-Targets SHOULD include the REFER request with multiple REFER-Targets SHOULD include the
"norefersub" option-tag in a Require header field to indicate that no "norefersub" option-tag in a Require header field and SHOULD include
a Refer-Sub header field set to "false" to indicate that no
notifications about the requests should be sent to the REFER-Issuer. notifications about the requests should be sent to the REFER-Issuer.
The "norefersub" SIP option-tag is defined in [7] and suppresses the The REFER-Recipient SHOULD honor the suggestion and also include a
REFER's implicit subscription. Refer-Sub header field set to "false" in the 200 OK response. The
"norefersub" SIP option-tag and the Refer-Sub header field are
specified in RFC 4488 [8].
RFC 4488 [8] indicates that a condition for the REFER-Issuer to
include a Refer-Sub header is that the REFER-Issue is sure that
the REFER request will not fork.
At the time of writing, there is no extension that allows to report At the time of writing, there is no extension that allows to report
the status of several transactions over a REFER's implicit the status of several transactions over a REFER's implicit
subscription. That is the motivation for this document to recommend subscription. That is the motivation for this document to recommend
the usage of the "norefersub" option-tag. If in the future such an the usage of the "norefersub" option-tag. If in the future such an
extension is defined, REFER-Issuers using it could refrain from using extension is defined, REFER-Issuers using it could refrain from using
the "norefersub" option-tag and use the new extension instead. the "norefersub" option-tag and use the new extension instead.
6. Behavior of SIP REFER-Issuers 6. URI-List Format
As indicated in Section 4 and Section 5 a SIP REFER-Issuer that
creates a REFER request with multiple REFER-Targets includes a
"multiple-refer" and a "norefersub" option-tags in the Require header
field.
The Refer-To header field of a REFER request with multiple REFER-
Targets MUST contain a pointer (i.e., a Content-ID Uniform Resource
Locator (URL) [2]) that points to the body part that carries the URI-
list. The REFER-Issuer SHOULD NOT include any particular URI more
than once in the URI-list.
7. Behavior of REFER-Recipients
The REFER-Recipient follows the rules in Section 2.4.2 of RFC 3515 As described in the Framework and Security Considerations for SIP
[5] to determine the status code of the response to the REFER. URI-List Services [10], specifications of individual URI-list
services, need to specify a default format for 'recipient-list'
bodies used within the particular service.
If the URI-list contains a URI more than once, the REFER-Recipient The default format for 'recipient-list' bodies for conferencing UAs
MUST behave as if that URI appeared in the URI-list only once. The (User Agents) and servers is the XML resource list format [9]
REFER-Recipient uses the comparison rules specific to the URI scheme extended with the XML Format Extension for Representing Capacity
of each of the URIs in the URI-list to determine if there is any URI Attributes in Resource Lists [11]. UAs handling 'recipient-list'
which appears more than once. bodies MUST support both of these formats and MAY support other
formats.
The REFER-Recipient follows the rules in RFC 3515 [5] to generate the As described in the XML Format Extension for Representing Capacity
necessary requests towards the REFER-Targets, acting as if it had Attributes in Resource Lists [11], each URI can be tagged with a
received a regular (no URI-list) REFER per each URI in the URI-list. 'capacity' attribute set to either "to", "cc", or "bcc", indicating
the capacity or role in which the recipient will get the referred SIP
request. However, it must be noted that, depending on the target SIP
method, a 'capacity' attribute may not have sense. For example,
while a 'capacity' attribute can be applied to INVITE requests, it
may not make sense with mid-dialog requests such as BYE requests.
8. Default URI-List Format In addition to the 'capacity' attribute, URIs can be tagged with the
'anonymize' attribute, also specified in the XML Format Extension for
Representing Capacity Attributes in Resource Lists [11] to prevent
that the server discloses the target URI in a URI-list.
The default format for URI-list bodies used in a multiple REFER Additionally, the XML Format Extension for Representing Capacity
request is the resource list document specified in [6]. User agents Attributes in Resource Lists [11] defines a 'recipient-list-history'
able to generate or receive REFERs with multiple REFER-Targets MUST body that contains the list of recipients. The default format for
support this format as specified in [6] and MAY support other 'recipient-list-history' bodies for conference services is also the
formats. XML resource list document format [7] extended with the XML Format
Extension for Representing Capacity Attributes in Resource Lists [8].
Conferencing servers MUST support both of these formats; UASes MAY
support these formats. Both conferencing servers and UASes MAY
support other formats.
Nevertheless, the Extensible Markup Language (XML) Configuration Nevertheless, the XML resource list document [9] provides features,
Access Protocol (XCAP) resource list document provides features, such such as hierarchical lists and the ability to include entries by
as hierarchical lists and the ability to include entries by reference reference relative to the XCAP root URI, that are not needed by the
relative to the XCAP root URI, that are not needed by the multiplet multiplet REFER service defined in this document. Therefore, when
REFER service defined in this document. Therefore, when using the using the default resource list document, SIP REFER-Issuers
default resource list document, SIP REFER-Issuers generating REFERs generating REFERs with multiple REFER-Targets SHOULD use flat lists
with multiple REFER-Targets SHOULD use flat lists (i.e., no (i.e., no hierarchical lists) and SHOULD NOT use %lt;entry-ref>
hierarchical lists) and SHOULD NOT use <entry-ref> elements. elements.
A REFER-Recipient receiving a URI-list with more information than A REFER-Recipient receiving a URI-list with more information than
what has just been described MAY discard all the extra information. what has just been described MAY discard all the extra information.
Figure 1 shows an example of a flat list that follows the resource Figure 1 shows an example of a flat list that follows the resource
list document. list document.
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<resource-lists xmlns="urn:ietf:params:xml:ns:resource-lists" <resource-lists xmlns="urn:ietf:params:xml:ns:resource-lists"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> xmlns:cp="urn:ietf:params:xml:ns:capacity">
<list> <list>
<entry uri="sip:bill@example.com" /> <entry uri="sip:bill@example.com" cp:capacity="to" />
<entry uri="sip:joe@example.org" /> <entry uri="sip:joe@example.org" cp:capacity="cc" />
<entry uri="sip:ted@example.net" /> <entry uri="sip:ted@example.net" cp:capacity="bcc" />
</list> </list>
</resource-lists> </resource-lists>
Figure 1: URI List Figure 1: URI List
7. Behavior of SIP REFER-Issuers
As indicated in Section 4 and Section 5 a SIP REFER-Issuer that
creates a REFER request with multiple REFER-Targets includes a
"multiple-refer" and "norefersub" option-tags in the Require header
field and, if appropriate, a Refer-Sub header field set to "false".
The REFER-Issuer includes the set of REFER-Targets in body whose
disposition type is 'recipient-list', as defined in the Framework and
Security Considerations for SIP URI-List Services [10]. The URI-list
body is further described in Section 6.
The Refer-To header field of a REFER request with multiple REFER-
Targets MUST contain a pointer (i.e., a Content-ID Uniform Resource
Locator (URL) [3] ) that points to the body part that carries the
URI-list. The REFER-Issuer SHOULD NOT include any particular URI
more than once in the URI-list.
8. Behavior of REFER-Recipients
The REFER-Recipient follows the rules in Section 2.4.2 of RFC 3515
[7] to determine the status code of the response to the REFER.
The REFER-Recipient SHOULD not create an implicit subscription, and
SHOULD add a Refer-Sub header field set to "false" in the 200 OK
response.
If the URI-list of the REFER request contains a repeated URI, the
REFER-Recipient MUST behave as if that URI appeared in the URI-list
only once. The REFER-Recipient uses the comparison rules specific to
the URI scheme of each of the URIs in the URI-list to determine if
there is any URI which appears more than once.
The incoming REFER request typically contains a URI-list document or
reference with the actual list of recipients. If this URI-list
includes resources tagged with the 'capacity' attribute set to a
value of "to" or "cc", and if appropriate for the service, e.g., if
it is non-mid dialog request, the URI-list server SHOULD include a
URI-list in each of the outgoing requests. This list SHOULD be
formatted according to the XML format for representing resource lists
[9] and the capacity extension [11]. The URI-list server MUST follow
the procedures specified in XML format for representing resource
lists [9] with respect handling of the 'anonymize', 'count' and
'capacity' attributes.
If the server includes a URI-list in an outgoing request, it MUST
include a Content-Disposition header field [2] with the value set to
'recipient-list-history' and a 'handling' parameter [4] set to
"optional".
The REFER-Recipient follows the rules in RFC 3515 [7] to generate the
necessary requests towards the REFER-Targets, acting as if it had
received a regular (no URI-list) REFER per each URI in the URI-list.
9. Example 9. Example
Figure 2 shows an example flow where a REFER-Issuer sends a multiple- Figure 2 shows an example flow where a REFER-Issuer sends a multiple-
REFER request to the focus of a conference, which acts as the REFER- REFER request to the focus of a conference, which acts as the REFER-
Recipient. The REFER-Recipient generates a BYE request per REFER- Recipient. The REFER-Recipient generates a BYE request per REFER-
Target. (How to use REFER to remove participants from a conference Target. (How to use REFER to remove participants from a conference
is specified in [10].) is specified in [14].)
+--------+ +---------+ +--------+ +--------+ +--------+ +--------+ +---------+ +--------+ +--------+ +--------+
| REFER | | REFER | | REFER | | REFER | | REFER | | REFER | | REFER | | REFER | | REFER | | REFER |
| issuer | |recipient| |target 1| |target 2| |target 3| | issuer | |recipient| |target 1| |target 2| |target 3|
+--------+ +---------+ +--------+ +--------+ +--------+ +--------+ +---------+ +--------+ +--------+ +--------+
| 1. REFER | | | | | 1. REFER | | | |
| ---------------->| | | | | ---------------->| | | |
| 2. 202 Accepted | | | | | 2. 202 Accepted | | | |
|<---------------- | 3. BYE | | | |<---------------- | 3. BYE | | |
| | ----------->| | | | | ----------->| | |
| | 4. BYE | | | | | 4. BYE | | |
skipping to change at page 7, line 32 skipping to change at page 8, line 46
| |<----------------------------------- | | |<----------------------------------- |
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |
Figure 2: Example flow or a REFER request containin multiple REFER- Figure 2: Example flow or a REFER request containin multiple REFER-
Targets Targets
The REFER request (1) contains a Refer-To header field that includes The REFER request (1) contains a Refer-To header field that includes
a pointer to the message body, which carries a list with the URIs of a pointer to the message body, which carries a list with the URIs of
the REFER-Targets. The REFER's Require header field carries both the the REFER-Targets. In this example, the URI-list does not contain
"multiple-refer" and the "norefersub" option-tags. Figure 3 shows an the capacity attribute extension. The REFER's Require header field
example of this REFER request. The resource list document contains carries the "multiple-refer" and "norefersub" option-tags. The
the list of REFER-Target URIs along with the method of the SIP Request-URI is set to a Globally Routable User Agent URIs (GRUU) [12]
request that the REFER-Recipient generates. (as a guarantee that the REFER request will not fork). The Refer-Sub
header field is set to "false" to request the suppression of the
implicit subscription. Figure 3 shows an example of this REFER
request. The resource list document contains the list of REFER-
Target URIs along with the method of the SIP request that the REFER-
Recipient generates.
REFER sip:conf-123@example.com SIP/2.0 REFER sip:conf-123@example.com;gruu;opaque=hha9s8d-999a SIP/2.0
Via: SIP/2.0/TCP client.chicago.example.com Via: SIP/2.0/TCP client.chicago.example.com
;branch=z9hG4bKhjhs8ass83 ;branch=z9hG4bKhjhs8ass83
Max-Forwards: 70 Max-Forwards: 70
To: "Conference 123" <sip:conf-123@example.com> To: "Conference 123" <sip:conf-123@example.com>
From: Carol <sip:carol@chicago.example.com>;tag=32331 From: Carol <sip:carol@chicago.example.com>;tag=32331
Call-ID: d432fa84b4c76e66710 Call-ID: d432fa84b4c76e66710
CSeq: 2 REFER CSeq: 2 REFER
Contact: <sip:carol@client.chicago.example.com> Contact: <sip:carol@client.chicago.example.com>
Refer-To: <cid:cn35t8jf02@example.com> Refer-To: <cid:cn35t8jf02@example.com>
Refer-Sub: false
Require: multiple-refer, norefersub Require: multiple-refer, norefersub
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Allow-Events: dialog Allow-Events: dialog
Accept: application/sdp, message/sipfrag Accept: application/sdp, message/sipfrag
Content-Type: application/resource-lists+xml Content-Type: application/resource-lists+xml
Content-Disposition: uri-list Content-Disposition: recipient-list
Content-Length: 307 Content-Length: 362
Content-ID: <cn35t8jf02@example.com> Content-ID: <cn35t8jf02@example.com>
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<resource-lists xmlns="urn:ietf:params:xml:ns:resource-lists" <resource-lists xmlns="urn:ietf:params:xml:ns:resource-lists"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<list> <list>
<entry uri="sip:bill@example.com?method=BYE" /> <entry uri="sip:bill@example.com?method=BYE" />
<entry uri="sip:joe@example.org?method=BYE" /> <entry uri="sip:joe@example.org?method=BYE" />
<entry uri="sip:ted@example.net?method=BYE" /> <entry uri="sip:ted@example.net?method=BYE" />
</list> </list>
skipping to change at page 9, line 8 skipping to change at page 10, line 20
To: <sip:bill@example.com>;tag=29872 To: <sip:bill@example.com>;tag=29872
Call-ID: d432fa84b4c34098s812 Call-ID: d432fa84b4c34098s812
CSeq: 34 BYE CSeq: 34 BYE
Content-Length: 0 Content-Length: 0
Figure 4: BYE request Figure 4: BYE request
10. Security Considerations 10. Security Considerations
The Framework and Security Considerations for SIP URI-List Services The Framework and Security Considerations for SIP URI-List Services
[8] discusses issues related to SIP URI-list services. Given that a [10] discusses issues related to SIP URI-list services. Given that a
server accepting REFERs with multiple REFER-targets acts as an URI- server accepting REFERs with multiple REFER-targets acts as an URI-
list service, implementations of this type of server MUST follow the list service, implementations of this type of server MUST follow the
security-related rules in [8]. These rules include mandatory security-related rules in [10]. These rules include mandatory
authentication and authorization of clients, and opt-in lists. authentication and authorization of clients, and opt-in lists.
Additionally, servers SHOULD only accept REFER requests within the Additionally, servers SHOULD only accept REFER requests within the
context of an application the server understands (e.g., a context of an application the server understands (e.g., a
conferencing application). This implies that servers MUST NOT accept conferencing application). This implies that servers MUST NOT accept
REFERs for methods they do not understand. The idea behind these two REFERs for methods they do not understand. The idea behind these two
rules is that servers are not used as dumb servers whose only rules is that servers are not used as dumb servers whose only
function is to fan-out random messages they do not understand. function is to fan-out random messages they do not understand.
11. IANA Considerations 11. IANA Considerations
skipping to change at page 9, line 37 skipping to change at page 10, line 49
Supported header field understand REFER requests that contain Supported header field understand REFER requests that contain
resource list document describing multiple REFER-Targets. resource list document describing multiple REFER-Targets.
12. References 12. References
12.1. Normative References 12.1. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[2] Levinson, E., "Content-ID and Message-ID Uniform Resource [2] Troost, R., Dorner, S., and K. Moore, "Communicating
Presentation Information in Internet Messages: The Content-
Disposition Header Field", RFC 2183, August 1997.
[3] Levinson, E., "Content-ID and Message-ID Uniform Resource
Locators", RFC 2392, August 1998. Locators", RFC 2392, August 1998.
[3] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., [4] Zimmerer, E., Peterson, J., Vemuri, A., Ong, L., Audet, F.,
Watson, M., and M. Zonoun, "MIME media types for ISUP and QSIG
Objects", RFC 3204, December 2001.
[5] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A.,
Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP:
Session Initiation Protocol", RFC 3261, June 2002. Session Initiation Protocol", RFC 3261, June 2002.
[4] Sparks, R., "Internet Media Type message/sipfrag", RFC 3420, [6] Sparks, R., "Internet Media Type message/sipfrag", RFC 3420,
November 2002. November 2002.
[5] Sparks, R., "The Session Initiation Protocol (SIP) Refer [7] Sparks, R., "The Session Initiation Protocol (SIP) Refer
Method", RFC 3515, April 2003. Method", RFC 3515, April 2003.
[6] Rosenberg, J., "Extensible Markup Language (XML) Formats for [8] Levin, O., "Suppression of Session Initiation Protocol (SIP)
REFER Method Implicit Subscription", RFC 4488, May 2006.
[9] Rosenberg, J., "Extensible Markup Language (XML) Formats for
Representing Resource Lists", Representing Resource Lists",
draft-ietf-simple-xcap-list-usage-05 (work in progress), draft-ietf-simple-xcap-list-usage-05 (work in progress),
February 2005. February 2005.
[7] Levin, O., "Suppression of Session Initiation Protocol REFER [10] Camarillo, G. and A. Roach, "Framework and Security
Method Implicit Subscription",
draft-ietf-sip-refer-with-norefersub-04 (work in progress),
January 2006.
[8] Camarillo, G. and A. Roach, "Framework and Security
Considerations for Session Initiation Protocol (SIP) Uniform Considerations for Session Initiation Protocol (SIP) Uniform
Resource Identifier (URI)-List Services", Resource Identifier (URI)-List Services",
draft-ietf-sipping-uri-services-05 (work in progress), draft-ietf-sipping-uri-services-05 (work in progress),
January 2006. January 2006.
[11] Garcia-Martin, M. and G. Camarillo, "Extensible Markup Language
(XML) Format Extension for Representing Capacity Attributes in
Resource Lists", draft-ietf-sipping-capacity-attribute-00 (work
in progress), February 2006.
[12] Rosenberg, J., "Obtaining and Using Globally Routable User
Agent (UA) URIs (GRUU) in the Session Initiation Protocol
(SIP)", draft-ietf-sip-gruu-07 (work in progress), May 2006.
12.2. Informational References 12.2. Informational References
[9] Rosenberg, J., "A Session Initiation Protocol (SIP) Event [13] Rosenberg, J., "A Session Initiation Protocol (SIP) Event
Package for Conference State", Package for Conference State",
draft-ietf-sipping-conference-package-12 (work in progress), draft-ietf-sipping-conference-package-12 (work in progress),
July 2005. July 2005.
[10] Levin, O., "Session Initiation Protocol Call Control - [14] Levin, O., "Session Initiation Protocol Call Control -
Conferencing for User Agents", Conferencing for User Agents",
draft-ietf-sipping-cc-conferencing-07 (work in progress), draft-ietf-sipping-cc-conferencing-07 (work in progress),
June 2005. June 2005.
Authors' Addresses Authors' Addresses
Gonzalo Camarillo Gonzalo Camarillo
Ericsson Ericsson
Hirsalantie 11 Hirsalantie 11
Jorvas 02420 Jorvas 02420
skipping to change at page 11, line 38 skipping to change at page 13, line 4
Email: Markus.Isomaki@nokia.com Email: Markus.Isomaki@nokia.com
Miguel A. Garcia-Martin Miguel A. Garcia-Martin
Nokia Nokia
P.O.Box 407 P.O.Box 407
NOKIA GROUP, FIN 00045 NOKIA GROUP, FIN 00045
Finland Finland
Email: miguel.an.garcia@nokia.com Email: miguel.an.garcia@nokia.com
Hisham Khartabil Hisham Khartabil
Telio Telio
P.O. Box 1203 P.O. Box 1203
Oslo 0110 Oslo 0110
Norway Norway
Email: Hisham.Khartabil@telio.no Email: Hisham.Khartabil@telio.no
Intellectual Property Statement Full Copyright Statement
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This document is subject to the rights, licenses and restrictions
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This document and the information contained herein are provided on an
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OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
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The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
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skipping to change at page 12, line 29 skipping to change at page 14, line 45
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OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY 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.
Copyright Statement
Copyright (C) The Internet Society (2006). 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.
Acknowledgment Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is provided by the IETF
Internet Society. Administrative Support Activity (IASA).
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