SIPPING                                                        D. Petrie
   Internet Draft
Internet-Draft                                             Pingtel Corp.
   draft-ietf-sipping-config-framework-00.txt
Expires: Aug 2003                                   Feb April 21, 2004                                 October 22, 2003

            A Framework for SIP User Agent Configuration Profile Delivery
               draft-ietf-sipping-config-framework-01.txt

Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026.

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   This Internet-Draft will expire on April 21, 2004.

Copyright Notice

   Copyright (C) The Internet Society (2003). All Rights Reserved.

Abstract

   This document defines the application of a set of protocols for
   configuring a SIP user agent.  The
   providing profile data to SIP user agent must discover how
   and from where to retrieve its initial configuration and be notified
   of changes and updates which impact its configuration. agents.  The objective is to
   define a means for automatically configuring providing profile data a user agent such that it can
   needs to be functional without user or administrative intervention.
   The framework for discovery, delivery, notification and updates of
   user agent configuration profile data is defined here.  As part of this framework a
   new SIP event package is defined here for the notification of profile
   changes.  This framework is also intended to ease ongoing administration,
   configuration
   administration and upgrading of large scale deployments of SIP user
   agents.  The contents and format of the configuration profile data to be defined is
   outside the scope of this document.

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                       User Agent Configuration

Table of Contents

   Status of this Memo................................................1
   Abstract...........................................................1
   1  Overview.......................................................3
   2  Conventions used in this document..............................4

   1.   Motivation . . . . . . . . . . . . . . . . . . . . . . . . .   3  Changes from Previous Draft....................................4
   3.1  Changes from draft-petrie-sipping-config-framework-00.txt....4
   3.2  Changes from draft-petrie-sip-config-framework-01.txt........4
   3.3  Changes from draft-petrie-sip-config-framework-00.txt........4
   4  Discovery......................................................5
   4.1  DHCP Option..................................................6
   4.2  DNS..........................................................6
   4.3  Multicast....................................................7
   4.4  Manually Provisioned.........................................7
   5  Enrollment and Change Notification.............................7
   5.1  SUBSCRIBE....................................................8
   5.1.1 Additional User Agent Field Parameters......................9
   5.2  NOTIFY......................................................10
   5.2.1 NOTIFY Body Content Format.................................11
   6  Configuration Retrieval.......................................11
   7  Configuration Upload..........................................11
   8  Examples......................................................12
   8.1  Example Message Flows.......................................12
   8.2  Example Messages............................................14
   9  Security Considerations.......................................17
   10 Open Issues...................................................18
   11 References....................................................19
   12 Author's Address..............................................20

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                         A
   2.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.1  Requirements Terminology . . . . . . . . . . . . . . . . . .   3
   2.2  Profile Delivery Framework for SIP                Feb. 2003
                       User Agent Configuration

1 Terminology . . . . . . . . . . .   4
   2.3  Overview

   Today all SIP UA vendors use proprietary means of delivering
   configuration to the UA.  This configuration framework is intended
   to enable a first phase migration to a standard means of configuring
   SIP user . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.   Profile Change Event Notification Package  . . . . . . . . .   5
   3.1  Event Package Name . . . . . . . . . . . . . . . . . . . . .   6
   3.2  Event Package Parameters . . . . . . . . . . . . . . . . . .   6
   3.3  SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . . .   7
   3.4  Subscription Duration  . . . . . . . . . . . . . . . . . . .   7
   3.5  NOTIFY Bodies  . . . . . . . . . . . . . . . . . . . . . . .   8
   3.6  Notifier processing of SUBSCRIBE requests  . . . . . . . . .   8
   3.7  Notifier generation of NOTIFY requests . . . . . . . . . . .   9
   3.8  Subscriber processing of NOTIFY requests . . . . . . . . . .  10
   3.9  Handling of forked requests  . . . . . . . . . . . . . . . .  10
   3.10 Rate of notifications  . . . . . . . . . . . . . . . . . . .  10
   3.11 State Agents . . . . . . . . . . . . . . . . . . . . . . . .  10
   3.12 Examples . . . . . . . . . . . . . . . . . . . . . . . . . .  10
   3.13 Use of URIs to Retrieve State  . . . . . . . . . . . . . . .  11
   4.   Profile Delivery Framework Details . . . . . . . . . . . . .  12
   4.1  Discovery of Subscription URI  . . . . . . . . . . . . . . .  12
   4.2  Enrollment with Profile Server . . . . . . . . . . . . . . .  13
   4.3  Notification of Profile Changes  . . . . . . . . . . . . . .  13
   4.4  Retrieval of Profile Data  . . . . . . . . . . . . . . . . .  14
   4.5  Upload of Profile Changes  . . . . . . . . . . . . . . . . .  14
   5.   IANA Considerations  . . . . . . . . . . . . . . . . . . . .  14
   6.   Security Considerations  . . . . . . . . . . . . . . . . . .  14
   6.1  Symmetric Encryption of Profile Data . . . . . . . . . . . .  14
   6.2  Client Certificate Authentication with HTTPS . . . . . . . .  15
   6.3  HTTPS Authentication . . . . . . . . . . . . . . . . . . . .  15
   7.   Differences from Simple XCAP Package . . . . . . . . . . . .  15
   8.   Open Issues  . . . . . . . . . . . . . . . . . . . . . . . .  16
   9.   Change History . . . . . . . . . . . . . . . . . . . . . . .  16
   9.1  Changes from draft-ietf-sipping-config-framework-00.txt  . .  16
   9.2  Changes from draft-petrie-sipping-config-framework-00.txt  .  17
   9.3  Changes from draft-petrie-sip-config-framework-01.txt  . . .  17
   9.4  Changes from draft-petrie-sip-config-framework-00.txt  . . .  17
        References . . . . . . . . . . . . . . . . . . . . . . . . .  18
        Author's Address . . . . . . . . . . . . . . . . . . . . . .  20
   A.   Acknowledgments  . . . . . . . . . . . . . . . . . . . . . .  20
        Intellectual Property and Copyright Statements . . . . . . .  21

1. Motivation

   Today all SIP user agent vendors use proprietary means of delivering
   user or device profiles to the user agent.  The profile delivery
   framework defined in this document is intended to enable a first
   phase migration to a standard means of providing profiles to SIP user
   agents.  It is expected that UA vendors should will be able to use this configuration
   framework as a means of delivering their existing proprietary configuration user
   and device data profiles (i.e. using their existing proprietary
   binary or text formats).  This in itself is a tremendous advantage in
   that a SIP environment can use a single
   configuration profile delivery server to deliver configuration for
   profile data to UAs user agents from multiple vendors.  Follow-on
   standardization activities can: 1)
   1.  define a standard profile content format framework (e.g. XML with
       name spaces [??] or name-value pairs [8]) and 2) [RFC0822]).
   2.  specify the content (i.e. name the configuration parameters) profile data parameters, xml
       schema, name spaces) of the
   configuration data profiles.

   This

   One of the objectives of the framework described in this document defines is
   to provide a start up experience similar to that of users of an
   analog telephone.  When you plug in an analog telephone it just works
   (assuming the line is live and the switch has been provisioned).
   There is no end user configuration required to make analog phone work
   (at least in a basic sense).  So the objective here is to be able to
   take a new SIP user agent out of the box, plug it in (or install the
   software) and have it get its profiles without human intervention
   (other than security measures).  This is necessary for cost effective
   deployment of large numbers of user agents.

   Another objective is to provide a scalable means for on going
   administration of profiles.  Administrators and users are likely to
   want to make changes to user and device profiles.

   Additional requirements for the framework which allows defined in this document
   are described in: [I-D.ietf-sipping-ua-prof-framewk-reqs],
   [I-D.sinnreich-sipdev-req]

2. Introduction

2.1 Requirements Terminology

   Keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT" and
   "MAY" that appear in this document are to be interpreted as described
   in RFC 2119[RFC2119].

2.2 Profile Delivery Framework Terminology

   profile - data set specific to a user or device.
   device - SIP user agents (UA) agent, either software or hardware appliance.
   profile content server - The server that provides the content of the
      profiles using the protocol specified by the URL scheme.
   notifier - The SIP user agent server which processes SUBSCRIBE
      requests for events and sends NOTIFY requests with profile URL(s).
   profile delivery server - The logical collection of the SIP  notifier
      and the server which provides the contents of the profile URL(s).

2.3 Overview

   The profile life cycle can be described by five functional steps.
   These steps are not necessarily discrete.  However it is useful to automatically:
   describe these steps as logically distinct.   These steps are named
   as follows:

   Discovery -  discover a configuration profile delivery server (Discovery)
   Enrollment - enroll with the configuration profile delivery server (Enrollment)
   Profile Retrieval - retrieve configuration profile data (Configuration Retrieval)
   Profile Change Notification - receive notification of configuration profile changes (Change
          Notification)
   Profile Change Upload - upload configuration profile data changes back to the server
          (Configuration Upload)

   The content and format of the data is not defined in this document.
   It will be defined in configuration data profile(s) in other
   document(s). The goal of this framework is to satisfy the
   requirements for configuration delivery defined in [10], [11] and
   [16] explicitly excluding the requirements which pertain to
   configuration data
      profile content and format. delivery server

   Discovery is the process by which a UA SHOULD find the address and
   port at which it SHOULD enroll with the configuration profile delivery server.  As
   there is no single discovery mechanism which will work in all network
   environments, a number of discovery mechanisms are defined
   with a prescribed order in which the UA SHOULD try them until one
   succeeds.

   Enrollment is the process by which a UA SHOULD make itself known to
   the configuration server. In enrolling the UA MUST provide identity
   information, name requested configuration data profile and supported
   protocols for configuration retrieval.  It SHOULD also SUBSCRIBE to
   a mechanism for notification of configuration changes.  As a result
   of enrollment, the UA receives a URL for each of the configuration
   data profiles that the configuration server is able to provide.
   Each profile requires a separate enrollment or SUBSCRIBE session.

   Configuration Retrieval is the process of retrieving the content for
   each of the configuration data profiles the UA requested.

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   Change Notification is the process by which the configuration server
   notifies the UA that the content of one or more of the configuration
   data profiles has changed. Subsequently the UA SHOULD retrieve the
   data profile from the specified URL upon receipt of are defined with a
   prescribed order in which the change
   notification.

   Configuration Upload UA SHOULD try them until one succeeds.

   Enrollment is the process by which a UA or other entity
   pushes a change to a configuration data profile back up SHOULD make itself known to
   the
   configuration profile delivery server.

2  Conventions used in this document

   The 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 [1].

   The syntax and semantics used here extend those defined in SIP (RFC
   2543) [6]. SIP is described in an augmented Backus-Naur form (ABNF).
   See [6, section C] for an overview of ABNF.

3  Changes from Previous Draft

3.1 Changes from draft-petrie-sipping-config-framework-00.txt

   Changed name to reflect SIPPING work group item

   Updated with changes to SIP DHCP [3], SIP [6], SIP Events [7] and
   content indirection [15].

   Moved In enrolling the device UA MUST provide
   identity parameters from the From field parameters
   to User-Agent header parameters.

   Many thanks to Rich Schaaf of Pingtel, Cullen Jennings of Cisco information, name requested profile type(s) and
   Adam Roach of Dyamicsoft supported
   protocols for the great comments and input.

3.2 Changes from draft-petrie-sip-config-framework-01.txt

   Changed the name as this belongs in the SIPPING work group.

   Minor edits

3.3 Changes from draft-petrie-sip-config-framework-00.txt

   Many thanks profile retrieval.  It SHOULD also subscribe to those who contributed and commented on the previous
   draft.  Detailed comments were provided by Henning Schulzrinne from
   Columbia U., Cullen Jennings from Cisco, Rohan Mahy from Cisco, Rich
   Schaaf from Pingtel.

   Split a
   mechanism for notification of profile changes.  As a result of
   enrollment, the enrollment into UA receives a single SUBSCRIBE dialog URL for each
   profile.  The 00 draft sent of the profiles that the
   profile delivery server is able to provide.  Each profile type (set)
   requires a single separate enrollment or SUBSCRIBE listing all session.

   Profile Retrieval is the process of retrieving the
   desired.  These have been split so that content for each enrollment can be
   routed differently.  As there is a concept
   of device specific and

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                       User Agent Configuration

   user specific profiles, these may also be managed on separate
   servers.  For instance in a roaming situation the device might get
   itĂs configuration from a local server profiles the UA requested.

   Profile Change Notification is the process by which knows the LAN specific
   configuration.  At profile
   delivery server    notifies the same time UA that the content of one or more of
   the user specific profiles might
   come from has changed. Subsequently the userĂs home environment configuration server.'

   Removed UA SHOULD retrieve the Config-Expires header as it is largely superfluous with
   profile from the SUBSCRIBE Expires header.

   Eliminated some specified URL upon receipt of the complexity in change
   notification.

   Profile Upload is the discovery mechanism.

   Suggest caching information discovered about process by which a UA or other entity (e.g.
   OSS, corporate directory or configuration server
   to avoid an avalanche problem when management server) pushes a whole building full of devices
   powers up.

   Added
   change to the User-Profile From header field parameter so that profile data back up to the
   device can a request profile delivery server.

   This framework defines a user specific new SIP event package [RFC3265] to solve
   enrollment and profile change notification steps.

   The question arises as to why SIP should be used for a user that the profile
   delivery framework.  In this document SIP is
   different from used for only a small
   portion of the deviceĂs default user.

4  Discovery

   The purpose framework.  Other existing protocols are more
   appropriate for transport of discovery is to figure out how to address the
   configuration server so that profile contents (upstream and
   downstream of the device can enroll. user agent) and are suggested in this document.
   The enrollment
   process involves sending discovery step is simply a specified order and application of
   existing protocols.  SIP SUBSCRIBE.  Prior to this is only needed for the
   discovery process must find enrollment and change
   notification functionality of the address profile delivery framework.  In
   many SIP environments (e.g. carrier/subscriber and multi-site
   enterprise) firewall, NAT and IP addressing issues make it difficult
   to use in the URL for get messages between the
   URI profile delivery server and To header field.  The URL SHOULD use the user id:
   sipuaconfig.  From a
   agent requiring the profiles.

   With SIP perspective the configuration server is
   simply a user agent. By using users and devices already are assigned globally routable
   addresses.  In addition the well known firewall and NAT problems are already
   presumably solved in the environments in which SIP user id, this makes it
   easy for proxy servers agents are to
   be provisioned to route the enrollment
   requests from devices to used.  Therefore SIP is the appropriate configuration server best solution for allowing the domain.

   The first time a UA is plugged in it does not know the address or
   port at which user
   agent to enroll with the local configuration server.  It
   must discover this address and port.  A UA SHOULD support all profile delivery server which may require
   traversal of multiple firewalls and NATs.  For the
   listed discovery mechanisms.  It MUST support at least one same reason the
   notification of them.
   Once profile changes is best solved by SIP.

   It is assumed that the UA has discovered content delivery server MUST be either in the address
   public network or accessible through a DMZ.  The user agents
   requiring profiles may be behind firewalls and port NATs and has successfully
   enrolled with the configuration server, the UA SHOULD cache many
   protocols, such as HTTP, may be used for profile content retrieval
   without special consideration in the
   address firewalls and port NATs.

   A conscious separation of user and device profiles is made in this
   document.  This is useful to avoid the need provide features such as hoteling as
   well as securing or restricting user agent functionality.  By
   maintaining this separation, a user may walk up to re-discover someone else's
   user agent and direct that user agent to get their profile data.  In
   doing so the configuration
   server.  However if enrollment, configuration retrieval or
   configuration upload fails at any time, user agent can replace the UA SHOULD apply previous user's profile data
   while still keeping the
   discovery devices profile data that may be necessary
   for core functionality and enrollment process again. communication described in this document.

3. Profile Change Event Notification Package

   This provides section defines a means for
   configuration server fail over and load balancing. new SIP event package [RFC3265].  The UA SHOULD use the following mechanisms purpose
   of this event package is to send to subscribers notification of
   content changes to discover the host
   address profile(s) of interest and port at which it SHOULD enroll with to provide the configuration
   server.  Each mechanism should be tried in
   location of the following order until
   an address and port profile(s) via content indirection
   [I-D.ietf-sip-content-indirect-mech].

3.1 Event Package Name

   The name of this package is provided which results "sip-profile". This value appears in successful
   enrollment (i.e. the server responds with a successful 2xx class
   response):
        - DHCP option
   Event header field present in SUBSCRIBE and NOTIFY requests for SIP [3]
        - DNS A record
        - Multicast
        - Manual provisioning

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                         A Framework this
   package as defined in [RFC3265].

3.2 Event Package Parameters

   This package defines the following new parameters for SIP                Feb. 2003
                       User Agent Configuration the event
   header: profile-type, vendor, model, version, effective-by.  The rationale
   effective-by parameter is for this order follows.  Assuming that most UAs are
   going to use DHCP in NOTIFY requests only.  The
   others are for IP configuration anyway, using a DHCP option
   is use in the least costly SUBSCRIBE request, but may be used in terms of lookup time (i.e. no additional
   messages are required).  Hence DHCP is first.  Multicast
   NOTIFY requests as well.

   The profile-type parameter is used
   last of to indicate the automated discovery mechanisms as it is profile type the most
   restricted in terms
   user agent wishes to obtain URLs for and be notified of network environments that support it.
   Multicast is included, even though change.  This
   parameter allows the applicable environments are
   restricted, URL semantics to be opaque to the subscribing
   user agent as all it needs to know is the only mechanism that can be used without the
   support token value for this
   parameter.  This document defines two type categories of the local network administrator. profiles.
   The phone administrator and contents or format of the network administrator profiles is outside the scope of this
   document.  The two types of profiles define here are often
        different people "user" and perhaps in different departments.

   The UA implementer MAY provide
   "device".  Specifying device type profile(s) indicates the user or administrator with desire for
   the
   means to URL(s) and change the order in which these mechanisms notification of all profiles that are tried.  This
   includes the ability specific
   to manually override the discovery process.
   However by default without device or user agent.  Specifying user interaction type profile(s)
   indicates the UA SHOULD use desire for the
   order listed above.

   Once discovery is successful URL(s) and change notification of all
   profile(s) that are specific to the user.  The user or device SHOULD persistently cache is
   identified in the address to avoid avalanche problems when a whole building full URI of devices powers up at once. the SUBSCRIBE request.  The characteristic Accept header of
   the SUBSCRIBE request MUST include the MIME types for all profile may
   dictate this behavior.  For example
   content types that the subscribing user agent wishes to retrieve
   profiles or receive change notifications.

      The user or device specific token in the profile-type parameter may
      represent a class or set of profiles as opposed to a single
      profile.  As standards are defined for specific profile contents
      related to the user or device, it may
   need be desirable to change when define
      additional tokens for the device profile-type header.  This is moved to allow a different location.
   User
      user agent to subscribe to that specific profiles may be independent of profile as opposed to the LAN, network
      entire class or set of user or device location.

4.1 DHCP Option

It profiles.

   The rational for the separation of user and device type profiles is likely
   provided in section Section 2.3.  It should be noted that most UAs either type
   may indicate that zero or more URLs are provided in an deployment of any significant size
will use DHCP for IP configuration.  DHCP becomes the NOTIFY
   request.  As discussed, a convenient means default user may be assigned to
discover a device.
   In this scenario the configuration profile delivery server address.  In may provide the same DHCP URL(s)
   in the NOTIFY request for basic IP configuration, the UA can add the option for SIP[3] [1] default user when subscribing to the options field.  This indicates
   device profile type.  Effectively the  device profile type becomes a request
   superset of the user profile type subscription.  The user type is
   still useful in this scenario to allow the user agent to obtain
   profile URLs for a user other than the default SIP proxy
server address and port.  For example if user.  This provides
   the DHCP option for SIP
returns an address of sip.acme.com ability to support a hoteling function where a user may "login"
   to any user agent and have it use a port users profile(s).

   The vendor, model and version parameters are tokens specified by the
   vendor of 5080, the following
URL is constructed: sip:sipuaconfig@sip.acme.com:5080.  If user agent.  These parameters are useful to the proxy profile
   delivery server address and port to effect the profiles provided.  In some scenarios
   it is not returned desirable to provide different profiles based upon these
   parameters.  For example feature parameter X in a profile may work
   differently on two versions of user agent.  This gives the DHCP response or the profile
   deliver server does not respond to the enrollment request with a successful 2xx
class response, ability to compensate for or take advantage of the next discovery mechanism is attempted.

4.2 DNS
   differences.

   The UA SHOULD construct a fully qualified host name using
   ˘sipuaconfig÷ as "effective-by" parameter in the Event header of the NOTIFY
   specifies the maximum number of seconds before the host and user agent MUST
   make the local domain if defined.  It
   SHOULD try a DNS new profile effective.  A record lookup on value of 0 (zero) indicates that
   the fully qualified host name.
   If user agent MUST make the name resolves in DNS it should then attempt enrollment.  For
   example profiles effective immediately (despite
   possible service interruptions).  This gives the URL constructed in profile delivery
   server the local domain of acme.com would
   look like: sip:sipuaconfig@sipuaconfig.acme.com.  If power to control when the server does
   not respond profile is effective.  This may
   be important to enrollment with resolve an emergency problem or disable a successful 2xx class response, user agent
   immediately.

   SUBSCRIBE request example:
   Event: sip-profile;profile-type=device;
               vendor=acme;model=Z100;version=1.2.3

   NOTIFY request examples:
   Event:sip-profile;effective-by=0

   Event:sip-profile;effective-by=3600

3.3 SUBSCRIBE Bodies

   This package defines no new use of the
   next discovery mechanism SUBSCRIBE request body.

3.4 Subscription Duration

   As profiles are generally static with infrequent changes, it is attempted.

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4.3 Multicast
   recommended that default subscription duration be 86400 seconds (one
   day).

3.5 NOTIFY Bodies

   The enrollment request size of profile content is sent likely to be hundreds to several
   thousand bytes in size.  Frequently even with very modest sized SDP
   bodies, SIP messages get fragmented causing problems for many user
   agents.  For this reason the multicast address NOTIFY body MUST use content indirection
   [I-D.ietf-sip-content-indirect-mech] for SIP
   registration [6] "sip.mcast.net" (224.0.1.75).  If a server does not
   respond with a successful 2xx class response to providing the enrollment
   request, profiles.

   The profile delivery server MUST include the next discovery mechanism Content-ID defined in
   [I-D.ietf-sip-content-indirect-mech] for each profile URL.  This is attempted.

4.4 Manually Provisioned

   The UA MAY indicate
   to avoid unnecessary download of the profiles.  Some user (or administrator) that automatic
   discovery has failed. The UA SHOULD allow the user or administrator agents are
   not able to manually (perhaps using some out of band method e.g. beam, smart
   card, etc.) enter the configuration server address and port make a profile effective without rebooting or restarting.
   Rebooting is probably something to be
   used for enrollment.

5  Enrollment and Change Notification

   The enrollment and configuration change notification are paired
   together and provided via avoided on a user agent
   performing services such as telephony.  In this way the SIP SUBSCRIBE/NOTIFY framework [7].
   This document defines Content-ID
   allows the profile on top user agent to avoid unnecessary interruption of service as
   well.  The Content-Type MUST be specified for each URL.

      Initially it is expected that most user agent vendors will use a
      proprietary content type for the SUBSCRIBE/NOTIFY
   framework [7] profiles retrieved from the
      URLs(s).   It is hoped that over time a standard content type will
      be specified that will be adopted by vendors of user agents.  One
      direction that appears to be promising for this purpose.

   UA enrollment with the configuration server content is accomplished via the
   SUBSCRIBE request.  A UA MUST enroll to use
      XML with the configuration server
   prior name spaces [??] to retrieving configuration data profiles.  As part of the
   enrollment segment the UA MUST identify itself, its configuration retrieval
   protocol capabilities and configuration data profile requirements.

   The configuration server into sets that the
      user agent implementer may use this information to decide how to
   allocate resources (e.g. load balancing) choose to support the UA for its
   specific configuration retrieval needs. based upon desired
      feature set.  The configuration server
   may also use specification of the UA enrollment event as content is out of the trigger to generate a
   new set scope
      of configuration data for this document.

   Likewise the specific UA (e.g. based upon
   provisioned defaults and configuration profile context knowledge for URL scheme used in the environment).  This allows content indirection is outside
   the configuration server scope of this document.  This document is agnostic to provide
   configuration data for a new UA without previously provisioning the
   specific UA on URL
   schemes as the server.

   Each profile that the device requires content may dictate what is obtained via a separate
   enrollment or SUBSCRIBE request and SIP dialog.  That required.  It is
   expected that  TFTP [RFC3617], FTP [??], HTTP [RFC2616], HTTPS
   [RFC2818], LDAP [RFC3377], XCAP [I-D.rosenberg-simple-xcap] and other
   URL schemes are supported by this package and framework.

3.6 Notifier processing of SUBSCRIBE requests

   The general rules for each
   different profile a device enrolls for, a different Call-Id is used. processing SUBSCRIBE requests [RFC3265] apply
   to this package.  The device names notifier does not need to authenticate the
   subscription as the profile MIME type content is not transported in the
   SUBSCRIBE Accept
   header field.  The configuration server then delivers a URL (through
   content indirection [15]) at or NOTIFY transaction messages.  Only URLs are transported
   in the NOTIFY request which may be secured using the device can retrieve techniques in
   section Section 6.

   The behavior of the profile in delivery server is left to the
   implementer.  The profile delivery server may be as simple as a subsequent SIP
   SUBSCRIBE UAS and NOTIFY request.  Changes UAC front end to a simple HTTP server
   delivering static files that are hand edited.  At the other extreme
   the profile delivery server can be part of a configuration management
   system that integrates with a corporate directory and IT system or
   carrier OSS, where the profiles are
   indicated in additional NOTIFY requests sent automatically generated.  The
   design of this framework intentionally provides the flexibility of
   implementation from simple/cheap to complex/expensive.

   If the configuration
   server.

   The SUBSCRIBE request for enrollment user or device is sent not known to the address(es)
   identified in profile delivery server,
   the discovery process until implementer MAY accept the first successful 2xx
   class response subscription or reject it.  It is received.  As part of
   recommended that the binding of implementer accept the
   SUBSCRIBE/NOTIFY framework a new MIME type must be named for each

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   type of profile.  The profile(s) MIME type(s) MUST be included in the SUBSCRIBE Accept header field.

   [Is it ok profile delivery server to maintain the subscription
   as an administrator may add the user or device to the system,
   defining the profile contents.  This allow a single SUBSCRIBE the profile delivery
   server to immediately send a NOTIFY request multiple with the profile
   types in (e.g. for each MIME subtype application/sip-ua-user-profile
   and application/sip-ua-device-profile)?] URLs.
   If enrollment fails (i.e. no 2xx response to SUBSCRIBE), the UA
   SHOULD re-discover the configuration profile delivery server address does not accept the subscription from
   an unknown user or device, the administer or user must manually
   provoke the user agent to reSUBSCRIBE.  This may be difficult if the
   user agent and port as
   described administrator are at different sites.

3.7 Notifier generation of NOTIFY requests

   As in section 3.

5.1 SUBSCRIBE

   The SUBSCRIBE [RFC3265], the profile delivery server MUST always send a
   NOTIFY request is used by upon accepting a subscription.  If the UA device or user
   is unknown to enroll in the
   configuration domain of profile delivery server and it chooses to accept
   the configuration server.  It uniquely
   identifies subscription, the UA implementer has two choices.  A NOTIFY MAY be
   sent with vendor, model and serial number information.
   The UA also MUST specify its capabilities for configuration
   retrieval. The UA MUST indicate support for no body or content indirection by
   including containing the MIME type message/external-body in profile
   URL(s).  Alternatively a NOTIFY MAY be sent with URL(s) pointing to a
   default data set.  Typically this data set allows for only limited
   functionality of the SUBSCRIBE
   Accept header field per [15].

   The configuration user agent (e.g. a phone user agent with data to
   call help desk and emergency services.).  This is an implementation
   and business policy decision.

   A user or device known and fully provisioned on the profile delivery
   server SHOULD not send an error if it is
   temporarily not able to provide a NOTIFY with content indirection containing URLs
   for all of the configuration data profile
   listed profiles associated with the user or device (i.e.
   which ever specified in the SUBSCRIBE request Event header field.  In profile-type parameter).  The device may
   be associated with a default user.  The URL(s) for this default user
   profiles MAY be included with the first
   time out URL(s) of the box case, device if the profile
   type specified is device.

   A user agent can provide Hoteling by collecting a userĺs AOR and
   credentials needed to SUBSCRIBE dialog may be and retrieve the only means
   of communicating with user profiles from
   the device as it does not yet have
   configuration.  The configuration server SHOULD send URL(s).  Hoteling functionality is achieved by subscribing to the
   AOR and specifying the "user" profile type.  This same mechanism can
   be used to secure a user agent, requiring a 403 response
   to the SUBSCRIBE if is not willing user to provide the requested
   configuration profile login to enable
   functionality beyond the device. default userĺs restricted functionality.

   The configuration server
   SHOULD provide the configuration data profile to delivery server MAY specify when the UA via content
   indirection.  If new profiles MUST be
   made effective by the configuration server sends a 301 Moved
   Permanently response to user agent.  By default the enrollment SUBSCRIBE, user agent makes
   the UA SHOULD
   cache profiles effective as soon as it thinks that it is non-obtrusive.

   However the URL contained profile delivery server MAY specify a maximum time in the response Contact header field
   seconds (zero or more), in
   place of the address and port found during discovery for future
   enrollment.

        The device may request many configuration data profiles effective-by event header parameter,
   by
        sending multiple SUBSCRIBE requests each in a different SIP
        dialog.  This may be useful if which the device requires user
        specific agent MUST make the new profiles for multiple users.  In effective.

3.8 Subscriber processing of NOTIFY requests

   The user agent subscribing to this case event package MUST adhere to the
        UserProfile parameter would vary for each SUBSCRIBE.
        Alternately
   NOTIFY request processing behavior specified in [RFC3265].  The user
   agent MUST make the device may require multiple types of profiles
        where each SUBSCRIBE would have a different MIME type effective as specified in the
        Accept header field. NOTIFY
   request (see section Section 3.7).  The configuration server MAY user agent SHOULD use one of
   the enrollment (SUBSCRIBE request)
   as the stimulus techniques specified in section [RFC3265] to generate a new instance securely retrieve
   the profiles.

3.9 Handling of forked requests

   This event package allows the creation of only one dialog as a configuration data
   profile unique result
   of an initial SUBSCRIBE request.  The techniques to achieve this are
   described in section 4.4.9 of [RFC3265].

3.10 Rate of notifications

   It is anticipated that the rate of change for user and device
   profiles will be very infrequent (i.e. days or weeks apart).  For
   this reason no throttling or minimum period between NOTIFY requests
   is specified for this package.

3.11 State Agents

   State agents are not applicable to the UA.  Alternately the configuration server MAY
   be provisioned ahead this event package.

3.12 Examples

   SUBSCRIBE sip:00df1e004cd0@example.com SIP/2.0
   Event: sip-profile;profile-type=device;vendor=acme;
                            model=Z100;version=1.2.3
   From: sip:00df1e004cd0@acme.com;tag=1234
   To: sip:00df1e004cd0@acme.com;tag=abcd
   Call-ID: 3573853342923422@10.1.1.44
   CSeq: 2131 SUBSCRIBE
   Contact: sip:00df1e004cd0@10.1.1.44
   Content-Length: 0

   NOTIFY sip:00df1e004cd0@10.1.1.44 SIP/2.0
   Event: sip-profile;effective-by=3600
   From: sip:00df1e004cd0@acme.com;tag=abcd
   To: sip:00df1e004cd0@acme.com;tag=1234
   Call-ID: 3573853342923422@10.1.1.44
   CSeq: 321 NOTIFY
   MIME-Version: 1.0
   Content-Type: multipart/mixed; boundary=boundary42
   Content-Length: ...

   --boundary42
   Content-Type: message/external-body;
       access-type="URL";
       expiration="Mon, 24 June 2002 09:00:00 GMT";
           URL="http://www.example.com/devices/fsmith";
           size=2222

   Content-Type: application/z100-user-profile
   Content-ID: <69ADF2E92@example.com>

   --boundary42
   Content-Type: message/external-body;
       access-type="URL";
       expiration="Mon, 24 June 2002 09:00:00 GMT";
           URL="http://www.example.com/devices/ff00000036c5";
           size=1234

   Content-Type: application/z100-device-profile
   Content-ID: <39EHF78SA@example.com>

   --boundary42--

3.13 Use of time URIs to know about new UAs and their
   specific configuration data content (for example based upon serial
   number, MAC address).

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                       User Agent Configuration Retrieve State

   The user agent forms the From field profile type specified determines what goes in the SUBSCRIBE in one user part of two
   ways depending upon
   the type of SUBSRIBE URI.  If the profile that it type requested is enrolling to.  If "device", the
   user agent part is enrolling to a device specific profile, the an identity that MUST be unique across all user agents
   from
   addr-spec is formed as: sip:<MAC-address>@<local-domain>.  If all vendors.  This identity must be static over time so that the
   profile delivery server can keep it associated with its profiles.
   For Ethernet hardware type user agent is enrolling to agents supporting only a single user specific profile the addr-spec
   at a time this is
   formed as most easily accomplished using its MAC address.
   Software based user agents running on general purpose hardware may
   also be able to use the users MAC address for identity.  However in
   situations where multiple instance of record.  In this way user agents are running on the identity
   same hardware it may be necessary to use a another scheme, such as
   using a unique serial number for
   which the software.

   If the profile type request is desired is always specified in the From field.

5.1.1   Additional User Agent Field Parameters

   When "user" the device first starts up out of URI in the box, it has no user or
   local configuration.  The device MUST provide a unique identity such
   that it SUBSCRIBE
   request is possible the address of record for the configuration server user.   This allows the user
   to specify (e.g. login) to generate
   configuration profile for the device.  The user agent MUST include
   the User-Agent header in the SUBSCRIBE request. by simply entering their
   known identity.

4. Profile Delivery Framework Details

   The following
   additional User-Agent field parameters are describes how different functional steps of the profile
   delivery framework work.  Also described here is how the event
   package defined for in this document provides the purpose
   of identifying enrollment and
   notification functions within the UA device:

   Vendor ű a token used framework.

4.1 Discovery of Subscription URI

   The discovery function is needed to identify the UA vendor name

   Model ű a token used bootstrap user agents to identify the UA hardware/software model

   Version ű a token used
   point of knowing where to identify the firmware/software version
   currently installed on enroll with the UA

   Serial ű profile delivery server.
   Section Section 3.13 describes how to form the token URI used to identify sent the serial number
   SUBSCRIBE request for enrollment.  However the bootstrapping problem
   for the UA

        Note: on some hardware such as PCs and servers, there may be
        multiple instances of a user agent installed.  In these
        scenarios only the serial number can be used to uniquely
        distinguish instances.

   Mac ű (out of the token used box) is what to identify the MAC address in hex use for the UA

   From RFC 3261 [6] the User-Agent header field syntax is extended to:
   User-Agent  =  "User-Agent" HCOLON product *( SEMI config-params )

   config-params = serial-param / mac-param / generic-param
   product          =  vendor-model [SLASH product-version]
   product-version  =  token
   vendor-param  =  ˘Vendor÷ ˘=÷ token
   serial-param  =  ˘Serial÷ ˘=÷ token
   mac-param  =  ˘Mac÷ ˘=÷ token

   Example:
   User-Agent: model-a/1.5.0.1;vendor=acme

   The Vendor, Model, Version, Serial host and Mac parameters MUST be
   provided
   port in the User-Agent header field for URI.  Due to the wide variation of environments in which
   the enrollment SUBSCRIBE

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   request.  Most profiles will either be device or user specific.  All
   config-params MUST be specified even when enrolling for user
   profiles as the device characteristics agent may impact reside (e.g. behind residential router,
   enterprise LAN, ISP, dialup modem) and the content limited control that the
   administrator of the profile delivery server provides.

5.2 NOTIFY (e.g. enterprise,
   service provider) may have over that environment, no single discovery
   mechanism works everywhere.  Therefore a number of mechanisms SHOULD
   be tried in the specified order: SIP DHCP option [RFC3361], SIP DNS
   SRV [RFC3263], DNS A record and manual.

   1.  The NOTIFY message first discovery mechanizm that SHOULD be tried is sent by the configuration server to convey
       construct the
   URL at which SUBSCRIBE URI as described in Section 3.13 using
       the UA can retrieve host and port of out bound proxy discovered by the requested configuration data
   profile.  This occurs SIP DHCP
       option as described in two contexts:

     Immediately following [RFC3361].  If the enrollment SUBSCRIBE SIP DHCP option is not
       provided in the configuration
     server MUST send DHCP response, no SIP response or a NOTIFY providing SIP failure
       response other than for authorization is received for the URL
       SUBSCRIBE request to the sip-profile event, the next discovery
       mechanism SHOULD be tried.
   2.  The local IP network domain for the configuration
     data profile requested by user agent, either configured
       or discovered via DHCP, should be used with the UA technique in
       [RFC3263] to obtain a host and port to use in the Event header field of the SUBSCRIBE request. URI.
       If the configuration server no SIP response or a SIP failure response other than for
       authorization is not able received for the SUBSCRIBE request to
     provide the specific configuration data profile or it does not
     want
       sip-profile event, the UA to retrieve next discovery mechanism SHOULD be tried.
   3.  The fully qualified host name constructed using the specific configuration profile at that
     time, it MAY defer sending NOTIFY.  Later when host name
       "sipuaconfig" and concatenated with the configuration
     server is able local IP network domain
       should be tried next using the technique in [RFC3263] to provide obtain a
       host and port to use in the data profile SUBSCRIBE URI.  If no SIP response or it wishes
       a SIP failure response other than for authorization is received
       for the UA SUBSCRIBE request to
     retrieve the data profile, sip-profile event, the configuration server MAY send a
     NOTIFY request containing next
       discovery mechanism SHOULD be tried.
   4.  If all other discovery techniques fail, the URL user agent MUST
       provide a manual means for the configuration data
     profile which user to enter the UA SHOULD retrieve host and make effective as soon as
     it is safe port
       used to do so (e.g. when there are no active INVITE
     dialogs).

     If construct the configuration server becomes aware of SUBSCRIBE URI.

   Once a configuration
     change that it wishes to be effective immediately on the UA, the
     configuration server SHOULD send user agent has successfully discovered, enrolled, received a
   NOTIFY message containing response with profile URL(s), the
     URL for user agent SHOULD cache the configuration data profile that
   SUBCRIBE URI to avoid having to rediscover the UA requested when
     it enrolled.  The configuration data profile with changed content
     SHOULD have a different Content-ID entity header than that of delivery
   server again in the
     last NOTIFY request. future.  The UA user agent SHOULD retrieve and make effective
     the changed configuration URL immediately upon receipt of NOT cache the
   SUBSCRIBE URI until it receives a NOTIFY request. with profile URL(s).  The UA MAY choose to wait to make the changes
     effective (e.g. to prevent the change from disrupting active calls
     on the UA).

     [Do we need an option
   reason for the configuration this is that a profile delivery server may send 202
   responses to SUBSCRIBE requests and NOTIFY responses to tell unknown user
   agent (see section Section 3.6) with no URLs.  Until the UA
     that profile
   delivery server has sent a NOTIFY request with profile URL(s), it MUST make has
   not agreed to provide profiles.

      To illustrate why the change immediately regardless of state?
     Should this be user agent should not cache the default?]

   The UA SHOULD send a 200 response to SUBSCRIBE
      URI until profile URL(s) are provided in the NOTIFY immediately upon
   receipt and validation of NOTIFY, consider the solicited request.
      following example:  a user agent running on a laptop plugged into
      a visited LAN in which a foreign profile delivery server is
      discovered.  The configuration profile delivery server MUST include, never provides profile
      URLs in the change notification NOTIFY request, request as it is not provisioned to accept the
   configuration data profile URL.
      user agent.  The Content-ID entity header
   associated with user then takes the configuration data profile with changed content
   should be different than that of laptop to their enterprise
      LAN.  If the previous NOTIFY.
     This mechanism may be used by user agent cached the configuration SUBSCRIBE URI from the visited
      LAN (which did not provide profiles), the user agent would not
      attempt to discover the profile delivery server in the enterprise
      LAN which is provisioned to provide
     firmware updates.  For example on a UA that caches or has a
     persistent firmware image: if profiles to the server realizes (e.g. from user agent..

4.2 Enrollment with Profile Server

   Enrollment is accomplished by subscribing to the event package
   described in section Section 3.  The enrollment information) the UA process is running useful to
   the most currently
     available firmware version, profile delivery server as it could defer sending the NOTIFY with makes the URL for server aware of user
   agent to which it may delivery profiles (those user agents the firmware.  However at a later time when a new

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     firmware version
   profile delivery server is available provisioned to provide profiles to; those
   present that the configuration server could send
     a NOTIFY with the URL for may be provide profiles in the new firmware version, indicating future; and
   those that the
     UA SHOULD upgrade as soon as it server can automatically provide default profiles).
   It is safe an implementation choice and business policy as to do so.

5.2.1   NOTIFY Body Content Format

The NOTIFY request MUST contain a single part body with content
indirection [15].  The request MUST have a Content-Type header field
with the MIME type of message/external-body.  The Content-Type MUST
also have a URL parameter specifying whether the URL at which
   profile delivery server provides profiles to retrieve the
profile.  The body MUST contain a Content-Type entity header with user agents that it is
   not provisioned to do so.  However the
MIME type profile server SHOULD accept
   (with 2xx response) SUBSCRIBE requests from any user agent.

4.3 Notification of Profile Changes

   The NOTIFY request in the profile as sip-profile event package server two
   purposes.  First it provides the value.  The body MUST also contain user agent with a
Content-ID entity header which SHOULD change means to a new unique value each
time the content of obtain
   the URL changes.    The Content-ID entity header
associated with URL(s) for desired profiles without requiring the URL is intended end user to allow
   manually enter them.  It also provides the UA means for the profile
   delivery server to decide if it has notify the user agent that the latest content of the configuration data profile without having to
download
   profiles have changed and compare the contents.

   Example:

   NOTIFY sip:00df1e004cd0@acme.com SIP/2.0
   From: sip:sipuaconfig@sipuaconfig.acme.com;tag=1234
   To: sip:00df1e004cd0@acme.com;tag=abcd
   Call-ID: 3573853342923422@10.1.1.123
   CSeq: 2131 INVITE
   Content-Type: message/external-body;
                 ACCESS-TYPE=URL;
                 URL="https://acme.com/profiles/vendor-x/00df1e004cd0"
   Content-Length: ...
   Content-Type: application/foo-profile
   Content-Disposition: session
   Content-ID: <1000957853@acme.com>

6  Configuration should be made effective.

4.4 Retrieval of Profile Data

   The UA MUST retrieve its configuration data profile using the URL
   specified by user agent retrieves it's needed profile(s) via the configuration server URL(s)
   provide in the NOTIFY request.  If request as specified in section Section 3.5.
   The profile delivery server SHOULD secure the
   retrieval fails, content of the UA profiles
   using one of the techniques described in Section 6.  The user agent
   SHOULD not re-enroll until make the SUBSCRIBE
   session expires to avoid a cascade effect if new profiles effective in the server goes down
   temporarily. timeframe described in
   section Section 3.2.

   The device MAY re-try the profile retrieve contents of the
   profile from the URL before the SUBSCRIBE expires. Should profiles SHOULD be cached by the re-
   enrollment fail, user agent.
   This it to avoid the UA SHOULD re-discover situation where the configuration content delivery server
   as described in section 4.

7  Configuration Upload

   If is
   not available, leaving the UA user agent non-functional.

4.5 Upload of Profile Changes

   The user agent or another entity wishes to modify a configuration data
   profile it other service MAY make the change persistent on push changes up to the configuration profile
   delivery server if it is authorized using the technique appropriate to do so. the profile's URL
   scheme (e.g. HTTP PUT method, FTP put command).  The configuration server
   SHOULD support technique for
   pushing incremental or atomic changes MUST be described by the ability to accept uploads
   specific profile data framework.

5. IANA Considerations

   [TBD]

6. Security Considerations

   Profiles may contain sensitive data such as user credentials.  The
   protection of this data is accomplished via the same URL profile retrieval
   function.  This simplifies the UA
   used security solution as the SIP event
   package does not need to retrieve authenticate, authorize or protect the configuration data profile.  For HTTP and HTTPS
   contents of the UA does a POST with a multipart MIME attachment containing SIP messages.  Effectively the profile delivery
   server will provide profile URL(s) to any
   URL parameters in one part one.  The URLs themselves
   are protected via authentication, authorization and the changed configuration data

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   profile [whole or changes only ?? define in secure retrieval of profiles ??] in another
   part as defined in [?].  If the UA or user are follow:

6.1 Symmetric Encryption of Profile Data

   One security technique is not permitted to make encrypted the changes profiles on the configuration content
   delivery server using the configuration server
   returns an HTTP error response code AES symmetric encryption algorithm using a
   key formed by a MD5 hash of 403 Forbidden.  If the
   configuration following: username ":" password.
   The encrypted profiles are delivered by the content delivery server returns a 403
   via the UA SHOULD disallow URLs provided in the
   changes from being effective on NOTIFY requests.  Using this technique
   the UA.   The UA SHOULD profile delivery server does not make the
   changes effective until it receives a successful response (e.g. need to provide authentication
   or authorization for
   HTTP 2xx).

   If the URL retrieval as the profiles are obscured.  The
   user agent must obtain the username and password from the user to
   generate the key and perform AES decryption the profiles.  This is for HTTP/HTTPS
   the simplest security technique as it does not require any public key
   infrastructure or TLS implementation on the user agent (which often
   has limited resources).

6.2 Client Certificate Authentication with HTTPS

   In another technique the content delivery server MUST return authenticates the changed
   configuration data profile
   user or user agent by requesting the client's certificate in the response (assuming it was
   allowed). The UA SHOULD use TLS
   connection established as described by the configuration data profile contents
   from URL.  The content
   delivery server authorizes the HTTP response as opposed to profile retrieval using the data that was pushed in
   certificate identity and business policy choices provide by the
   request as changes may occur from other sources.  The
   server SHOULD
   include a Content-ID header in the HTTP/HTTPS response. implementer. The
   configuration server SHOULD send out a NOTIFY for this change, profile data is obscured from snooping using
   the same Content-ID entity header value as in encryption mechanisms provide by the HTTP/HTTPS
   response. TLS connect.  This allows has nice
   properties of not requiring end user intervention, but has a higher
   administrative cost for user agent certificate management and
   distribution.  It also requires the UA certificates to know that it already has be in place
   before enabling profile delivery.

6.3 HTTPS Authentication

   Alternatively the current
   contents of authentication mechanizms described in [RFC2617]
   are used.  The content delivery server authorizes the configuration data profile
   retrieval using the certificate identity and SHOULD not download
   that configuration data business policy choices
   provide by the server implementer. The profile (i.e. it data is safe to ignore obscure from
   snooping using the
   NOTIFY as encryption mechanisms provide by the Content-ID is TLS connect.
   This also requires the same).

   [Alteratively overhead of a TLS implementation on the Content-ID could be put user
   agent.

   For all of these techniques the user agent should take care in how it
   stores or caches the content profiles to avoid theft.  It is recommended that
   a symmetric encryption technique such as opposed that described in section
   Section 6.1 be used.  This also requires the overhead of a TLS
   implementation on the user agent.

7. Differences from Simple XCAP Package

   The author of this document had an action item from the July 2003
   IETF SIPPING WG meeting to consider resolving the HTTP/HTTPS response]

   [TBD ű in 403 case restrict differences of the
   sip-profile and provide feedback as to what
   specifically simple XCAP package [I-D.ietf-simple-xcap-package].
   It is not allowed to the author's opinion that XCAP [I-D.rosenberg-simple-xcap] can
   be modified supported by the UA or user]

8  Examples

   Below framework and event package defined in this
   document as it is an example high level message flow for simply a new UA discovering
   and URL using configuration data from a configuration server.  Following the high level message flows are some specific SIP messages
   illustrating SUBSCRIBE and NOTIFY messages from enrollment and
   configuration change notification.

8.1 Example Message Flows HTTP or HTTPS scheme.  The
   following high level message flows illustrate lists the configuration
   process of discovery, enrollment, configuration retrieval and change
   notification with associated configuration retrieval.  The UA uses
   DHCP with differences between the SIP [3] option requesting event packaged defined in
   this document vs. the configuration server
   address and port. one defined in [I-D.ietf-simple-xcap-package].

   The DHCP server does not provide simple XCAP package requires that the
   configuration server address or port. relative path be known and
   specified by the user agent when subscribing for change notification.
   The UA then does event package in this document requires a DNS lookup
   for the configuration service within token be known and
   specified when subscribing.  The advantage of the local domain. latter is that
   bootstrapping is easier and well defined.  It gets a
   response from also leaves the DNS server for freedom
   of specifying the configuration serverĂs fully
   qualified host name.  The UA then enrolls with entire path of the configuration
   server by sending a SUBSCRIBE request for profile URL up to the profile type indicated
   delivery server.

   The event package defined in this document allows multiple URLs to be
   provided in the Event header.  The configuration server sends back a
   successful response.  The configuration server then sends a NOTIFY request with body as a result of a single token
   specified in the URL for SUBSCRIBE event parameter: profile-type.  This
   allows the configuration data profile delivery server to provide sets of profiles that
   the UA
   named user agent may not have enough information to specify in the enrollment
   SUBSCRIBE request.  The UA sends a 200
   response to URI (e.g. at boot strapping time the NOTIFY.  The UA then downloads user agent may not
   know the configuration

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                         A Framework user's identity, but the profile delivery server may know
   the default user for SIP                Feb. 2003
                       User Agent Configuration

   data the device's identity) or the doc-component of
   the simple XCAP package.

   The simple XCAP package provides profile via data changes or deltas in
   the URL from body of the NOTIFY request.  This process may
   be repeated is a desirable feature, but
   approach in parallel for each of the required profiles.  The UA
   is now configured as prescribed.

   Later ... an administrator makes simple XCAP package has a change few disadvantages:

   o  SIP signaling requires authentication, authorization and
      encryption (SIPS) to protect the configuration for profiles where the UA event package
      in this document does not.  SIPS may require more resources than
      are available on the configuration server. many user agents.
   o  The configuration server on
   behalf content of the administrator, sends a NOTIFY (change notification)
   request to the UA with Content-ID entity header for the profile.  As
   the Content-ID value has changed, the UA downloads the configuration
   data profile from change may be large, causing
      fragmentation and problems or constraints when using UDP.

   The feature of providing profile data changes or deltas can be
   provided in the given URL.

   UA           DHCP Server     DNS Server      Config. Server

   Discovery

   IP config. req.
   ==============>
   IP config. wo/ local option
   <==============
   DNS A record req. for sipuaconfig host package proposed in local domain
   =============================>
   A record IP address returned for Host
   <=============================

   Enrollment

   SIP SUBSCRIBE Event: sip-config
   ==================================================>
   200 OK
   <==================================================
   SIP this document by providing two
   URLs in the NOTIFY Event: sip-config w/ requested request for each profile (i.e. a URL
   <==================================================
   200 OK
   ==================================================>

   Configuration retrieval

   HTTP GET
   ==================================================>
   200 OK (specific profile data in body)
   <==================================================
   .
   .
   .

   Administrative change on configuration server via user interface
   .
   .
   .

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                         A Framework for SIP                Feb. 2003
                       User Agent Configuration

   Change Notification

   SIP NOTIFY Event: sip-config w/ changed the
   complete profile URL
   <==================================================
   200 OK
   ==================================================>
   HTTP GET
   ==================================================>
   200 OK (profile data and another for the changes).

   All other functional differences between
   draft-ietf-sipping-config-framework-00 and
   draft-ietf-simple-xcap-package-00 are believed to be resolved in body)
   <==================================================
   .
   .
   .

   User changes data this
   version of this document.

8. Open Issues

9. Change History

9.1 Changes from draft-ietf-sipping-config-framework-00.txt

   This version of the document was entirely restructured and re-written
   from the previous version as it had been micro edited too much.

   All of the aspects of defining the event package are now organized in
   one section and is believed to be complete and up to date with
   [RFC3265].

   The URI used to subscribe to the event package is now either the user
   or device address or record.

   The user agent information (vendor, model, MAC and serial number) are
   now provided as event header parameters.

   Added a mechanism to force profile on changes to be make effective by
   the user agent
   .
   .
   .

   Configuration Upload

   HTTP POST (changed profile attached as multipart MIME)
   ==================================================>
   200 OK (profile data in body, as change confirmation)
   <==================================================
   .
   .
   .

8.2 Example Messages

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                         A Framework for SIP                Feb. 2003
                       User Agent Configuration

   The following SUBSCRIBE request example is from a UA enrolling specified maximum period of time.

   Changed the name of the event package from sip-config to sip-profile

   Three high level securityapproaches are now specified.

9.2 Changes from draft-petrie-sipping-config-framework-00.txt

   Changed name to reflect SIPPING work group item

   Synchronized with
   a configuration server.  As this SUBSCRIBE request is for
   configuration enrollment changes to SIP DHCP [RFC3361], SIP [RFC3261] and
   [RFC3263], SIP Events [RFC3265] and content indirection
   [I-D.ietf-sip-content-indirect-mech]

   Moved the Event header device identity parameters from the From field contains parameters
   to User-Agent header parameters.

   Many thanks to Rich Schaaf of Pingtel, Cullen Jennings of Cisco and
   Adam Roach of Dyamicsoft for the token
   sip-config.  The UA tells great comments and input.

9.3 Changes from draft-petrie-sip-config-framework-01.txt

   Changed the configuration server that it would
   like name as this belongs in the configuration data profile SIPPING work group.

   Minor edits

9.4 Changes from draft-petrie-sip-config-framework-00.txt

   Many thanks to those who contributed and commented on the previous
   draft.  Detailed comments were provided by Henning Schulzrinne from
   Columbia U., Cullen Jennings from Cisco, Rohan Mahy from Cisco, Rich
   Schaaf from Pingtel.

   Split the enrollment into a single SUBSCRIBE dialog for each profile.
   The 00 draft sent a single SUBSCRIBE listing all of type: sip-ua-device-config in
   the Accept header field.  The UA tells the configuration server desired.
   These have been split so that
   it each enrollment can be routed
   differently.  As there is enrolling for 86400 seconds via the Expires header field.
   During this period a concept of time the configuration server MUST send device specific and

   user specific profiles, these may also be managed on separate
   servers.  For instance in a
   change notification  with the URL for roaming situation the configuration data device might get
   it's profile data from a local server which changed.  The UA has identified the specifics about itself in
   the From field addr-spec and User-Agent parameters: Vendor/Model,
   Version, Serial, Mac.  In this example the UserProfile parameter is
   not included in the From field as knows the sip-config profile is device LAN specific not user specific.

   UA => Config. Server

   SUBSCRIBE sip: sipuaconfig@config.localdomain.com SIP/2.0
   To: sip:sipuaconfig@sipuaconfig.localdomain.com
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   User-Agent: acme-model-a/1.5.0.1;Serial=1234567890;Mac=000aaa1234cd
   Call-Id: 987654321@10.1.1.123
   Cseq: 1 SUBSCRIBE
Event: sip-config
   Expires: 86400
   Content-Length: 0
   Accept: message/external-body application/sip-ua-device-config

   The following is an example response to the above enrollment
   request.

   Config. Server => UA

   SIP/2.0 202 Accepted
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=owiu1234
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   Call-Id: 987654321@10.1.1.123
   Cseq: 1 SUBSCRIBE
   Content-Length: 0

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                         A Framework for SIP                Feb. 2003
                       User Agent Configuration

   In
   profile data.  At the following example same time the device is requesting a user specific
   profile Sip-User.  The device specifies that it want profiles might come
   from the user's home environment profile for delivery server.

   Removed the user: sip:fredsmith@localdomain.com.

   UA => Config. Server

   SUBSCRIBE sip: sipuaconfig@sipuaconfig.localdomain.com SIP/2.0
   To: sip:sipuaconfig@sipuaconfig.localdomain.com
   From: sip:fredsmith@localdomain.com;tag=klhfkjncd
   User-Agent: acme-model-a/1.5.0.1;Serial=1234567890;Mac=000aaa1234cd
   Call-Id: 11111111@10.1.1.123
   Cseq: 1 SUBSCRIBE
   Event: sip-config
   Expires: 86400
   Content-Length: 0
   Accept: message/external-body application/sip-ua-user-config

   The following Config-Expires header as it is an example response to largely superfluous with
   the above enrollment
   request.

   Config. Server => UA

   SIP/2.0 202 Accepted
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=oqieu983
   From: sip:fredsmith@localdomain.com;tag=klhfkjncd
   Call-Id: 11111111@10.1.1.123
   Cseq: 1 SUBSCRIBE
   Content-Length: 0

   The following example is the immediate NOTITY request the
   configuration server sent to Expires header.

   Eliminated some of the UA above enrollment.  The URL complexity in the request body is for the configuration data discovery mechanism.

   Suggest caching information discovered about a profile delivery
   server to avoid an avalanche problem when a whole building full of
   devices powers up.

   Added the UA named
   in the Event User-Profile From header field in parameter so that the above SUBSCRIBE device
   can a request a user specific profile for a user that is different
   from the
   UA.

   Config. Server => UA

   NOTIFY sip:10.1.1.123 SIP/2.0
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=owiu1234
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   Call-Id: 987654321@10.1.1.123
   Cseq: 22 NOTIFY
   Event: sip-config
   Content-Type: message/external-body;ACCESS-TYPE=URL;
     URL="http://config.localdomain.com/device/000aaa1234cd/dev-prof
   Content-Length: ...

   Content-Type: application/sip-ua-device-config
   Content-ID: 000aaa1234cd-3254@localdomain.com

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                         A Framework device's default user.

References

   [I-D.ietf-simple-xcap-package]
              Rosenberg, J., "A Session Initiation Protocol (SIP) Event
              Package for Modification  Events for the Extensible Markup
              Language (XML) Configuration Access Protocol (XCAP)
              Managed Documents", draft-ietf-simple-xcap-package-00
              (work in progress), June 2003.

   [I-D.ietf-sip-content-indirect-mech]
              Olson, S., "A Mechanism for Content Indirection in Session
              Initiation Protocol (SIP)  Messages",
              draft-ietf-sip-content-indirect-mech-03 (work in
              progress), June 2003.

   [I-D.ietf-sipping-ua-prof-framewk-reqs]
              Petrie, D. and C. Jennings, "Requirements for SIP                Feb. 2003 User
              Agent Profile Delivery Framework",
              draft-ietf-sipping-ua-prof-framewk-reqs-00 (work in
              progress), March 2003.

   [I-D.rosenberg-simple-xcap]
              Rosenberg, J., "The Extensible Markup Language (XML)
              Configuration

   The following is an example response from the UA Access Protocol  (XCAP)",
              draft-rosenberg-simple-xcap-00 (work in progress), May
              2003.

   [I-D.sinnreich-sipdev-req]
              Butcher, I., Lass, S., Petrie, D., Sinnreich, H. and C.
              Stredicke, "SIP Telephony Device Requirements,
              Configuration and Data", draft-sinnreich-sipdev-req-02
              (work in progress), October 2003.

   [RFC0822]  Crocker, D., "Standard for the above
   request.

   UA => Config. Server

   SIP/2.0 200 Ok
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=owiu1234
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   Call-Id: 987654321@10.1.1.123
   Cseq: 22 NOTIFY
   Content-Length: 0

   Assume at some later time, an administrator makes a change to the
   content format of the sip-config configuration data profile for the UA.
   The configuration server sends a NOTIFY request to the UA ARPA Internet
              text messages", STD 11, RFC 822, August 1982.

   [RFC2119]  Bradner, S., "Key words for the
   configuration change notification.  This example request below
   indicates the changed URL or content use in the request body with a
   higher sequence number.

   Config. Server => UA

   NOTIFY sip:10.1.1.123 SIP/2.0
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=owiu1234
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   Call-Id: 987654321@10.1.1.123
   Event: sip-config
   Cseq: 23 NOTIFY
   Content-Type: message/external-body;ACCESS-TYPE=URL;
     URL="http://config.localdomain.com/device/000aaa1234cd/dev-prof
   Content-Length: ...

   Content-Type: application/sip-ua-device-config
   Content-ID: 000aaa1234cd-3255@localdomain.com

   The following is an example response to the above request.

   UA => Config. Server

   SIP/2.0 200 Ok
   To: sip:sipuaconfig@sipuaconfig.localdomain.com;tag=owiu1234
   From: sip:000aaa1234cd@localdomain.com;tag=aslkjhd
   Call-Id: 987654321@10.1.1.123
   Cseq: 23 NOTIFY
   Content-Length: 0

9  Security Considerations

   [This section needs RFCs to be greatly expanded Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2131]  Droms, R., "Dynamic Host Configuration Protocol", RFC
              2131, March 1997.

   [RFC2132]  Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
              Extensions", RFC 2132, March 1997.

   [RFC2246]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A.
              and P. Kocher, "The TLS Protocol Version 1.0", RFC 2246,
              January 1999.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P. and elaborated]

   SIP basic T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

   [RFC2617]  Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S.,
              Leach, P., Luotonen, A. and digest authentication [6] MAY be used for
   SUBSCRIBE/NOTIFY messages used for enrollment L. Stewart, "HTTP
              Authentication: Basic and Digest Access Authentication",
              RFC 2617, June 1999.

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000.

   [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
              A., Peterson, J., Sparks, R., Handley, M. and configuration
   change notification.  There is a chicken E. Schooler,
              "SIP: Session Initiation Protocol", RFC 3261, June 2002.

   [RFC3263]  Rosenberg, J. and egg problem.  Since the

   Petrie         Informational - Expires Aug. 2003                17 
                         A Framework for H. Schulzrinne, "Session Initiation
              Protocol (SIP): Locating SIP                Feb. 2003
                       User Agent Configuration

   content of SUBSCRIBE/NOTIFY messages are transported in the clear,
   the credentials that the UA uses in the SUBSCRIBE 401 challenge, or
   that the configuration server uses in the NOTIFY 401 challenge must
   be provisioned out of band (i.e. user or administrator manual input,
   beamed via PDA, smart card, etc.) via a secure means. Servers", RFC 3263, June
              2002.

   [RFC3265]  Roach, A., "Session Initiation Protocol (SIP)-Specific
              Event Notification", RFC 3265, June 2002.

   [RFC3361]  Schulzrinne, H., "Dynamic Host Configuration data profile URLs are communicated in the clear in the
   NOTIFY requests from Protocol
              (DHCP-for-IPv4) Option for Session Initiation Protocol
              (SIP) Servers", RFC 3361, August 2002.

   [RFC3377]  Hodges, J. and R. Morgan, "Lightweight Directory Access
              Protocol (v3): Technical Specification", RFC 3377,
              September 2002.

   [RFC3617]  Lear, E., "Uniform Resource Identifier (URI) Scheme and
              Applicability Statement for the configuration server. Trivial File Transfer
              Protocol (TFTP)", RFC 3617, October 2003.

Author's Address

   Daniel Petrie
   Pingtel Corp.
   400 W. Cummings Park
   Suite 2200
   Woburn, MA  01801
   US

   Phone: "Dan Petrie (+1 781 970 0111)"<sip:dpetrie@pingtel.com>
   EMail: dpetrie@pingtel.com
   URI:   http://www.pingtel.com/

Appendix A. Acknowledgments

Intellectual Property Statement

   The security risk of
   unauthorized access of the URL content can be mitigated if IETF takes no position regarding the
   configuration server and UA both support basic authentication and
   HTTP validity or HTTPS.  There is a chicken and egg problem here as well
   since the content scope of SUBSCRIBE/NOTIFY messages are transported in
   the clear.  Accordingly,the credentials any
   intellectual property or other rights that the UA uses for the
   HTTP/HTTPS GET/POST 401 challenge must might be provisioned out of band
   (i.e. user or administrator manual input, beamed via PDA, smart
   card, etc.) via a secure means.

   Using HTTPS over TLS[13] the configuration server MAY request claimed to
   pertain to the
   certificate implementation or use of the UA [14].  If technology described in
   this level of authentication is
   desired, document or the UA vendor SHOULD ship extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights. Information on the UA
   IETF's procedures with a digital certificate
   or provide a means by which this respect to rights in standards-track and
   standards-related documentation can be installed out found in BCP-11. Copies of band.  The
   configuration server MUST be provisioned with the certificates
   claims of
   authority allowed rights made available for each model publication and any assurances of UA
   licenses to be supported.

   Using HTTPS the UA MAY request made available, or the certificate result of an attempt made to
   obtain a general license or permission for the configuration
   server.  If this level use of authentication is desired such
   proprietary rights by implementors or users of this specification can
   be obtained from the UA must 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
   provisioned with required to practice
   this standard. Please address the allowed certificate(s) of authority and
   identities for information to the configuration server out IETF Executive
   Director.

   The IETF has been notified of band (i.e. user or
   administrator manual input, beamed via PDA, smart card, etc.) via a
   secure means.

10 Open Issues

   [Do we need an option for the configuration server intellectual property rights claimed in
   regard to tell some or all of the UA
   that it MUST make specification contained in this
   document. For more information consult the change immediately regardless online list of state?
   Should this claimed
   rights.

Full Copyright Statement

   Copyright (C) The Internet Society (2003). All Rights Reserved.

   This document and translations of it may be the default?]

   [Upload copied and furnished to configuration server configuration data profiles
   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
   changes only ?? define in profiles ??]

   [Security considerations section needs much elaboration]

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                         A Framework for SIP                Feb. 2003
                       User Agent Configuration

11 References

      [1] R. Droms, "Dynamic host configuration protocol," Request for
      Comments (Draft Standard) 2131, Internet Engineering Task Force,
      Mar. 1997.

      [2] S. Alexander part, without restriction of any
   kind, provided that the above copyright notice and R. Droms, "DHCP options this paragraph are
   included on all such copies and BOOTP vendor
      extensions," Request for Comments (Draft Standard) 2132, Internet
      Engineering Task Force, Mar. 1997.

      [3] H.Schulzrinne , ˘Dynamic Host Configuration Protocol (DHCP-
      for-IPv4)÷, Request for Comments (Draft Standard) 3361, Internet
      Engineering Task Force, Aug. 2002.

      [4] S. Bradner, "Key words for use derivative works. However, this
   document itself may not be modified in RFCs any way, such as by removing
   the copyright notice or references to indicate
      requirement levels," Request for Comments (Best Current Practice)
      2119, Internet Engineering Task Force, Mar. 1997.

      [5] A. Gulbrandsen, P. Vixie, and L. Esibov, ˘A DNS RR for
      specifying the location of services (DNS SRV),÷ Request for
      Comments 2782, Internet Engineering Task Force, Feb. 2000.

      [6] Rosenberg, et. al., ˘SIP: session initiation protocol,÷
      Request for Comments 3261, Internet Engineering Task Force, June
      2002

      [7] A. Roach, ˘Event Notification in SIP÷, Request for Comments
      3265, Internet Engineering Task Force, June 2002

      [8] D. Crocker, ˘STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT
      MESSAGES÷, Request for Comments 822, Society or other
   Internet Engineering Task
      Force, Aug. 1982

      [9] K. Sollins, ˘THE TFTP PROTOCOL (REVISION 2)÷, Request organizations, except as needed for
      Comments 1350, the purpose of
   developing Internet Engineering Task Force, Jul. 1992

      [10] H Schulzrinne, ˘Configuring IP Telephony End Systems÷,
      <schulzrinne-sip-config-00.txt>, IETF; Dec. 2000,  Work standards in
      progress

      [11] D. Petrie, ˘Requirements which case the procedures for a SIP User Agent Configuration
      Framework÷, <draft-ietf-sip-config-framewk-reqs-00.txt>, IETF;
      Feb. 2003, Work
   copyrights defined in progress

      [12] T. Berners-Lee et al, ˘Uniform Resource Locators (URL)÷,
      Request for Comments 1738, Internet Engineering Task Force, Dec.
      1994

      [13] E. Rescorla, ˘HTTP Over TLS÷, Request for Comments 2818,
      Internet Engineering Task Force, May 2000

   Petrie         Informational - Expires Aug. 2003                19 
                         A Framework for SIP                Feb. 2003
                       User Agent Configuration

      [14] T. Dierks, C. Allen, ˘The TLS Protocol Version 1.0÷, Request
      for Comments 2246, the Internet Engineering Task Force, Jan. 1999

      [15] S. Olson ˘A Mechanism for Content Indirection in Session
      Initiation Protocol (SIP) Messages÷, <draft-ietf-sip-content-
      indirect-mech-01>, IETF; Nov. 2002, Work in progress

      [16] H. Sinnreich, ˘SIP Telephony Device Requirements,
      Configuration Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and Data÷, <draft-sinnreich-sipdev-req-00.txt>,
      IETF; Nov. 2002, Work in progress

      [10] H Schulzrinne, ˘Configuring IP Telephony End Systems÷,
      <schulzrinne-sip-config-00.txt>, IETF; Dec. 2000,  Work in
      progress

      [11] D. Petrie, ˘Requirements for a SIP User Agent Configuration
      Framework÷, <draft-petrie-sip-config-framewk-reqs-00.txt>, IETF;
      Feb. 2001, Work in progress

      [12] T. Berners-Lee et al, ˘Uniform Resource Locators (URL)÷,
      Request for Comments 1738, Internet Engineering Task Force, Dec.
      1994

      [13] E. Rescorla, ˘HTTP Over TLS÷, Request for Comments 2818, will not be
   revoked by the Internet Engineering Task Force, May 2000

      [14] T. Dierks, C. Allen, ˘The TLS Protocol Version 1.0÷, Request 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.

Acknowledgment

   Funding for Comments 2246, the RFC Editor function is currently provided by the
   Internet Engineering Task Force, Jan. 1999

      [15] S. Olson ˘A Mechanism for Content Indirection in Session
      Initiation Protocol (SIP) Messages÷, <draft-ietf-sip-content-
      indirect-mech-01>, IETF; Nov. 2002, Work in progress

12 Author's Address

   Dan Petrie
   Pingtel Corp.
   400 W. Cummings Park         Phone:  +1 781 938 5306
   Woburn, MA USA               Email:  dpetrie@pingtel.com

   Petrie         Informational - Expires Aug. 2003                20 Society.