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   Internet Draft                             Hiroaki Satou, NTT
   Intended Status: Informational              Hiroshi Ohta, NTT
   Expires: August 1, 2009   Christian Jacquenet, France Telecom
                                          Tsunemasa Hayashi, NTT
                                    Haixiang He, Nortel Networks

                                                January 28, 2009

   AAA and Admission Control Framework for Multicasting
       <draft-ietf-mboned-multiaaa-framework-08.txt>


Status of this Memo
   This Internet-Draft is submitted to IETF in full conformance
   with the provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on August 1, 2009.

Copyright Notice

   Copyright (c) 2009 IETF Trust and the persons identified as the
   document authors. All rights reserved.


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Internet Draft  AAA and Admission Control Framework for
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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with
   respect to this document.

Abstract

   IP multicast-based services, such as TV broadcasting or
   videoconferencing raise the issue of making sure that
   potential customers are fully entitled to access the
   corresponding contents. There is indeed a need for service
   and content providers to identify users (if not
   authenticate, especially within the context of enforcing
   electronic payment schemes) and to retrieve statistical
   information for accounting purposes, as far as content and
   network usage are concerned. This memo describes the
   framework for specifying the Authorization, Authentication
   and Accounting (AAA) capabilities that could be activated
   within the context of the deployment and the operation of
   IP multicast-based services.  This framework addresses the
   requirements presented in "Requirements for Accounting,
   Authentication and Authorization in Well Managed IP
   Multicasting Services" [I-D.mboned-maccnt-req]. The memo
   provides a basic AAA enabled model as well as an extended
   fully enabled model with resource and admission control
   coordination.







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                Table of Contents
1. INTRODUCTION..................................................4
1.1 PURPOSE AND BACKGROUND.......................................4
2. DEFINITIONS AND ABBREVIATIONS.................................5
2.1 DEFINITIONS..................................................5
2.2 ABBREVIATIONS................................................6
3. COMMON USE MODELS AND NETWORK ARCHITECTURE IMPLICATIONS.......7
4. FRAMEWORK AND ROLES OF ENTITIES...............................9
4.1 "AAA FRAMEWORK IN MULTICAST-ENABLED ENVIRONMENTS.............9
4.1.1 MULTIPLE CPS ARE CONNECTED TO MULTIPLE NSPS................9
4.1.2 MULTIPLE CPS ARE CONNECTED TO A SINGLE NSP................11
4.1.3 A SINGLE CP IS CONNECTED TO MULTIPLE NSPS.................11
4.1.4 A SINGLE CP IS CONNECTED TO SINGLE NSP....................11
4.2 USER ID.....................................................12
4.2.1 CP-ASSIGNED USER ID.......................................12
4.2.2 NSP-ASSIGNED USER ID......................................12
4.3 ACCOUNTING..................................................13
4.4 ACCESS CONTROL AND CP SELECTION BY NSP......................14
4.5 ADMISSION CONTROL INFORMATION BY NSP........................14
4.6 ACCESS CONTROL AND DISTINGUISHING OF USERS BY CP............15
4.7 AAA PROXY IN NSP............................................15
5.1 BASIC CONNECTION MODEL......................................16
5.2 CONSTITUENT LOGICAL FUNCTIONAL COMPONENTS OF THE FULLY
ENABLED AAA FRAMEWORK...........................................17
5.3 MODULARITY OF THE FRAMEWORK.................................21
6. IANA CONSIDERATIONS..........................................21
7. SECURITY CONSIDERATIONS......................................21
8. CONCLUSION...................................................21


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1. Introduction

1.1 Purpose and Background

   IP multicasting is designed to serve cases of group
   communication schemes of any kind, such as one-to-many
   (case of TV broadcasting services for example) or many-to-
   many (case of videoconferencing services, for example).

   In these environments, IP multicast provides a better
   resource optimization than using a unicast transmission
   scheme, where data need to be replicated as many times as
   there are receivers. Activation of IP multicast
   capabilities in networks yields the establishment and the
   maintenance of multicast distribution trees that are
   receiver-initiated by nature: multicast-formatted data are
   forwarded to receivers who explicitly request them.
   IP multicast-based services, such as TV broadcasting or
   videoconferencing raise the issue of making sure that
   potential customers are fully entitled to access the
   corresponding contents. There is indeed a need for service
   and content providers to identify (if not authenticate,
   especially within the context of enforcing electronic
   payment schemes) and to invoice such customers in a
   reliable and efficient manner.  Solutions should consider a
   wide range of possible content delivery applications:
   content delivered over the multicast network may include
   video, audio, images, games, software and information such
   as financial data, etc.




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   This memo describes a framework for specifying the
   Authorization, Authentication and Accounting (AAA)
   capabilities that could be activated within the context of
   the deployment and the operation of IP multicast-based
   services. This memo also describes a framework to realize
   high-quality multicast transport using a Multicast
   Admission Control Function (MACF) with multicast
   Authorization.

   Specifically, this framework addresses the requirements
   presented in "Requirements for Multicast AAA coordinated
   between Content Provider(s) and Network Service
   Provider(s)" which describes the requirements in CDN
   services using IP multicast. The requirements are derived
   from:
        - need for user tracking and billing capabilities
        - need for network access control to satisfy the
   requirements of the Network Service Provider (NSP) and/or
   content access control to satisfy the requirements of the
   Content Provider (CP)
        - methods for sharing information between the network
   service provider and content provider to make it possible
   to fulfill the above two requirements. [I-D.mboned-maccnt-
   req]

   Detailed requirements are presented in "Requirements for
   Accounting, Authentication and Authorization in Well
   Managed IP Multicasting Services" [I-D.mboned-maccnt-req].
   These requirements include mechanisms for recording end-
   user requests and provider responses for content-delivery,
   sharing user information (possibly anonymously depending on
   the trust model) between content provider and network
   service provider, and protecting resources through the
   prevention of network and content access by unauthorized
   users, as well as other AAA related requirements.

   The purpose of this memo is to provide a generalized
   framework for specifying multicast-inferred AAA
   capabilities that can meet these requirements. This
   framework is to provide a basis for future work of
   investigating the applicability of existing AAA protocols
   to provide these AAA capabilities in IP multicast specific
   context and/or if deemed necessary, the refining or
   defining of protocols to provide these capabilities.


2. Definitions and Abbreviations

2.1 Definitions




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   For the purpose of this memo the following definitions
   apply:

   Accounting: The set of capabilities that allow the
   retrieval of a set of statistical data that can be defined
   on a per customer and/or a per service basis, within the
   context of the deployment of multicast-based services. Such
   data are retrieved for billing purposes, and can be
   retrieved on a regular basis or upon unsolicited requests.
   Such data include (but are not necessarily limited to) the
   volume of multicast-formatted data that have been forwarded
   to the receiver over a given period of time, the volume of
   multicast-formatted data that have been exchanged between a
   receiver (or set of) and a given source over a given period
   of time (e.g. the duration of a multicast session), etc.

   Authentication: action for identifying a user as a genuine
   one.

   Authorization: The set of capabilities that need to be
   activated to make sure an authenticated user is fully
   entitled to access a set of services.

   Join: Signaling mechanism used by receivers to indicate
   they want to access a multicast group and receive the
   corresponding traffic.

   Leave: Signaling mechanism used by receivers to indicate
   they want to leave a multicast group and not receive the
   corresponding traffic anymore.

   Receiver: an end-host or end-client which receives content.
   A receiver may be identified by a network ID such as MAC
   address or IP address.

   User: a human with a user account.  A user may possibly use
   multiple reception devices.  Multiple users may use the
   same reception device. (Note: The definition of a receiver
   (device) and a user (human) should not be confused.)


2.2 Abbreviations

   For the purpose of this draft the following abbreviations
   apply:

   AAA: Authentication.Authorization.and Accounting

   ACL: Access Control List




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   AN: Access Node

   CDN: Content Delivery Network

   CDS: Content Delivery Services

   CP: Content Provider

   CP-AAA: Authentication, Authorization, and Accounting
   functions used by a Content Provider

   CPE: Customer Premise Equipment

   ID: Identifier

   IF: network interface

   mAAA: Authentication, Authorization, and Accounting
   functions activated in multicast-enabled environments

   MACF: Multicast Admission Control Function

   NAS: Network Access Server (RFC2881)

   NSP: Network Service Provider

   NSP-mAAA: Authentication, Authorization, and Accounting
   functions used by a Network Service provider

   QoS: Quality of Service


3. Common use models and network architecture implications

   In some cases a single entity may design and be responsible
   for a system that covers the various common high-level
   requirements of a multicasting system such as 1) content
   serving, 2) the infrastructure to multicast it, 3) network
   and content access control mechanisms.

   In many cases however the content provision and network
   provision roles are divided between separate entities.
   Commonly, Content Providers (CP) do not build and maintain
   their own multicast network infrastructure as this is not
   their primary business area. CP often purchase transport
   and management services from network service providers
   instead. Similarly Network Service Providers (NSP) may not
   make their business in providing content. [I-D.mboned-
   maccnt-req] provides more detail of the multiple versus



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   single-entity Content Delivery Service (CDS) network
   models.

   In the usage model where a single NSP provides multicast
   services to multiple CPs, the following general
   requirements from [I-D.mboned-maccnt-req] apply:

        -Need for user tracking and billing capabilities
        -Need for QoS control such as resource management and
   admission control
        -Need for conditional multicast access control
   satisfactory to the requirements of the CP
        -Methods for sharing information between the NSP and
   CP to make the above two possible


   When the NSP and CP are the same single entity then the
   general requirements are as follows.

        -Need for user tracking and user-billing capabilities
        -Need for access control and/or content protection at
   level the entity deems appropriate





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4. Framework and Roles of Entities

4.1 AAA Framework in Multicast-Enabled Environments

   A general high-level framework is depicted in Figure 1.

            +------------------------------+
            |    user                      |
            |                              |
            +------------------------------+
                          |
                          |
                          |
            +------------------------------+
            |    NSP                       |
            |                              |
            +------------------------------+
                          |
                          |
                          |
            +------------------------------+
            |    CP                        |
            |                              |
            +------------------------------+

   Figure 1: High-level AAA framework in Multicast-Enabled
   Environments

   For the sake of simplicity, the above diagram portrays a
   case where there is a single NSP entity and a single CP
   entity (one-to-one model), but multiple CPs can be
   connected to a single NSP (e.g. NSP may provide connections
   to multiple CPs to provide a wide selection of content
   categories: one-to-many model) It is also possible for a
   single CP to be connected to multiple NSP networks (e.g.
   network selection). Furthermore it is possible that the NSP
   and CP could be the same entity. A NSP and CP authenticate
   and authorize each other when they establish connectivity.
   Below the general case of multiple NSPs with multiple CPs
   is explained.  Then, the various combinations of single and
   multiple CPs and NSPs are described in relation to the
   general case.

4.1.1 Multiple CPs are connected to multiple NSPs

   The user subscribes to multiple NSPs and multiple CPs in
   this usage case.  The user selects a CP and a NSP when the
   user requests content. The NSP may be automatically
   selected by a user terminal: e.g. a fixed line NSP by a set
   top box or a mobile NSP by a mobile phone.  In some usage



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   cases it is possible that the NSP used by a certain user
   will not always be the same.  For example a user may have
   contracted with more than one NSP: one for fixed line
   access and another for mobile roaming access.

   The content may be associated with (or managed by) a
   specific CP. In this case, when the user selects content,
   the CP is automatically selected.

   Requests for multicast sent by the user to a selected NSP
   should include enough information not only for
   authentication by the CP but also for CP selection and
   admission control by the NSP.

   When an NSP receives a request for multicast from a user,
   the NSP requests the appropriate CP to make sure that the
   user is entitled to access the corresponding content As
   the NSP is responsible for managing its network resources,
   the NSP may perform admission control.The NSP will allow
   access to the multicast service, depending on both the
   response sent by the CP and the availability of resources
   operated by the NSP.  That is, the NSP will forward
   multicast traffic towards the user only when the NSP has 1)
   made sure the user is entitled to access the network
   resources operated by the NSP, 2) received a confirmation
   from the CP that the user is entitled to access the content
   and (possibly) 3) determined that the network resources
   (e.g. bandwidth) are sufficient to deliver the multicast
   traffic to the user with the relevant level of quality.
   When neither of the first two conditions are met, the NSP
   will not forward multicast traffic to the user. Condition
   #3 may also be a showstopper. When the NSP already knows
   that network resources are insufficient or there is a
   network failure, the NSP may choose to not request the CP
   about the user's ability to retrieve content. The NSP is
   also responsible for notifiying the user whether he/she is
   eligible to receive content depending on the response sent
   by the CP. In cases where the NSP does not start
   multicasting because of its own network issues (e.g. lack
   of network resources or network failure), the NSP notifies
   the user with a reason for rejecting the request.

   A CP receives an inquiry from the NSP. The CP authenticates
   the NSP's identity and makes an authorization decision
   regarding the user's eligibility to access the requested
   contents.  The CP is responsible for the authentication
   and authorization of users so that they can access the
   content managed by the CP. The CP notifies the NSP
   accordingly. When the CP cannot (e.g. error or resource
   issues) or decides not (e.g. policy issues) to deliver



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   content, the CP is responsible for notifying the NSP about
   the reason.  It is up to the NSP to relay or translate the
   reasons for rejection to the user.

   A CP may delegate AAA responsibility to a NSP. 'AAA proxy
   in NSP' is described in 4.7 for this case.

   As defined in [I-D.mboned-maccnt-req], the CP may require
   the retrieval of accounting information related to the
   access of its content.

4.1.2 Multiple CPs are connected to a single NSP

   The user subscribes to a single NSP which provides
   multicasting from multiple CPs in this usage case. In this
   case the user does not select an NSP.  The user selects a
   CP when the user requests content. The content may be
   associated with (or managed by) the specific CP, so that
   when the user selects content, the CP is automatically
   selected.

   The user should send a request for multicast to the
   specific NSP with enough information not only for
   authentication by the CP but also for CP selection and
   admission control by the NSP.

   The role of the NSP is the same as that described in 4.1.1.

   The role of a CP is the same as that described in 4.1.1.

4.1.3 A single CP is connected to multiple NSPs

   In this usage case, a user subscribes to multiple NSPs but
   only a single CP.  A user selects the NSP when the user
   requests multicast but the CP is fixed.  The user should
   send a request for multicast to the selected NSP with
   enough information not only for authentication by the CP
   but also for admission control by the NSP.

   The role of the NSP is similar to the description in 4.1.1,
   with the exception that when a NSP receives a request from
   a user, NSP makes an inquiry to the CP without CP selection.

   The role of the CP is the same as that described in 4.1.1.

 4.1.4 A single CP is connected to single NSP

   In this case, a user subscribes to only one NSP and one CP.
   The user does not select a NSP and CP in this scenario.
   Requests for multicast sent by the user to a selected NSP



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   should include enough information not only for
   authentication by the CP but also for admission control by
   the NSP.

   The role for the NSP is the same as 4.1.3
   The role of the CP is the same as the description in 4.1.1.

   The NSP and CP could be the same entity. In this case, the
   roles of the NSP and CP may be combined.


4.2 User ID

   Users may hold multiple user IDs: IDs which have been
   separately assigned for each subscription to various NSPs
   and CPs.  The NSPs and CPs manage the user IDs for their
   respective domains. A CP identifies a user by a user ID
   assigned by the CP itself. A NSP identifies a user by a
   user ID assigned by the NSP itself. The user IDs are only
   meaningful within the context of each domain. Users may
   hold multiple user IDs which have been separately assigned
   for each subscription they may have for various NSPs and
   CPs.

4.2.1 CP-assigned user ID

   CPs assign user IDs to their users. The user may have more
   than one CP-assigned user ID per specific CP.  A user
   requests multicast to a NSP, the CP-assigned user ID should
   be indicated so that the CP can identify the user
   requesting content access.  A NSP should notify the CP-
   assigned user ID to the CP. A NSP should not share a CP-
   assigned user ID with any CP except the one which assigned
   it and should not relay it at all if there is no
   appropriate CP that assigned the user ID.

4.2.2 NSP-assigned user ID

   NSPs assign user IDs to their users. A user may have more
   than one NSP-assigned user ID per a specific NSP.  A user
   requests for multicast to a NSP, the NSP-assigned user ID
   may be indicated in the request so that the NSP can
   identify the user. The NSP should not inform the NSP-
   assigned user ID to the CP for security reasons. The NSP
   may identify the multicast-access user by other methods
   than the NSP-assigned userID, e.g. by the access port.




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   The actual mapping rules for NSP-assigned user IDs with CP-
   user assigned IDs in account logs is a matter for the
   providers and out of the scope of this framework.

4.3 Accounting

   There are some accounting issues specific to multicasting.
   An (S,G) should be recorded as a channel identifier. The
   last hop device, such as an IGMP or MLD router or an IGMP
   or MLD proxy, notifies the NSP's mAAA function of the (S,G)
   channel identifier.  The NSP should notify the CP of the
   (S,G) information in the accounting report messages.

   A NSP records an accounting start corresponding to only the
   first Join for a specific user-access session. A NSP should
   not treat a "Join" response to a Query as the accounting
   start.

   A NSP records an accounting stop triggered by any of the
   following: 1) a user requested Leave, 2) a timeout of a
   multicast state or 3) a re-authentication failure. A NSP
   may also record an accounting stop due to network
   availability reasons such as failure. The NSP logs the
   reason for each accounting stop.

   Intermittent logs between the join and leave would allow
   for finer diagnostics and therefore could serve useful in
   billing discrepancies, and provide for a better estimation
   of the time-span that content was multicast, in the event
   that users disconnect without sending leave messages.

   There are two levels of accounting report messaging.
   Messages in Accounting level 1 include a channel identifier,
   a user identifier, and the accounting start and stop time
   information. Accounting level 2 includes all information of
   Level 1, plus traffic volume information.

   QoS class is an optional item for each accounting level.
   Whether to send, and at what interval to send intermittent
   log information is optional for both levels. CP and NSPs
   may also agree to include additional option information in
   accounting messages of either level.

   The level of account report messaging between the NSP and
   CP may be either configured statically or can be
   dynamically requested by the CP in its response to the
   Access-Request relayed by the NSP to the CP.  The
   determination of the actual level of report messaging is
   configured by the NSP at the NAS.




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   In case of very fast channel changes, the amount of items
   logged by the NSP could become high.  In order to reduce
   the number of report messages sent to the CP, the NSP can
   consolidate multiple sets of accounting information inside
   a single accounting report message. [I-D.ancp-framework]


4.4 Access Control and CP selection by NSP

   When a NSP receives an access request from a user, the NSP
   determines to which CP the request is to be directed.  The
   NSP may select a CP based on CP-assigned userID with CP
   domain name or channel identifier (S,G). The user should
   include in the request sufficient information for CP
   selection.


4.5 Admission Control Information by NSP

   After authorizing a user request, the NSP may have further
   conditions for determining its admission control decision.

   The NSP receives parameters (such as QoS class, required
   bandwidth, burst-size, etc.) of multicast traffic.  Such
   parameters serve as information to be considered in the
   admission control decision. The traffic parameters can be
   communicated as follows:
        - A CP may notify a mapping between the channel
   identifier (S,G) and traffic parameters in the Response
   message when the CP authorizes an access request.  Such
   parameters may include required bandwidth, burst-size, QoS
   class downgrade policy, etc.
        - A user may indicate in the Request willingness to
   accept QoS class downgrade to best-effort streaming.
        - The NSP may maintain a mapping between channel
   identifier (S,G) and traffic parameters in advance, for
   example pre-configured by agreement between the CP and NSP
   on a per channel (S,G) basis.

   The ultimate admission decision is made by the NSP based on
   required traffic parameters of the requested, and available
   resources. In a case that it cannot guarantee the required
   network resources for the requested multicast traffic,
   streaming the requested multicast traffic as best-effort is
   optional.    The user may indicate in his/her Access
   Request whether he/she will accept best-effort grade
   streaming if guaranteed class is not available. The CP's
   preference for accepting downgrading to best-effort
   streaming may be either configured statically or can be
   dynamically requested by the CP in its response to the



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   Access-Request relayed by the NSP to the CP.  In the case
   that it cannot be offered a guaranteed QoS stream, the NSP
   may decide either to decline admission or to stream the
   requested multicast traffic as best-effort. The NSP should
   not stream best-effort traffic if either the user or CP has
   indicated against best-effort provision.

   A NSP's admission control may manage integrated network
   resources for unicast usage, such as VoIP or unicast
   streaming, and multicast usage. Alternatively, it may
   manage network resources separately for unicast and
   multicast usage. In either ease, AAA and admission control
   framework for multicast usage is independent of unicast
   admission control.

   Such QoS measurement and policy mechanisms themselves
   depend on NSP policies and are out of the scope of this
   memo.

4.6 Access Control and Distinguishing of Users by CP

   The user ID and authentication information are forwarded
   transparently by the NSP so that the CP can distinguish the
   user, as well as authenticate and authorize the request.

4.7 AAA proxy in NSP

   A NSP may act as AAA proxy of a CP based upon an agreement
   between the NSP and the CP.  The AAA proxy would store
   information about permissions of a specific user to receive
   multicast data from specified channel(s) up to specified
   expiration date(s) and time(s).

   If such proxying is implemented, the NSP may receive
   authorization conditions from a CP in advance and
   statically hold them, or a CP may send them dynamically in
   the Response message.  In either case, the user has
   permission to receive multicast traffic and therefore the
   NSP starts the multicasting without querying the CP.

   The CP may send unsolicited requests to the NSP to refresh
   or change the permissions for a user for specific group(s)
   or channel(s).

   When a user is receiving multicast traffic while the
   permission is about to expire, the NSP may send a
   notification to the user client that his session is about
   to expire, and that he will need to re-authenticate. In
   such a case, the user will have to send the Access-Request.
   In the case that the user still has permission to the



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   content, they should be able to continue to receive the
   multicast traffic without interruption.

   When re-authentication fails, the NSP should stop the
   multicast traffic and record accounting stop.

   5. Network Connection Model and Functional Components

   Section 3.1 introduced the high-level AAA framework for
   multicasting.  This section provides more detail on the
   network connection model and constituent functional
   components.

5.1 Basic Connection Model


            +------------------------------+
            |    receiver                  |
            |                              |
            +------------------------------+
                |        ^ Response
                | Request      |
                V              |
            +------------------------------+
            |    NSP's network                       |
            |                              |
            +------------------------------+
                |          ^ Response
                | Request        | (Success)
                v                |
            +------------------------------+
            |    CP's network                        |
            |                              |
            +------------------------------+

          Figure 2: Basic Connection Model

   In the simple case represented in Figure 1 the NSP is the
   sole entity providing network resources including network
   access to the multicast receiver.  First a receiver sends a
   request for multicast (e.g. an IGMP Report message) to an
   NSP which may then forward a mAAA request towards the
   appropriate CP for authentication and authorization
   purposes. The receiver gets information about a given
   multicast group (*,G) or channel (S,G) corresponding to the
   content beforehand for generating the request. The CP
   responds with either "success" or "failure".  If "success",
   the NSP grants access to the receiver and forwards
   multicast traffic accordingly.




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   In this model the receiver selects the NSP to which the
   Join request will be sent.  Based on this request the NSP
   selects an appropriate CP to which it forwards the
   corresponding mAAA request. The CP responds to the NSP's m
   AAA request:  it may not respond to another NSP in regards
   to the request.

   In this model, as described in section 4.1, the
   relationship between NSP and CP can be one-to-one, one-to-
   many or many-to-many.  Receivers may connect to multiple
   networks.

5.2 Constituent Logical Functional Components of the fully
enabled AAA Framework

   Requirements for "fully AAA and QoS enabled" IP
   multicasting networks were defined in MACCNT-REQ-draft. To
   allow for levels of enablement, this memo defines two
   models within the framework: "AAA enabled" multicasting and
   "Fully enabled AAA" multicasting which means "AAA enabled"
   with added admission control functions.

   Section 3.1 introduces the high-level AAA framework for
   multicasting.  Below is a diagram of a AAA enabled
   multicasting network with AAA, including the logical
   components within the various entities.



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            +-------------------------------+
            | user                          |
            |+- - - - - - - - - - - - - - -+|
            || CPE                         ||
            ||                             ||
            |+- - - - - | - - - - - - - - -+|
            +-----------|-------------------+
                        |
                 -------|------ IFa
                        |
            +-----------|-------------------+
            | NSP       |                   |
            |+- - - - - |- -_+              |
            ||TS        |    |              |
            |    +------|-+                 |
            ||   | AN     |  |              |
            |    |        |---------+       |
            ||   +------|-+  |      |       |
            |           |     IFb   |       |
            ||   +------|-+  | | +---------+|
            |    |        |----|-|mAAA     ||
            ||   | NAS    |  | | |(MACF *) || * optional
            |    +--------+      +---------+|
            ||+- - - - - - - +      |       |
            +-----------------------|--------+
                                    |
                             -------|------ IFc
                                    |
            +-----------------------|-------+
            | CP               +---------+  |
            |                  |  CP-AAA |  |
            |                  +---------+  |
            +-------------------------------+
      Figure 3: AAA enabled framework (basic model)



   The user entity includes the CPE (Customer Premise
   Equipment) which connects the receiver (s).

   The NSP (Network Service Provider) in the basic model
   includes the transport system and a logical element for
   multicast AAA functionality.  The TS (transport system) is
   comprised of the access node and NAS (Network Access
   Server) An AN (Access Node) may be connected directly to
   mAAA or a NAS relays AAA information between an AN and a
   mAAA. Descriptions of AN and its interfaces are out of the
   scope for this memo.  The multicast AAA function may be
   provided by a mAAA which may include the function that



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   downloads Join access control lists to the NAS (this
   function is referred to conditional access policy control
   function.)


   Interface between mAAA and NAS

   The interface between mAAA and the NAS is labeled IFb in
   Figure 2. Over IFb the NAS sends an access request to the
   NSP-mAAA and the mAAA replies. The mAAA may push
   conditional access policy to the NAS.

   CP-AAA
   The content provider may have its own AAA server which has
   the authority over access policy for its contents.

   Interface between user and NSP
   The interface between the user and the NSP is labeled IFa
   in Figure 3.  Over IFa the user makes a multicasting
   request to the NSP.  The NSP may in return forward
   multicast traffic depending on the NSP and CP's policy
   decisions.

   Interface between NSP and CP
   The interface between the NSP and CP is labeled IFc. Over
   IFc the NSP requests to the CP-AAA for access to contents
   and the CP replies.  CP may also send conditional access
   policy over this interface for AAA-proxying.




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            +-------------------------------+
            | user                          |
            |+- - - - - - - - - - - - - - -+|
            || CPE                         ||
            ||                             ||
            |+- - - - - | - - - - - - - - -+|
            +-----------|-------------------+
                        |
                 -------|------ IFa
                        |
            +-----------|-----------------------+
            |+- - - - - |- - _+   + - - - - - + |
            ||        |   | |   |           | |
            |    +------|-+ |       +--------+  |
            ||   | AN     | | |   | | MACF  || |
            |    |        | |       |        |  |
            ||   +------|-+ | |   | +---|----+| |
            |           |   |           |    |  |
            |           |   | |     IFd----- |  |
            |           |   |  IFb      |    |  |
            ||   +------|---+ | | | +---|----+| |
            |    |          |---|---| mAAA   |  |
            ||   | NAS      | | | | |(MACF *)|| | * optional
            |    +----------+ |     +--------+  |
            ||+- - - - - - - -+ - - |- - - - -+ |
            +-----------------------|-----------+
                                    |
                             -------|------ IFc
                                    |
            +-----------------------|-------+
            | CP               +---------+  |
            |                  |  CP-AAA |  |
            |                  +---------+  |
            +-------------------------------+

             Figure 4: Fully enabled framework

   In the fully enabled model the NSP also includes a
   component that provides network resource management (e.g.
   QoS management), as described in section 3.4, "Network
   Resource Management by NSP".  In the fully enabled model
   (Figure 3) resource management and admission control is
   provided by MACF (Multicast Admission Control Function).
   This means that, before replying to the user's multicast
   request, the mAAA queries the MACF for a network resource
   access decision over the interface IFd. The MACF is
   responsible for allocating network resources for forwarding
   multicast traffic.  MACF also receives Leave information
   from NAS so that MACF releases corresponding reserved
   resources.



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5.3 Modularity of the framework

   In the interest of flexibility, this framework is modular
   so that it is possible that partially enabled versions of
   the models are supported.  A AAA-enabled version provides
   AAA functionality without Network Resource management.  A
   Network-Resource-Management-enabled (QoS-enabled) version
   provides Network Resource management without AAA
   functionality.  Similarly, the possibility of one or more
   layers of transit provision between an NSP and CP is in the
   interest of modularity and extendibility.


6. IANA considerations

   This memo does not raise any IANA consideration issues.


7. Security considerations

   The user information related to authentication with the CP
   and the information related to user accounting shared
   between the NSP and the CP must be protected in some way.
   Otherwise, this memo does not raise any new security issues
   which are not already addressed by the original protocols.
   Enhancement of multicast access control capabilities should
   enhance security performance.


8. Conclusion

   This memo provides a generalized framework for solution
   standards to meet the requirements.  Further work should be
   done to specify the interfaces between the user and NSP,
   NAS and mAAA, mAAA and MACF and NSP-mAAA and CP-AAA
   (presented in 5.2.)


Normative References

   [I-D.mboned-maccnt-req]
      Hayashi, et. al., "Requirements for Multicast AAA
      coordinated between Content Provider(s) and Network
      Service Provider(s)", draft-ietf-mboned-maccnt-req-
      07.txt, January 2009, Work in Progress.

   [I-D.ancp-framework]
      Ooghe, et. al, "Framework and Requirements for an
      Access Node Control Mechanism in Broadband Multi-



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      Service Networks", draft-ietf-ancp-framework-07.txt,
      November 2008, Work in Progress.


Authors' Addresses

           Hiroaki Satou
           NTT Network Service Systems Laboratories
           3-9-11 Midoricho, Musashino-shi, Tokyo, 180-8585
           Japan
           Phone : +81 422 59 4683
           Email : satou.hiroaki@lab.ntt.co.jp

           Hiroshi Ohta
           NTT Network Service Systems Laboratories
           3-9-11 Midoricho, Musashino-shi, Tokyo, 180-8585
           Japan
                   Phone : +81 422 59 3617
           Email: ohta.hiroshi@lab.ntt.co.jp

           Christian Jacquenet
           France Telecom
           3, avenue Francois Chateau
           CS 36901, 35069 Rennes Cedex, France
           Phone: +33 2 99 87 61 92
           Email: christian.jacquenet@orange-ftgroup.com

           Tsunemasa Hayashi
           NTT Network Innovation Laboratories
           1-1 Hikari-no-oka, Yokosuka-shi, Kanagawa, 239-0847
           Japan
           Phone: +81 46 859 8790
           Email: tsunemasa@gmail.com

           Haixiang He
           Nortel
           600 Technology Park Drive
           Billerica, MA 01801, USA
           Phone: +1 978 288 7482
           Email: haixiang@nortel.com









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