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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
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Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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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
Satou, Ohta, Jacquenet, Hayashi, He [Page 18]
Internet Draft AAA and Admission Control Framework for
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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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Internet Draft AAA and Admission Control Framework for
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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
Satou, Ohta, Jacquenet, Hayashi, He [Page 22]
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