Extensible Markup Language (XML) Format Extension for Representing Copy Control Attributes in Resource Lists
RFC 5364
Network Working Group M. Garcia-Martin
Request for Comments: 5364 G. Camarillo
Category: Standards Track Ericsson
October 2008
Extensible Markup Language (XML) Format Extension for Representing
Copy Control Attributes in Resource Lists
Status of This Memo
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.
Abstract
In certain types of multimedia communications, a Session Initiation
Protocol (SIP) request is distributed to a group of SIP User Agents
(UAs). The sender sends a single SIP request to a server which
further distributes the request to the group. This SIP request
contains a list of Uniform Resource Identifiers (URIs), which
identify the recipients of the SIP request. This URI list is
expressed as a resource list XML document. This specification
defines an XML extension to the XML resource list format that allows
the sender of the request to qualify a recipient with a copy control
level similar to the copy control level of existing email systems.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overview of Operation . . . . . . . . . . . . . . . . . . . . 3
4. Extension to the Resource List Data Format . . . . . . . . . . 6
5. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Carrying URI Lists in SIP . . . . . . . . . . . . . . . . . . 10
8. Security Considerations . . . . . . . . . . . . . . . . . . . 11
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
9.1. Disposition Type Registration . . . . . . . . . . . . . . 13
9.2. XML Namespace Registration . . . . . . . . . . . . . . . . 13
9.3. XML Schema Registration . . . . . . . . . . . . . . . . . 14
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . . 15
Garcia-Martin & Camarillo Standards Track [Page 1]
RFC 5364 Copy Control Attribute in Resource Lists October 2008
1. Introduction
RFC 5363 [RFC5363] describes a generic framework for carrying Uniform
Resource Identifier (URI) lists in SIP [RFC3261] messages.
Specifically, the document provides a common framework for specific
implementations of URI-list services, such as conferences initiated
with INVITE requests [RFC5366] or Multiple-recipient MESSAGE requests
[RFC5365].
Common to all URI-list services is the presence of a SIP request that
contains a collection of resources, typically expressed as an XML
resource list [RFC4826]. SIP requests carrying resource lists can
appear either in requests received by the URI-list server, indicating
the list of intended recipients, or in each of the requests that the
URI-list server sends to recipients, indicating the list of
recipients of the same SIP request.
Although the XML resource list [RFC4826] provides a powerful
mechanism for describing a list of resources, there is a need for a
copy control attribute to determine whether a resource is receiving a
SIP request as a primary recipient, a carbon copy, or a blind carbon
copy. This is similar to common email systems, where the sender can
categorize each recipient as a "to", "cc", or "bcc" recipient.
This document addresses this problem by providing an extension to the
XML resource list [RFC4826] that enables the sender to supply a copy
control attribute that labels each recipient as a "to", "cc", or
"bcc" recipient. This attribute indicates whether the recipient is
receiving a primary copy of the SIP request, a carbon copy, or a
blind carbon copy. Additionally, we provide the sender with the
capability of indicating in the URI list that one or more resources
should be anonymized, so that some recipients' URIs are not disclosed
to the other recipients. Instead, these URIs are replaced with
anonymous URIs.
The remainder of this document is organized as follows: Section 2
introduces the terminology used throughout this specification.
Section 3 gives an overview of operation. Section 4 formally defines
an extension to URI lists. The XML schema definition is provided in
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