Internet Draft AAA Framework for Multicasting November
2007
Hiroaki Satou, NTT
Internet Draft Hiroshi Ohta, NTT
Expires: Jan 10, 2008 May 17, Christian Jacquenet, France Telecom
Intended status: Informational
2008
Tsunemasa Hayashi, NTT
Haixiang He, Nortel Networks
July 9,
November 19, 2007
AAA Framework for Multicasting
<draft-ietf-mboned-multiaaa-framework-04.txt>
<draft-ietf-mboned-multiaaa-framework-05.txt>
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Internet Draft AAA Framework for Multicasting November
2007
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This Internet-Draft will expire on January 10, May 17, 2008.
Copyright Notice
Copyright (C) The IETF Trust (2007). This document
is subject to the rights, licenses and restrictions
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the authors retain all their rights.
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
(if not authenticate, especially within the context
of enforcing electronic payment schemes) and to
invoice such customers in a reliable and efficient
manner. 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 draft-ietf-mboned-
maccnt-req-04.txt,
draft-ietf-mboned-maccnt-req-04.txt, "Requirements
for Accounting, Authentication and Authorization in
Well Managed IP Multicasting Services". The memo
provides a basic AAA enabled model as well as an
extended fully enabled model with resource and
admission control coordination.
STATUS OF THIS MEMO 1
COPYRIGHT NOTICE 2
ABSTRACT 2
1. INTRODUCTION 5
1.1 PURPOSE AND BACKGROUND 5
2. DEFINITIONS AND ABBREVIATIONS 6
2.1 DEFINITIONS 6
2.2 ABBREVIATIONS 7
3. COMMON USE MODELS AND NETWORK ARCHITECTURE IMPLICATIONS 7
4. FRAMEWORK AND ROLES OF ENTITIES 8
4.1 FRAMEWORK FOR MULTICAST AAA 8
4.1.1 MULTIPLE CPS ARE CONNECTED TO MULTIPLE NSPS 9
4.1.2 MULTIPLE CPS ARE CONNECTED TO A SINGLE NSP 10
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 11
4.2.1 CP-ASSIGNED USER ID 12
4.2.2 NSP-ASSIGNED USER ID 12
4.3 ACCOUNTING 12
4.4 ACCESS CONTROL AND CP SELECTION BY NSP 13
4.5 ADMISSION CONTROL INFORMATION BY NSP 13
4.6 ACCESS CONTROL AND DISTINGUISHING OF USERS BY CP 14
4.7 AAA PROXY IN NSP 14
5.1 BASIC CONNECTION MODEL 14
5.2 CONSTITUENT LOGICAL FUNCTIONAL COMPONENTS OF THE FULLY
ENABLED AAA FRAMEWORK 15
5.3 MODULARITY OF THE FRAMEWORK 19
6. IANA CONSIDERATIONS 19
7. SECURITY CONSIDERATIONS 19
8. CONCLUSION 19
NORMATIVE REFERENCES 19
AUTHORS' ADDRESSES 20
COMMENTS 20
FULL COPYRIGHT STATEMENT 21
COPYRIGHT (C) THE IETF TRUST (2007). 21
INTELLECTUAL PROPERTY 21
EXPIRATION 21
ACKNOWLEDGEMENT 22
1. Introduction
1.1 Purpose and Background
IP multicasting is designed to serve cases of group
communication schemes of any kind, such as 1-to-n (case of
TV broadcasting services for example) or n-to-p (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.
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 Resource and
Admission Control System (RACS) with multicast
Authorization.
Specifically, this framework addresses the requirements
presented in draft-ietf-mboned-maccnt-req-04.txt, draft-ietf-mboned-maccnt-req-05.txt,
"Requirements for Accounting, Authentication Multicast AAA coordinated between Content
Provider(s) and
Authorization in Well Managed IP Multicasting Services"
MACCNT-REQ-draft Network Service Provider(s)" MACCNT-REQ-
draft describes the requirements in CDN services using IP
multicast[1]. 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.
Detailed requirements are presented in MACCNT-REQ-draft.
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
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 a given requesting customer is (1)
what he claims to be (identification purposes), and (2) is
fully entitled to access a set of services (authentication
purposes).
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:
ACL: Access Control List
AN: Access Node
CAPCF: Conditional Access Policy Control Function
CDN: Content Delivery Network
CDS: Content Delivery Services
CP: Content Provider
CPE: Customer Premise Equipment
mRACF:
MACF: Multicast Resource and Admission Control Function
NSP: Network Service Provider
TS: Transport System
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. The MACCNT-REQ-
draft provides more detail of the multiple versus single
entity CDS network models.
As such it should not be assumed that the entity
responsible for the multicasting structure and the entity
responsible for content serving are the same. Indeed
because the infrastructure for multicasting is expensive
and many content holders are not likely to be competent at
building and maintaining complicated infrastructures
necessary for multicasting, many content holders would
prefer to purchase transport and management services from a
network service provider and thus share the infrastructure
costs with other content holders.
Similarly network service providers in many cases do not
specialize in providing content and are unlikely to build
and maintain such a resource-intensive system without a
certain level of demand from content holders.
The use model of a single NSP providing multicasting
services to multiple CPs the following general requirements
from MACCNT-REQ-draft apply:
-Need for user tracking and billing capabilities
-Need for QoS control such as resource management and
admission control
-Need for conditional content 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 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
4. Framework and Roles of Entities
4.1 Entities4.1 Framework for multicast
AAA
A general high-level framework can be represented as
follows.
+------------------------------+
| user |
| |
+------------------------------+
| Access ^ Response
| Request | & Multicast Data
V |
+------------------------------+
| NSP |
| |
+------------------------------+
| Access ^ Response
| Request | (Success)
v |
+------------------------------+
| CP |
| |
+------------------------------+
Figure 1
For the sake of simplicity, the above diagram portrays a
case where there is a single NSP entity and a single CP
entity, but multiple CPs can be connected to the same NSP. a single NSP
(e.g. NSP may provide connections to multiple CPs to
provide a wide selection of content categories.) It is also
possible for the same a single CP to be connected to multiple NSP
networks (e.g. network selection). In other
words the relationship of NSP:CP can be described as 1:1,
1:N or M:N. Furthermore it is
possible that the NSP and CP could be the same entity.
Description 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 Roles: 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 (or the user's device) 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 for STB by a set
top box or a mobile NSP for by a mobile phone. In some usage
cases it is possible that the NSP used by the a certain user terminal
will not always be the same. For example a user may have
contracted with different NSPs more than one NSP: one for fixed line or
access and another for mobile roaming access.
The CP is responsible for Authentication and Authorization
of users' access to content that may be associated with (or managed by) a
specific CP. In this case, when the user selects content,
the CP manages. is automatically selected.
The CP
hopes user should send an Access-Request to collect accounting information related to the
access of their content. The CP may choose to authenticate
and authorize NSPs which are eligible to provide users
access to its contents. When the CP cannot (e.g. error or
resource issues) or decides selected NSP
with enough information not (e.g. policy issues) to
deliver content, only for authentication by the
CP is responsible but also for notifying CP selection and admission control by the
NSP.
When an NSP receives an Access-Request from a user, the NSP of
selects the reason. It is up to appropriate CP for the NSP how to relay or
translate received Access-Request
and relays the messages to content request. As the user.
The NSP is responsible
for managing its network resources.
The resources, the NSP may perform
admission control. It is also
responsible for relaying the AAA messages from the CP
whether the user is eligible to receive content
(authentication by proxy), and the NSP's relevant AAA
server control.The NSP will allow access to the network
and contents conditional to both the CP AAA server's CP's content
authorization result and the NSPs network utilization
authorization result. In certain cases availability.
That is, the NSP starts multicast flow only when it has
both 1) received an accept response from the CP and NSP may
have a contractual relationship in which 2)
determined that the NSP is
authorized network resources (e.g. bandwidth) are
sufficient to make the content authorization decision based
on mutually predetermined criteria: in such cases the NSP-
AAA may also make the content authorization decision
without querying serve the CP-AAA. multicast channel. When neither of
these conditions are met, the NSP cannot or
decides does not to start the
requested multicast to users, channel. When the NSP may notify the
users of the reason. It is recommended already knows
that the NSP notify
eligible users of the reason for not multicasting content
when it is due network resources are insufficient or content unavailability, for
example. The there is a
network failure, the NSP may choose to not relay the
Access-Request to notify ineligible users
of the reason CP. The NSP is also responsible for any case.
4.2 Multiple User IDs
Users may hold multiple user IDs: IDs which have been
separately assigned for each subscription they may have for
various NSPs and CPs. The NSPs and CPs control
relaying the user
IDs for their respective domains. The user IDs are only
meaningful in Response message from the context of each domain.
When CP to the user wants to access content,
whether the user registers is eligible to receive content (in
response to the corresponding Access-Request from the user ID (including
to the CP.) In cases that the NSP does not start multicast
because of its CP domain
information) own network issues (e.g. lack of network
resources or network failure), the NSP notifies the user
with a request reason for content, etc: web
authentication is one possible method.
Each rejecting the request.
A CP may identify users receives an Access-Request relayed by the user IDs that it has
issued to them.
Terminal portability can be realized if the NSP NSP. The CP
authenticates a user using a NSP-assigned user ID. A NSP-
assigned user ID is the NSPs identity and makes an access-line independent unique ID
assigned authorization
decision regarding the NSPs eligibility to provide users which allows user identification from any
access point within the network to its contents. The CP is responsible for
Authentication and possibly roaming Authorization of users' access to
other networks. This allows
content that the user CP manages. The CP hopes to collect
accounting information related to access the content
from various network access points. of their
content. The CP responds to the NSP and regarding the relayed
Access-Request. When the CP do cannot (e.g. error or
resource issues) or decides not need (e.g. policy issues) to know
deliver content, the corresponding user
id CP is responsible for notifying the same user in
NSP of the other provider's domain, and it
is not necessary that there is a one to one relationship. reason. It is quite possible for one person up to hold multiple user
ids the NSP how to relay or
translate the reasons for rejection to the same provider.
The actual mapping rules for NSPs and user.
4.1.2 Multiple CPs are connected to map a single NSP
The user IDs
with the IDs in other provider domains is subscribes to a matter for single NSP which provides
multicasting of channels from multiple CPs in this usage
case. In this case the
providers. A solution should provide user does not select an API between the
providers to flexibly support various mapping methods.
4.3 Accounting
MACCNT-REQ-draft defines requirements for Accounting and
Billing. These include the requirement for the NSP to log NSP. The
user behavior such as selects a CP when the join action and user requests content. The
content may be associated with (or managed by) the leave action,
as well as specific
CP, when the result of user selects content, the access-control decision.
(MACCNT-REQ-draft, 4.5) MACCNT-REQ-draft also specifies
that there CP is automatically
selected.
The user should be a standardized way send an Access-Request to sharing the specific NSP
with enough information not only for authentication by the
CP the user behavior but also for CP selection and content reception information
which admission control by the
NSP.
The role of the NSP is logging.(MACCNT-REQ-draft, 4.5.1)
Standardization the same as that described in 4.1.1.
The role of a CP is the logs or messages to share content
usage information same as that described in 4.1.1.
4.1.3 A single CP is important connected to support a single NSP
sharing accounting information with multiple CPs or NSPs
A user subscribes to multiple NSPs but a single CP receiving from multiple NSPs.
In order to provide the granularity of user-behavior and
actual content reception information as specified in
MACCNT-REQ-draft, this
usage case. A user selects the NSP should not manage multicast
states on a subnet basis, when the user requests
content but on a the CP is fixed. The user basis (see in
MACCNT-REQ-draft, 4.1 "User identification") because should send an
Access-Request to the selected NSP needs to be able to notify with enough information
not only for authentication by the CP of a user's start and
stop times but also for accounting purposes. This means that
admission control by the NSP.
The role of the NSP
sends is similar to the CP AAA description in 4.1.1,
with the exception that when a NSP receives an indication for Join and Leave on Access-
Request from a
user basis. User-based multicast state management is
equivalent user, NSP relays it to explicit membership tracking the CP without CP
selection.
The role of the CP is the same as that described in RFC3376 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
per-host tracking one
CP. The user does not select NSP and CP in RFC3810.
This framework specifies this scenario.
The user should send an accounting API provided by Access-Request to the NSP and accessed with
enough information not only for authentication by the CP to allow
but also for sharing user-
behavior 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 content-reception information between CP could be the same entity. In this case, the
roles of the NSP
AAA and CP AAA. This accounting API should may be configurable
to allow combined.
4.2 User ID
Users may hold multiple user IDs: IDs which have been
separately assigned for each subscription they may have for
various NSPs and CPs. The NSPs and CPs manage the user IDs
for their respective domains. A CP to request identifies a user by a
user ID assigned by CP itself. A NSP identifies a user by a
user ID assigned by NSP itself. The user IDs are only
meaningful in the logging information it
actually requires. Such an API would allow context of each domain. Users may hold
multiple user IDs which have been separately assigned for realtime
accounting information sharing by
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 a specific CP. A user
sends an Access-Request 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 relay the CP-
assigned user ID from the user to the CP. When
logging information is shared through A NSP should not
send a CP-assigned user ID to any CP except the accounting API, one which
assigned it and should not relay it all if there is important no
appropriate CP that assigned the CP 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
sends an Access-Request to a NSP, the NSP-assigned user ID
may be able indicated in it so that the NSP can identify the
user. The NSP should not relay the NSP-assigned user ID to match
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.
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 specific accounting issues for multicasting.
A (S,G) should be recorded as
described a channel identifier. The
last hop devices, such as a IGMP or MLD router and a IGMP
or MLD proxy, notify a (S,G) to AAA function in the database operated by NSP.
The (S,G) information should be notified to the CP as part
of the accounting log.
A NSP records accounting start corresponding to only the
first Join for a specific user access session. A NSP should
not treat a Query-responded Join as described in the database operated by the CP.
The accounting start.
A NSP requires the capability to log both records accounting stop triggered by not only user and host
information for each join and leave, indicating the
corresponding multicast source for each action. When either
requested Leave but also timeout of a CP source stops sending, multicast state or the
re-authentication failure. A NSP stops multicasting,
in an unsolicited manner, there is may also a need record an
accounting stop due to notify
the AAA servers accordingly about network availability reasons such as
failure. The NSP logs the users who are
impacted by this event. reason for each accounting stop.
Also, 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 finer
estimation of the time span that spent for delivering the content was multicasted in
the even event that users disconnect without sending leave
messages.
4.4 Access Control and CP selection by NSP
When a NSP receives an access request from a user, it is
necessary for the NSP to determine
determines to which CP the request is to be directed. It is necessary for the The
NSP to ensure
that it is not spoofed by an inappropriate may select a CP based on CP-assigned userID with CP
domain name or user.
4.5 API 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.
MACCNT-REQ-draft defines requirements decision.
The NSP needs to know traffic parameters of a multicast
channel for admission control. The traffic parameter
information may be either indicated by the user or CP
within the access request and responses, or otherwise
shared between the NSP and CP outside the access-request
message mechanism:
- A user may declare traffic parameters for each
Access-Request.
- 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.
- 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 basis.
A NSPs 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 case, AAA and admission control
framework for providing the
network capability to conduct admission control based on
the network bandwidth multicast usage status and bandwidth management
policy. (MACCNT-REQ-draft, 4.2.2, 4.2.3 & 4.9) 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. However the NSP's AAA Server should be
provided with an Admission control API that allows for
interfacing so that additional conditions can be added to
the admission control decision.
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 Caching of AAA results
An proxy in NSP should be able to cache
A NSP may act as AAA results proxy of a CP based upon an agreement
between the NSP and a the CP. The AAA cache 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 caching proxying is implemented, a method must exist for the
CP to communicate this permission information to the NSP.
The NSP refers to the AAA cache may receive
authorization conditions from a CP in advance and if the cache indicates
that
statically hold them, or a CP may send them dynamically in
the Response message. The user has permission to receive
multicast data from
a specific channel at that time, the time. The NSP may forward starts the
data
multicasting without querying the CP.
It should be possible for a
The CP to may send unsolicited requests to the NSP to refresh
or change the permissions for a user for specific
channel(s).
When a user is receiving multicast content and 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-connect. The reauthenticate. In such
a case, the user will have to reestablish a connection. send the Access-Request. In
the case that the user still has permission to the content,
they should be able to continue to receive the content
without interruption.
When re-authentication fails, the NSP should stop the
multicast channel and record accounting stop.
5. Network Connection Model and Functional Components
Section 3.1 introduces the high-level AAA framework for
multicasting. This section provides more detail details on the
network connection model and constituent functional
components.
5.1 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 User. First a user that requests content
sends an Access request to an NSP which then forwards it on
to the appropriate CP for Authentication and Authorization
purposes. The CP responds with either "success" or
"failure". If "success", the NSP may forward a success
response and stream multicast data to the user.
In this model the user selects the NSP to which to send its
content request. Based on this request the NSP selects an
appropriate CP to which it forwards the request. The CP
responds to the NSP's request: it may not respond to
another NSP in regards to the request.
In this model, as described in section 3.1, the
relationship between NSP and CP can be 1:1, 1:N or M:N.
Users may connect to multiple networks, and networks have
multiple users.
5.2 Constituent Logical Functional Components of the fully
enabled AAA Framework
MACCNT-REQ-draft defined requirements
Requirements for "well managed" "fully AAA and QoS enabled" IP
multicasting which networks were defined in MACCNT-REQ-draft. To
allow for levels of enablement, this memo calls defines two
models within the framework: "AAA enabled"
multicasting. multicasting and
"Fully enabled AAA" multicasting in this memo which means "AAA enabled"
with added QoS 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.
AAA enabled framework (basic model)
+-------------------------------+
| user |
|+- - - - - - - - - - - - - - -+|
|| CPE ||
|| ||
|+- - - - - | - - - - - - - - -+|
+-----------|-------------------+
|
-------|------ IFa
|
+-----------|-------------------+
| NSP | |
|+- - - - - |- -_+ |
||TS | | |
| +------|-+ |
|| | AN | | |
| | | |
|| +------|-+ | |
| | IFb |
|| +------|-+ | | +---------+|
| | |----|-|mAAA ||
|| | NAS | | | | (CAPCF*)|| |(MACF *) || * optional
| +--------+ +---------+|
||+- - - - - - - + | |
+-----------------------|--------+
|
-------|------ IFc
|
+-----------------------|-------+
| CP +---------+ |
| | CP-AAA | |
| +---------+ |
+-------------------------------+
Figure 2
The user entity includes the CPE (Customer Premise
Equipment) which includes the user host(s) and optionally a
multicast proxy (not shown in the Figure 2.)
The NSP (Network Service Provider) in the basic model
includes the transport system and a logical element for
multicast AAA functionality. The transport system is
comprised of the access node and NAS (network access
server.)
server) An AN 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 scope for
this memo. The multicast AAA function may be provided by a
multicast AAA server (mAAA) which may include
a the function
by which the access policy is downloaded to the NAS (conditional
(Multicast access policy control function.) The interface between
mAAA and the NAS is labeled IFb in Figure 2. Over IFb the
NAS makes an access request to the NSP-mAAA and the mAAA
replies. The mAAA may push conditional access policy to the
NAS.
The content provider may have its own AAA server which has
the authority over access policy for its contents.
The interface between the user and the NSP is labeled IFa
in Figure 2. Over IFa the user makes a multicasting
request to the NSP. The NSP may in reply send multicast
traffic depending on the NSP and CP's CPs policy decisions.
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-caching. within the context of proxying
multicast AAA messagescaching.
Fully enabled framework (c)
+-------------------------------+
| user |
|+- - - - - - - - - - - - - - -+|
|| CPE ||
|| ||
|+- - - - - | - - - - - - - - -+|
+-----------|-------------------+
|
-------|------ IFa
|
+-----------|-----------------------+
|+- - - - - |- - _+ + - - - - - + |
||TS | | | | | |
| +------|-+ | +--------+ |
|| | AN | | | | | mRACF MACF || |
| | | | | | |
|| +------|-+ | | | +---|----+| |
| | | | | |
| | | | IFd----- | |
| | | IFb | | |
|| +------|---+ | | | +---|----+| |
| | |---|---| mAAA | |
|| | NAS | | | | |(CAPCF*)|| |(MACF *)|| | * optional
| +----------+ | +--------+ |
||+- - - - - - - -+ - - |- - - - -+ |
+-----------------------|-----------+
|
-------|------ IFc
|
+-----------------------|-------+
| CP +---------+ |
| | CP-AAA | |
| +---------+ |
+-------------------------------+
Figure 3
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 mRACF MACF (multicast resource and admission control
function.) This means that mRACF and Authorization portion
of mAAA comprise RACS. function).
Before replying to the user's multicast request the mAAA
queries the mRACF MACF for a network resource access decision
over the interface IFd. The mRACF MACF is responsible for
allocating network resources for multicast traffic. So that mRACF has To
provide MACF with the necessary relevant network resource
availability information, NAS notifies mRACF MACF via mAAA of the
stopping of that
sending multicast traffic. traffic has ceased.
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 An 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
Refer to section 3.3. Also the user information related to
authentication with 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 presented in MACCNT-REQ-
draft. requirements. Further work should be
done to specify the interfaces between the user and NSP,
NAS and mAAA, mAAA and
mRACF MACF and NSP-mAAA and CP-AAA
(presented in 5.2.)
Normative References
[1] Hayashi, et. al., "Accounting, Authentication Requirements for Multicast AAA
coordinated between Content Provider(s) and
Authorization Issues in Well Managed IP Multicasting
Services", draft-ietf-mboned-maccnt-req-04.txt,
February 2006, Network
Service Provider(s)", draft-ietf-mboned-maccnt-req-
05.txt, September 2007, Work in Progress.
[2] RFC-3810, Vida, R. and L. Costa, "Multicast Listener
Discovery Version 2 (MLDv2) for IPv6", June 2004.
[3] RFC-3376, Cain B., et.al., "Internet Group Management
Protocol, Version 3", October 2002.
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, R&D
4, rue du Clos Courtel -
- BP 91226
35512 Cesson-SvignECedex, France
Phone: +33 2 99 87 63 31 12 49 40
Email: christian.jacquenet@francetelecom.com 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
Comments
Comments are solicited and should be addressed to the
mboned working group's mailing list at
mboned@lists.uoregon.edu_and/or the authors.
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