Tsunemasa Hayashi, NTT
Internet Draft Haixiang He, Nortel Networks
Expires: October 21, 2006 Hiroaki Satou, NTT
Hiroshi Ohta, NTT
Susheela Vaidya, Cisco Systems
April 19, 2006
Issues Related to Receiver Access Control in the Current Multicast
Protocols
<draft-ietf-mboned-rac-issues-03.txt>
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Copyright Notice
Copyright (C) The Internet Society (2006)
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Abstract
This memo evaluates the extent to which current multicasting
protocols can be used to address common requirements for commercial,
large-scale IP multicasting, but may be applicable to non-commercial
deployments as well. Four existing possible multicasting
architectures (with or without some form of access or content
control) are presented. Then each architecture is analyzed with
respect to how it can or cannot satisfactorily address each issue.
This memo concludes that for many of these issues the possible
architectures based on present standards as they now exist require
non-standardized solutions to meet common use requirements. This
memo recommends for requirements to be defined that would set the
groundwork for framework(s) and solutions that sufficiently address
these limitations.
Copyright Notice...................................................1
1. Introduction....................................................3
2. Definitions and Abbreviations...................................4
2.1 Definitions....................................................4
2.2 Abbreviations..................................................5
3. Common use models and network architecture implications.........5
4. Issues in multicasting related to commercial and large-scale
implementations....................................................7
4.1 Access limits and resource issues..............................7
4.2 Capability to distinguish between receivers (end hosts)........7
4.3 Capability to distinguish between users (as opposed to merely
hosts).............................................................8
4.4 Minimizing Channel Join Latency and Leave Latency..............8
4.5 Surveillance of receiver by sender.............................8
4.5.1 Precise access logging.......................................8
4.5.2 How to share user information................................8
4.5.3 Trustworthy logs to monitor user activity....................9
4.6 Notification to users of the result of the join request........9
4.7 Sharing of Infrastructure for Support of Triple Play Services..9
4.8 DRM Protection.................................................9
5. Description of existing architectures...........................9
5.1 IGMP/MLD......................................................10
5.2 IGMP/MLD plus L2/L3 Authentication with Access Control Policy.11
5.3 Unicast Control with IGMP/MLD.................................13
5.4 IGMP/MLD with Multicast Encryption............................13
6. Evaluation of architectures by issue...........................14
6.1 Access limit capabilities, compared by architecture...........14
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6.2 Capability to distinguish between receivers, compared by
architecture......................................................15
6.3 Capability to distinguish between users, compared by
architecture......................................................16
6.4 Maintain guaranteed quality-level of data delivery (Voice,
Video), compared by architecture..................................17
6.5 Fast leave for fast surfing capability, compared by architecture
..................................................................17
6.6 Surveillance of receiver by sender, compared by architecture..18
6.7 Notification to users of the result of the join request compared
by architecture...................................................19
6.8 Comparison summary............................................19
7. Relevance to non-commercial deployments........................20
8. IANA considerations............................................20
9. Security considerations........................................20
10. Conclusion....................................................20
Normative References..............................................21
Comments..........................................................22
Full Copyright Statement..........................................23
Intellectual Property.............................................23
Expiration........................................................24
Acknowledgement...................................................24
1. Introduction
The intention of this memo is to initiate a discussion on the state
of current multicasting protocols deployed for commercial, large-
scale multicasting and their capabilities to provide receiver access
control. Many of the issues discussed in this memo may be relevant
to non-commercial situations, as well.
Existing IP multicasting protocols (as presented in Section 5) were
designed to meet certain sets of requirements that do not
necessarily include architectural considerations intended to support
commercial services. This memo presents a number of issues network
providers may face when they attempt to apply current multicasting
standards to commercial services. The extent to which existing
multicast protocols can or cannot satisfactorily deal with these
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issues is explored. A few network models based on a range of
different business models are presented as a basis for defining
requirements.
Multicasting can be useful to make the network more scalable when a
large volume of information needs to be distributed to a large
number of receivers. However, multicasting according to current
standards (e.g., IGMPv3[1] and MLDv2[2]) has drawbacks compared to
unicasting in terms of its commercial applicability because of the
insufficiency of access control and protection of network resources
against malicious use or accidents. In order to be applicable to
large-scale commercial networks, multicast networks need to have the
same capabilities which are currently supported by unicast networks.
Such issues which are important to commercial, large-scale
implementations of multicasting are listed. Next, a few possible
existing architectures used for multicasting with access control
based on current standards are presented. Specifically 1) IGMP/ MLD,
2) IGMP/MLD with L2/L3 Authentication with ACL 3) Unicast Control
with IGMP/MLD and 4) IGMP/MLD with Multicast Encryption will each be
presented and described. Each architecture is discussed with
respect to the presented list of issues.
2. Definitions and Abbreviations
2.1 Definitions
For the purposes of this memo the following definitions apply:
Accounting: actions for grasping each user's behavior, when she/he
starts/stops to receive a channel, which channel she/he receives,
etc.
Authentication: action for identifying a user as a genuine one.
Authorization: action for giving permission to access the content or
network to a user.
Receiver: an end-host or end-client which receives content. A
receiver may be distinguishable by a network ID such as MAC address
or IP address.
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Triple Play: voice (VoIP), video, and broadband Internet access
services.
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 purposes of this draft the following abbreviations apply:
ACL: Access Control List
CDS: Content Delivery Services
CP: Content Provider
DRM: Data Rights Management
KEI: Key Exchange Identifier
NSP: Network Service Provider
QoS: Quality of Service
3. Common use models and network architecture implications
Issues such as user identification, access-control, tracking and
billing are common requirements for commercial content delivery
services (CDS) systems (and are important in many non-commercial CDS
systems as well.) These same requirements should be met for CDS
systems that employ multicasting.
In some cases a single entity may design and be responsible for a
system that covers the various common high-level requirements of a
commercial multicasting system such as 1) content serving, 2) the
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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
memo draft-ietf-mboned-maccnt-04.txt [3, referred to hereafter in
this memo as MACCNT-draft] provides more detail of the multiple
versus single entity CDS network model.
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 commercial network service providers do not generally
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 business model of a single network service provider (NSP)
providing multicasting services to multiple content providers CP has
certain implications:
-Need for user tracking and billing capabilities
-Need for network access control and/or 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
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In the next section issues in multicasting related to commercial and
large-scale implementations are presented. Some presented issues
are not pertinent to cases where the NSP and CP are the same entity.
4. Issues in multicasting related to commercial and large-scale
implementations
This section lists issues related to receiver access control in
current multicasting protocols which are especially important to
commercial, large-scale multicasting. To avoid unnecessary
duplication with MACCNT-draft, detail for some of these issues is
provided through references in the Normative Reference section.
4.1 Access limits and resource issues
For commercial applications of multicasting, network and content
providers generally wish to be able to control the number of groups
a host can access at the same time. Also the network provider may
wish to limit the number of users accessing a multicast stream
because of bandwidth and processing issues between the receiver and
the multicast server. This section corresponds to MACCNT-draft[3],
section 4.5.14.2 "Issue of network resource protection", and 4.2.1
"Access control", but provides more detail.
With best-effort services (e.g. mail transfer, web surfing) strict
network resource allocation is not necessary, but for services with
a guaranteed QoS level (e.g. IP television, teleconferencing, VoIP)
it is necessary to allocate sufficient bandwidth and server
resources to each service. More detail on the topic of network
resource protection is provided in section "Issue of network
resource protection" of the MACCNT-draft[3].
4.2 Capability to distinguish between receivers (end hosts)
For detail on the topic on the capability to distinguish between
receivers, refer to MACCNT-draft[3], 4.1 the second paragraph which
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begins with "With current protocols (IGMP/MLD), the sender cannot
distinguish
4.3 Capability to distinguish between users (as opposed to merely
hosts)
Detail related to the topic of user identification can be found in
section "User identification" of the MACCNT-draft[3], the first
paragraph.
4.4 Minimizing Channel Join Latency and Leave Latency
More detail on the topic of channel leave latency is provided in
section "Channel Join Latency and Leave Latency" of the MACCNT-
draft[3].
4.5 Surveillance of receiver by sender
4.5.1 Precise access logging
For detail on the topic please refer to MACCNT-draft[3], 4.6
"Accounting and billing", especially the second paragraph which
begins with " To assemble such..."
4.5.2 How to share user information
For commercial multicast applications where NSP and CP are different
entities, there are a number of issues regarding how to share user
information between the NSP and CP. For example, which entities
should be able to access which information relating to user-based
tracking? What is the user identifier that can be used between the
entities to distinguish among users, and which entities should be
able to recognize this identifier? Another important issue is how
the edge router should be able to access and then maintain user
information. The current situation of present architectures is that
only the NSP can get information about user activity, because user
activities are only observable from join/leave information logged on
edge devices which are under control of the NSP. This section
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corresponds to MACCNT-draft[3], section 4.5.1 "How to share user
information", but provides more detail than in the MACCNT-draft.
4.5.3 Trustworthy logs to monitor user activity
An important issue for commercial multicasting applications is how
the NSP can get trustworthy data on user activity which may be
needed for billing and statistics purposes. A standard way of
logging user activity and protecting the integrity of the logs does
not exist. Often network providers do not want to keep logs on
untrusted user terminals that can be tampered with.
4.6 Notification to users of the result of the join request
Details for this issue are presented in MACCNT-draft[3], section 4.6
"Notification to users of the result of the join request."
4.7 Sharing of Infrastructure for Support of Triple Play Services
As stated in MACCNT-draft[3], section "Small impact on the existing
products": "Ideally the NSP should be able to use the same
infrastructure (such as access control) to support commercial
multicast services for the so-called 'triple play' services".
4.8 DRM Protection
Digital Rights Management (DRM) is important but out of scope of
this memo.
5. Description of existing architectures
In this section, existing architectures used for multicasting based
on current standards are defined. In section 6 these architectures
will be compared by the issues presented in section 4.
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5.1 IGMP/MLD
Internet Group Management Protocol(IGMP) or Multicast Listener
Discovery (MLD) are protocols for layer 3 management of multicasting.
In IP multicast a receiver sends a request to a first-hop multicast
router to join a particular multicast group. The router is then
responsible for forwarding the appropriate data from the sender to
the receiver.
+----------+ +----------+ +----------+ +----------+
| Sender | | Router | | L2SW | | Receiver |
| | | |<---------------1,JOIN--| |
| | | | | | | |
| |--------------------------------2,Data->| |
| | | | | | | |
| | | | | | | |
+----------+ +----------+ +----------+ +----------+
For the sake of simplicity, the above diagram only shows the
sequence of requests for a single receiver. When multiple receivers
are requesting the same channel stream the data would be copied at
the multicasting router to serve the multiple streams.
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5.2 IGMP/MLD plus L2/L3 Authentication with Access Control Policy
With a basic implementation of IGMP/MLD, no authorization is
performed on the receiver. It is possible to combine an IGMP/MLD
implementation with Layer 2 or Layer 3 Authentication to provide an
access-control mechanism at the first point of attachment to the
network, for example, using 802.1X.
For example, a receiver may request to an L2 authentication server
for access to the network. The authentication controller then
queries the policy server with the receiver's credentials (such as
IP or MAC address), and if the receiver is determined to be an
authorized user of the network ("success"), the router downloads the
ACL from the policy server. For example, users which are not on the
ACL are rejected. Then the Layer 2 Switch is directed to open a
port for the receiver to send a join request to the multicast router.
The router is then responsible for forwarding the appropriate data
from the sender to the receiver.
Note: ACL is one existing method to realize an access control policy.
Other methods exist.
+----------+
| Policy |
| Server |\
| | \
+----------+ \ 4,ACL Download
| ^ \
| | \
V | V
+----------+ +----------+ +----------+ +----------+
| L2 | | Router | | L2SW | | Receiver |
| | | | | | | |
| Auth. |<---------------------------- 1,Request-| |
| | | | | | | |
| |--------2,Success------------>X(3,Auth) | |
+----------+ | | | | | |
| | | | | |
+----------+ | | | | | |
| | | |<---------------5,Join---| |
| Sender | | | | | | |
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| |------------>x------------------6,Data-->| |
| | | | | | | | |
+----------+ +--------|-+ +----------+ +----------+
|
V
Key:
Auth: Authentication
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5.3 Unicast Control with IGMP/MLD
The receiver first sends a unicast request to the sender which
resides in the CP's domain. This method is the same as that used in
unicast video-on-demand (VoD) systems. If authorization is
successful the sender sends the multicast address information via
unicast. With this multicast address the receiver does a IGMP\MLD
join as in described in 5.1. Generally this approach is relying on
either some sort of content encryption or "security through
obscurity" for content security. Also accounting becomes problematic
because user credentials may not be identified.
+----------+ +----------+ +----------+ +----------+
| Sender | | Router | | L2SW | | Receiver |
| | | | | | | |
| |<------------------------------1,Request-| |
| | | | | | | |
| |-------------------------------2,Success>| |
| | | | | | | |
| | | |<--------------3,Join----| |
| | | | | | | |
| |------------>x-----------------4,Data--->| |
| | | | | | | | |
| | | | | | | | |
+----------+ +--------|-+ +----------+ +----------+
|
V
5.4 IGMP/MLD with Multicast Encryption
With a basic implementation of IGMP/MLD, no data protection is
performed on data sent to the receiver. No credential check is
performed on the receiver and any receiver can receive and use the
data. The IGMP/MLD with Multicast Encryption model assumes that the
sender is sending encrypted data and that for this data to be useful
to the receiver it must first request and receive a key from a group
controller and key server that is synchronized with the content
encryption occurring on the sender's data.
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+----------+ +----------+ +----------+ +----------+
| G.C. & | | Router | | L2SW | | Receiver |
| | | | | | | |
| Key S. |<------------------------------1,Request-| |
| | | | | | | |
| |-------------------------------2,Key---->| |
+----------+ | | | | | |
| | | | | |
+----------+ | | | | | |
| | | |<---------------3,Join---| |
| Sender | | | | | | |
| |------------>x------------------4,Data-->| |
| | | | | | | | |
+----------+ +--------|-+ +----------+ +----------+
|
V
Key:
G.C. & Key S.= Group Controller and Key Server
6. Evaluation of architectures by issue
In this section the various issues raised in section four are
analyzed by each of the architectures introduced in section five.
6.1 Access limit capabilities, compared by architecture
Comparison of currently available architectures with respect to
limiting the access of multicast groups
- IGMP/MLD: It is not possible to limit data reception.
- L2/L3 authentication with access control policy:
With an ACL it is possible to limit access of multicast groups.
However it should be discussed as to how scalable this approach is
because configuring an ACL could be a labor-intensive task.
- IGMP/MLD with Unicast control
It is possible for malicious users to reconfigure the receiver's
terminal to ignore the Unicast control. In this case, this
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maliciously reconfigured terminal could send a join message even if
it is rejected by the network. In such a case, the ineligible
receiver would be able to receive the multicast. As such, this
method may not be strong enough to exclude ineligible access.
-Multicast Encryption:
It is possible for receivers to receive IP packets, even if they do
not possess the keys to decrypt them. A receiver may also be able to
store such received data until they discover a way to decrypt it.
Another disadvantage of this method is that network resources are
wasted if an ineligible receiver receives an encrypted content even
if they do not have a valid key.
6.2 Capability to distinguish between receivers, compared by
architecture
Comparison of currently possible protocol-based solutions.
-IGMP/MLD:
The sender has no direct line of contact with the receiver and
therefore cannot distinguish on a receiver-basis. (If the edge-
router's user interface is statically assigned then the interface's
log can be used to track joins, but this would mean portability is
sacrificed. Moreover, this method is not applicable to a case where
the CP and NSP are different companies because the CP cannot access
this join-log. Sharing of the join-log could be done with a yet-to-
be defined standard mechanism/format. )
-L2/L3 authentication with access control policy:
At the moment of L2/L3 authentication it is possible to recognize
receivers, but if there are multiple content providers (CP) a single
L2 Authorization Server cannot distinguish among the CPs. Therefore
it would be necessary to gather the join logs. (If the interface is
fixed then the join-log can be used, but this would mean portability
is sacrificed. Moreover, this method is not applicable to a case
where the CP and NSP are different companies because the CP cannot
access this join-log.)
-IGMP/MLD with Unicast control :
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It is possible to distinguish among receivers using Unicast control.
This latency may not be a problem when users are switching between
channels of the same CP in cases where the CP grants viewing
privileges uniformly across all of its channels. However, other
policies are possible that may be on a channel-basis, time-basis,
etc. and in such cases channel changing has latency issues.
-Multicast Encryption:
If the CP maintains the Key Server it is possible to distinguish on
the receiver-level. If the Network Service Provider maintains the
key server it is necessary to devise a method for the NSP to notify
the CP.
6.3 Capability to distinguish between users, compared by architecture
Comparison of currently possible protocol-based solutions:
-IGMP/MLD:
Since there is no user-based information, it is not possible to
distinguish on the user-level.
-L2/L3 authentication with access control policy:
At the moment of L2/L3 Authentication it is possible to distinguish
on the user-level.
However it is difficult to combine user and group logs: it would be
necessary to match user IDs from L2-Auth logs and group IDs from the
Join logs to match users and groups.
-IGMP/MLD with unicast control :
Distinguishing by user is possible using unicast control.
-Multicast Encryption:
If the Content Provider manages the Key Server it is possible to
distinguish the user.
If the Network Service Provider manages the Key Server it is
necessary to notify the Content Provider.
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6.4 Maintain guaranteed quality-level of data delivery (Voice, Video),
compared by architecture
Comparison of currently possible protocol-based solutions:
-IGMP/MLD:
It is not possible to reject a user attempting to access even if
there are not sufficient resources.
-L2/L3 authentication with access control policy:
The AAA server does not know whether there are sufficient resources
or not. This method still can provide a guaranteed QoS if every
channel has the same bandwidth and sufficient bandwidth are
allocated to each user beforehand. However, it is not possible to
provide a guaranteed QoS by comparing the available bandwidth and
the necessary bandwidth upon each user's request.
-IGMP/MLD with Unicast control:
When the CP and NSP are separate entities it is not possible for the
CP to make a proper authorization decision because only the NSP
grasps the network resource availability.
-Multicast Encryption:
Having only encryption provides no access control and therefore
provides no mechanism to reject a user attempt to access when
sufficient resources are not available (i.e. the user can receive
data even without holding a valid key.)
6.5 Fast leave for fast surfing capability, compared by architecture
Comparison of currently possible protocol-based solutions:
-IGMP/MLD:
It is possible to track on a per host level (based on host address)
therefore fast leave for fast surfing capability can be achieved.
-L2/L3 authentication with access control policy:
It is possible to track on a per host level (based on host address)
therefore fast leave for fast surfing capability can be achieved.
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-IGMP/MLD with Unicast control :
Even if a quick leave is possible, changing to a new channel using
Unicast Control is slow (latency problem). This latency may not be
a problem when users are switching between channels of the same CP
in cases where the CP grants viewing privileges uniformly across all
of its channels. However, other policies are possible that may be
on a channel-basis, time-basis, etc. and in such cases channel
changing has latency issues.
-Multicast Encryption:
Even if a quick leave is possible, delivery of the Key Exchange
Identifier(KEI) is slow.
6.6 Surveillance of receiver by sender, compared by architecture
Comparison of currently possible protocol-based solutions:
-IGMP/MLD:
With this protocol it is possible to separately log join and leave
actions, but it is difficult to match these join and leave actions
because analyzing the logs requires heavy computation (related to
the scalability with millions of users).
-L2/L3 authentication with access control policy:
In this solution, the leave action is not recorded unless some
additional mechanism such as IGMP/MLD snooping is used. In some
cases, users disconnect their terminals without sending logout
messages. Also it is possible that the user is running multiple
services and thus they will not log out even if they are finished
watching video or other multicast content. In this case, it is not
possible to precisely determine for accounting purposes when each
user disconnected. Also, it may be a problem that unused bandwidth
is being needlessly reserved.
However MLD/IGMP reports/joins need to be refreshed periodically.
The ACL entry can be deactivated if the user no longer refreshes the
report/join, but this means that user can be charged with unwatched
programs (125 seconds default.) This lack of precise timing may be a
problem in certain cases such as for paid services.
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-IGMP/MLD with Unicast control :
In this solution the leave action is not recorded.
-Multicast Encryption:
If logs are recorded for each renewal of keys, then it is possible
to track activity on a per-user basis. However if logs are only
recorded per content data download then such tracking is not
possible.
It should be noted that authentication of the source of each
join/leave message is important.
6.7 Notification to users of the result of the join request compared by
architecture
Comparison of currently possible protocol-based solutions:
-IGMP/MLD:
After the join it is not possible to notify the user of the result
of the join request.
-L2/L3 authentication with access control policy:
After the join it is not possible to notify the user of the result
of the join request.
-IGMP/MLD with Unicast control :
After the join it is not possible to notify the user of the result
of the join request.
-Multicast Encryption:
After the join it is not possible to notify the user of the result
of the join request.
6.8 Comparison summary
In this section a variety of existing architectures used for
multicasting based on current standards were compared and evaluated.
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None of these architectures can sufficiently meet all of the common
requirements for accounting, authentication and authorization in
commercial, large-scale IP multicasting. Therefore it is
recommended that framework(s) for sufficiently addressing such
requirements be explored.
7. Relevance to non-commercial deployments
While the impetus for this memo was to discuss issues related to the
state of current multicasting protocols deployed for commercial,
large-scale multicasting and their capabilities to provide receiver
access control. Many of the issues discussed in this memo may be
relevant to non-commercial situations, as well.
8. IANA considerations
This memo does not raise any IANA consideration issues.
9. Security considerations
This memo does not raise any new security issues which are not
already existing in original protocols. Enhancement of multicast
access control capabilities may enhance security performance.
10. Conclusion
Issues such as user identification, access-control, tracking and
billing are common requirements for many content delivery services
(CDS) systems. When CDS systems employ multicasting with
architectures based on currently existing multicasting standards, it
is often necessary to deploy non-standardized solutions to meet
these common requirements. It is recommended that requirements be
defined to set the groundwork for creating framework(s) and
solutions that address the various issues discussed in this memo
which are limiting the application of multicasting especially to
commercial, large-scale CDS services. Such requirements should take
into consideration a range of possible architectures based on
multiple business or usage models.
Hayashi, He, Satou, Ohta, Vaidya [Page 20]
Internet Draft draft-ietf-mboned-rac-issues-03.txt April, 2006
Normative References
[1] B. Cain, et. al., "Internet Group Management Protocol, Version
3", RFC3376, October 2002.
[2] R. Vida, et. al., "Multicast Listener Discovery Version 2
(MLDv2) for IPv6", RFC3810, June 2004.
[3] Hayashi, et. al., "Accounting, Authentication and Authorization
Issues in Well Managed IP Multicasting Services", draft-ietf-
mboned-maccnt-req-04.txt, February 2006 [Work in Progress].
Authors' Addresses
Tsunemasa Hayashi
NTT Network Innovation Laboratories
1-1 Hikari-no-oka, Yokosuka-shi, Kanagawa, 239-0847 Japan
Phone: +81 46 859 8790
Email: hayashi.tsunemasa@lab.ntt.co.jp
Haixiang He
Nortel Networks
600 Technology Park Drive
Billerica, MA 01801, USA
Phone: +1 978 288 7482
Email: haixiang@nortelnetworks.com
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
Susheela Vaidya
Hayashi, He, Satou, Ohta, Vaidya [Page 21]
Internet Draft draft-ietf-mboned-rac-issues-03.txt April, 2006
Cisco Systems, Inc.
170 W. Tasman Drive
San Jose, CA 95134
Phone: +1-408-525-1952
Email: svaidya@cisco.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.
Hayashi, He, Satou, Ohta, Vaidya [Page 22]
Internet Draft draft-ietf-mboned-rac-issues-03.txt April, 2006
Full Copyright Statement
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Hayashi, He, Satou, Ohta, Vaidya [Page 23]
Internet Draft draft-ietf-mboned-rac-issues-03.txt Aprilh, 2006
Expiration
This Internet-Draft will expire on October 21, 2006.
Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
Hayashi, He, Satou, Ohta, Vaidya [Page 24]
