draft-tarapore-mboned-multicast-cdni-04.txt   draft-tarapore-mboned-multicast-cdni-05.txt 
MBONED Working Group Percy S. Tarapore MBONED Working Group Percy S. Tarapore
Internet Draft Robert Sayko Internet Draft Robert Sayko
Intended status: BCP AT&T Intended status: BCP AT&T
Expires: April 21, 2014 Greg Shepherd Expires: August 3, 2014 Greg Shepherd
Toerless Eckert Toerless Eckert
Cisco Cisco
Ram Krishnan Ram Krishnan
Brocade Brocade
October 21, 2013 March 3, 2014
Multicasting Applications Across Inter-Domain Peering Points Multicasting Applications Across Inter-Domain Peering Points
draft-tarapore-mboned-multicast-cdni-04.txt draft-tarapore-mboned-multicast-cdni-05.txt
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
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This Internet-Draft will expire on April 21, 2014. This Internet-Draft will expire on August 3, 2014.
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This document may contain material from IETF Documents or IETF This document may contain material from IETF Documents or IETF
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3. Inter-domain Peering Point Requirements for Multicast..........5 3. Inter-domain Peering Point Requirements for Multicast..........5
3.1. Native Multicast..........................................5 3.1. Native Multicast..........................................5
3.2. Peering Point Enabled with GRE Tunnel.....................6 3.2. Peering Point Enabled with GRE Tunnel.....................6
3.3. Peering Point Enabled with an AMT - Both Domains Multicast 3.3. Peering Point Enabled with an AMT - Both Domains Multicast
Enabled........................................................8 Enabled........................................................8
3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast
Enabled........................................................9 Enabled........................................................9
3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through
AD-2..........................................................11 AD-2..........................................................11
4. Supporting Functionality......................................13 4. Supporting Functionality......................................13
4.1. Network Transport and Security Guidelines................14 4.1. Network Interconnection Transport and Security Guidelines14
4.2. Routing Aspects and Related Guidelines...................14 4.2. Routing Aspects and Related Guidelines...................15
4.3. Back Office Functions - Billing and Logging Guidelines...14 4.2.1 Native Multicast Routing Aspects..................15
4.4. Operations - Service Performance and Monitoring Guidelines14 4.2.2 GRE Tunnel over Interconnecting Peering Point.....16
4.5. Reliability Models/Service Assurance Guidelines..........14 4.2.3 Routing Aspects with AMT Tunnels.....................16
4.6. Provisioning Guidelines..................................14 4.3. Back Office Functions - Billing and Logging Guidelines...19
4.7. Client Models............................................14 4.4. Operations - Service Performance and Monitoring Guidelines19
4.8. Addressing Guidelines....................................14 4.5. Reliability Models/Service Assurance Guidelines..........19
5. Security Considerations.......................................15 4.6. Provisioning Guidelines..................................19
6. IANA Considerations...........................................15 4.7. Client Models............................................19
7. Conclusions...................................................15 4.8. Addressing Guidelines....................................19
8. References....................................................15 5. Security Considerations.......................................19
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8.1. Normative References.....................................15 6. IANA Considerations...........................................20
8.2. Informative References...................................15 7. Conclusions...................................................20
9. Acknowledgments...............................................15 8. References....................................................20
8.1. Normative References.....................................20
8.2. Informative References...................................20
9. Acknowledgments...............................................20
1. Introduction 1. Introduction
Several types of applications (e.g., live video streaming, software Several types of applications (e.g., live video streaming, software
downloads) are well suited for delivery via multicast means. The use downloads) are well suited for delivery via multicast means. The use
of multicast for delivering such applications offers significant of multicast for delivering such applications offers significant
savings for utilization of resources in any given administrative savings for utilization of resources in any given administrative
domain. End user demand for such applications is growing. Often, domain. End user demand for such applications is growing. Often,
this requires transporting such applications across administrative this requires transporting such applications across administrative
domains via inter-domain peering points. domains via inter-domain peering points.
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o Multicast Listener Discovery (MLD) [RFC4604] o Multicast Listener Discovery (MLD) [RFC4604]
This document therefore serves the purpose of a "Gap Analysis" This document therefore serves the purpose of a "Gap Analysis"
exercise for this process. The rectification of any gaps identified exercise for this process. The rectification of any gaps identified
- whether they involve protocol extension development or otherwise - - whether they involve protocol extension development or otherwise -
is beyond the scope of this document and is for further study. is beyond the scope of this document and is for further study.
2. Overview of Inter-domain Multicast Application Transport 2. Overview of Inter-domain Multicast Application Transport
A multicast-based application delivery scenario is as follows: A multicast-based application delivery scenario is as follows:
o Two independent administrative domains are interconnected via a
peering point.
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o Two independent administrative domains are interconnected via a
peering point.
o The peering point is either multicast enabled (end-to-end o The peering point is either multicast enabled (end-to-end
native multicast across the two domains) or it is connected by native multicast across the two domains) or it is connected by
one of two possible tunnel types: one of two possible tunnel types:
o A Generic Routing Encapsulation (GRE) Tunnel [RFC2784] o A Generic Routing Encapsulation (GRE) Tunnel [RFC2784]
allowing multicast tunneling across the peering point, or allowing multicast tunneling across the peering point, or
o An Automatic Multicast Tunnel (AMT) [IETF-ID-AMT]. o An Automatic Multicast Tunnel (AMT) [IETF-ID-AMT].
o The application stream originates at a source in Domain 1. o The application stream originates at a source in Domain 1.
o An End User associated with Domain 2 requests the application. o An End User associated with Domain 2 requests the application.
It is assumed that the application is suitable for delivery via It is assumed that the application is suitable for delivery via
multicast means (e.g., live steaming of major events, software multicast means (e.g., live steaming of major events, software
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Enterprise case. Enterprise case.
The Use Cases describing various architectural configurations for The Use Cases describing various architectural configurations for
the multicast distribution along with associated requirements is the multicast distribution along with associated requirements is
described in section 3. Unique aspects related to the Enterprise described in section 3. Unique aspects related to the Enterprise
network possibility will be described in this section. A network possibility will be described in this section. A
comprehensive list of pertinent information that needs to be comprehensive list of pertinent information that needs to be
exchanged between the two domains to support various functions exchanged between the two domains to support various functions
enabling the application transport is provided in section 4. enabling the application transport is provided in section 4.
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3. Inter-domain Peering Point Requirements for Multicast 3. Inter-domain Peering Point Requirements for Multicast
The transport of applications using multicast requires that the The transport of applications using multicast requires that the
inter-domain peering point is enabled to support such a process. inter-domain peering point is enabled to support such a process.
There are three possible Use Cases for consideration. There are three possible Use Cases for consideration.
3.1. Native Multicast 3.1. Native Multicast
This Use Case involves end-to-end Native Multicast between the two This Use Case involves end-to-end Native Multicast between the two
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Advantages of this configuration are: Advantages of this configuration are:
o Most efficient use of bandwidth in both domains o Most efficient use of bandwidth in both domains
o Fewer devices in the path traversed by the multicast stream o Fewer devices in the path traversed by the multicast stream
when compared to unicast transmissions. when compared to unicast transmissions.
From the perspective of AD-1, the one disadvantage associated with From the perspective of AD-1, the one disadvantage associated with
native multicast into AD-2 instead of individual unicast to every EU native multicast into AD-2 instead of individual unicast to every EU
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in AD-2 is that it does not have the ability to count the number of in AD-2 is that it does not have the ability to count the number of
End Users as well as the transmitted bytes delivered to them. This End Users as well as the transmitted bytes delivered to them. This
information is relevant from the perspective of customer billing and information is relevant from the perspective of customer billing and
operational logs. It is assumed that such data will be collected by operational logs. It is assumed that such data will be collected by
the application layer. The application layer mechanisms for the application layer. The application layer mechanisms for
generating this information need to be robust enough such that all generating this information need to be robust enough such that all
pertinent requirements for the source provider and the AD operator pertinent requirements for the source provider and the AD operator
are satisfactorily met. The specifics of these methods are beyond are satisfactorily met. The specifics of these methods are beyond
the scope of this document. the scope of this document.
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3.2. Peering Point Enabled with GRE Tunnel 3.2. Peering Point Enabled with GRE Tunnel
The peering point is not native multicast enabled in this Use Case. The peering point is not native multicast enabled in this Use Case.
There is a Generic Routing Encapsulation Tunnel provisioned over the There is a Generic Routing Encapsulation Tunnel provisioned over the
peering point. In this case, the interconnection I1 between AD-1 and peering point. In this case, the interconnection I1 between AD-1 and
AD-2 in Figure 1 is multicast enabled via a Generic Routing AD-2 in Figure 1 is multicast enabled via a Generic Routing
Encapsulation Tunnel (GRE) [RFC2784] and encapsulating the multicast Encapsulation Tunnel (GRE) [RFC2784] and encapsulating the multicast
protocols across the interface. The routing configuration is protocols across the interface. The routing configuration is
basically unchanged: Instead of BGP (SAFI2) across the native IP basically unchanged: Instead of BGP (SAFI2) across the native IP
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multicast link between AD-1 and AD-2, BGP (SAFI2) is now run across multicast link between AD-1 and AD-2, BGP (SAFI2) is now run across
the GRE tunnel. the GRE tunnel.
Advantages of this configuration: Advantages of this configuration:
o Highly efficient use of bandwidth in both domains although not o Highly efficient use of bandwidth in both domains although not
as efficient as the fully native multicast Use Case. as efficient as the fully native multicast Use Case.
o Fewer devices in the path traversed by the multicast stream o Fewer devices in the path traversed by the multicast stream
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e. GRE tunnels are typically configured manually between peering e. GRE tunnels are typically configured manually between peering
points to support multicast delivery between domains. points to support multicast delivery between domains.
f. It is recommended that the GRE tunnel (tunnel server) f. It is recommended that the GRE tunnel (tunnel server)
configuration in the source network is such that it only configuration in the source network is such that it only
advertises the routes to the content sources and not to the advertises the routes to the content sources and not to the
entire network. This practice will prevent unauthorized entire network. This practice will prevent unauthorized
delivery of content through the tunnel (e.g., if content is not delivery of content through the tunnel (e.g., if content is not
part of an agreed CDN partnership). part of an agreed CDN partnership).
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3.3. Peering Point Enabled with an AMT - Both Domains Multicast 3.3. Peering Point Enabled with an AMT - Both Domains Multicast
Enabled Enabled
Both administrative domains in this Use Case are assumed to be Both administrative domains in this Use Case are assumed to be
native multicast enabled here; however the peering point is not. The native multicast enabled here; however the peering point is not. The
peering point is enabled with an Automatic Multicast Tunnel. The peering point is enabled with an Automatic Multicast Tunnel. The
basic configuration is depicted in Figure 2. basic configuration is depicted in Figure 2.
------------------- ------------------- ------------------- -------------------
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implement. Attractive properties of AMT include the following: implement. Attractive properties of AMT include the following:
o Dynamic interconnection between Gateway-Relay pair across o Dynamic interconnection between Gateway-Relay pair across
the peering point. the peering point.
o Ability to serve clients and servers with differing o Ability to serve clients and servers with differing
policies. policies.
Disadvantages of this configuration: Disadvantages of this configuration:
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o Per Use Case 3.1 (AD-2 is native multicast), current router o Per Use Case 3.1 (AD-2 is native multicast), current router
technology cannot count the number of end users or the number technology cannot count the number of end users or the number
bytes transmitted. bytes transmitted.
o Additional devices (AMT Gateway and Relay pairs) may be o Additional devices (AMT Gateway and Relay pairs) may be
introduced into the path if these services are not incorporated introduced into the path if these services are not incorporated
in the existing routing nodes. in the existing routing nodes.
o Currently undefined mechanisms to select the AR from the AG o Currently undefined mechanisms to select the AR from the AG
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across the peering points once the Gateway in AD-2 receives the across the peering points once the Gateway in AD-2 receives the
(S, G) information from the EU. (S, G) information from the EU.
3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast Enabled 3.4. Peering Point Enabled with an AMT - AD-2 Not Multicast Enabled
In this AMT Use Case, the second administrative domain AD-2 is not In this AMT Use Case, the second administrative domain AD-2 is not
multicast enabled. This implies that the interconnection between AD- multicast enabled. This implies that the interconnection between AD-
2 and the End User is also not multicast enabled as depicted in 2 and the End User is also not multicast enabled as depicted in
Figure 3. Figure 3.
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------------------- ------------------- ------------------- -------------------
/ AD-1 \ / AD-2 \ / AD-1 \ / AD-2 \
/ (Multicast Enabled) \ / (Non-Multicast \ / (Multicast Enabled) \ / (Non-Multicast \
/ \ / Enabled) \ / \ / Enabled) \
| +----+ | | | | +----+ | | |
| | | +------+ | | | +----+ | | | +------+ | | | +----+
| | CS |------>| AR |-|---------|-----------------------|-->|EU/G| | | CS |------>| AR |-|---------|-----------------------|-->|EU/G|
| | | +------+ | | |I2 +----+ | | | +------+ | | |I2 +----+
\ +----+ / \ / \ +----+ / \ /
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o Dynamic interconnection between Gateway-Relay pair across o Dynamic interconnection between Gateway-Relay pair across
the peering point. the peering point.
o Ability to serve clients and servers with differing o Ability to serve clients and servers with differing
policies. policies.
o Each AMT tunnel serves as a count for each End User and is also o Each AMT tunnel serves as a count for each End User and is also
able to track data usage (bytes) delivered to the EU. able to track data usage (bytes) delivered to the EU.
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Disadvantages of this configuration: Disadvantages of this configuration:
o Additional devices (AMT Gateway and Relay pairs) are introduced o Additional devices (AMT Gateway and Relay pairs) are introduced
into the transport path. into the transport path.
o Assuming multiple peering points between the domains, the EU o Assuming multiple peering points between the domains, the EU
Gateway needs to be able to find the "correct" AMT Relay in AD- Gateway needs to be able to find the "correct" AMT Relay in AD-
1. 1.
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G) information to the Gateway for this purpose. G) information to the Gateway for this purpose.
e. The AMT tunnel capabilities are expected to be sufficient for e. The AMT tunnel capabilities are expected to be sufficient for
the purpose of collecting relevant information on the multicast the purpose of collecting relevant information on the multicast
streams delivered to End Users in AD-2. streams delivered to End Users in AD-2.
3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through AD-2 3.5. AD-2 Not Multicast Enabled - Multiple AMT Tunnels Through AD-2
This is a variation of Use Case 3.4 as follows: This is a variation of Use Case 3.4 as follows:
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------------------- ------------------- ------------------- -------------------
/ AD-1 \ / AD-2 \ / AD-1 \ / AD-2 \
/ (Multicast Enabled) \ / (Non-Multicast \ / (Multicast Enabled) \ / (Non-Multicast \
/ \ / Enabled) \ / \ / Enabled) \
| +----+ | |+--+ +--+ | | +----+ | |+--+ +--+ |
| | | +------+ | ||AG| |AG| | +----+ | | | +------+ | ||AG| |AG| | +----+
| | CS |------>| AR |-|-------->||AR|------------->|AR|-|-->|EU/G| | | CS |------>| AR |-|-------->||AR|------------->|AR|-|-->|EU/G|
| | | +------+ | I1 ||1 | I2 |2 | |I3 +----+ | | | +------+ | I1 ||1 | I2 |2 | |I3 +----+
\ +----+ / \+--+ +--+ / \ +----+ / \+--+ +--+ /
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AD-2. An AMT node comprises co-location of an AMT Gateway and AD-2. An AMT node comprises co-location of an AMT Gateway and
an AMT Relay. One such node is at the AD-2 side of the peering an AMT Relay. One such node is at the AD-2 side of the peering
point (node AGAR1 in Figure 4). point (node AGAR1 in Figure 4).
o Single AMT tunnel established across peering point linking AMT o Single AMT tunnel established across peering point linking AMT
Relay in AD-1 to the AMT Gateway in the AMT node AGAR1 in AD-2. Relay in AD-1 to the AMT Gateway in the AMT node AGAR1 in AD-2.
o AMT tunnels linking AMT node AGAR1 at peering point in AD-2 to o AMT tunnels linking AMT node AGAR1 at peering point in AD-2 to
other AMT nodes located at the edges of AD-2: e.g., AMT tunnel other AMT nodes located at the edges of AD-2: e.g., AMT tunnel
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I2 linking AMT Relay in AGAR1 to AMT Gateway in AMT node AGAR2 I2 linking AMT Relay in AGAR1 to AMT Gateway in AMT node AGAR2
in Figure 4. in Figure 4.
o AMT tunnels linking EU device (via Gateway client embedded in o AMT tunnels linking EU device (via Gateway client embedded in
device) and AMT Relay in appropriate AMT node at edge of AD-2: device) and AMT Relay in appropriate AMT node at edge of AD-2:
e.g., I3 linking EU Gateway in device to AMT Relay in AMT node e.g., I3 linking EU Gateway in device to AMT Relay in AMT node
AGAR2. AGAR2.
The advantage for such a chained set of AMT tunnels is that the The advantage for such a chained set of AMT tunnels is that the
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4. Supporting Functionality 4. Supporting Functionality
Supporting functions and related interfaces over the peering point Supporting functions and related interfaces over the peering point
that enable the multicast transport of the application are listed in that enable the multicast transport of the application are listed in
this section. Critical information parameters that need to be this section. Critical information parameters that need to be
exchanged in support of these functions are enumerated along with exchanged in support of these functions are enumerated along with
guidelines as appropriate. Specific interface functions for guidelines as appropriate. Specific interface functions for
consideration are as follows. consideration are as follows.
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4.1. Network Transport and Security Guidelines 4.1. Network Interconnection Transport and Security Guidelines
The term "Network Interconnection Transport" refers to the
interconnection points between the two Administrative Domains. The
following is a representative set of attributes that will need to be
agreed to between the two administrative domains to support
multicast delivery.
o Number of Peering Points
o Peering Point Addresses and Locations
o Connection Type - Dedicated for Multicast delivery or shared
with other services
o Connection Mode - Direct connectivity between the two AD's or
via another ISP
o Peering Point Protocol Support - Multicast protocols that will
be used for multicast delivery will need to be supported at
these points. Examples of protocols include eBGP, BGMP, and
MBGP.
o Bandwidth Allocation - If shared with other services, then
there needs to be a determination of the share of bandwidth
reserved for multicast delivery.
o QoS Requirements - Delay/latency specifications that need to be
specified in an SLA.
o AD Roles and Responsibilities - the role played by each AD for
provisioning and maintaining the set of peering points to
support multicast delivery.
From a security perspective, it is expected that normal/typical
security procedures will be followed by each AD to facilitate
multicast delivery to registered and authenticated end users. Some
security aspects for consideration are:
o Encryption - Peering point links may be encrypted per agreement
if dedicated for multicast delivery.
o Security Breach Mitigation Plan - In the event of a security
breach, the two AD's are expected to have a mitigation plan for
shutting down the peering point and directing multicast traffic
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over alternated peering points. It is also expected that
appropriate information will be shared for the purpose of
securing the identified breach.
4.2. Routing Aspects and Related Guidelines 4.2. Routing Aspects and Related Guidelines
The main objective for multicast delivery routing is to ensure that
the End User receives the multicast stream from the "most optimal"
source [INF_ATIS_10] which typically:
o Maximizes the multicast portion of the transport and minimizes
any unicast portion of the delivery, and
o Minimizes the overall combined network(s) route distance.
This routing objective applies to both Native and AMT; the actual
methodology of the solution will be different for each. Regardless,
the routing solution is expected to be:
o Scalable
o Avoid/minimize new protocol development or modifications, and
o Be robust enough to achieve high reliability and automatically
adjust to changes/problems in the multicast infrastructure.
For both Native and AMT environments, having a source as close as
possible to the EU network is most desirable; therefore, in some
cases, an AD may prefer to have multiple sources near different
peering points, but that is entirely an implementation issue.
4.2.1 Native Multicast Routing Aspects
Native multicast simply requires that the Administrative Domains
coordinate and advertise the correct source address(es) at their
network interconnection peering points(i.e., border routers). An
example of multicast delivery via a Native Multicast process across
two administrative Domains is as follows assuming that the
interconnecting peering points are also multicast enabled:
o Appropriate information is obtained by the EU client who is a
subscriber to AD-2 (see Use Case 3.1). This is usually done via
an appropriate file transfer - this file is typically known as
the manifest file. It contains instructions directing the EU
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client to launch an appropriate application if necessary, and
also additional information for the application about the source
location and the group (or stream) id in the form of the "S,G"
data. The "S" portion provides the name or IP address of the
source of the multicast stream. The file may also contain
alternate delivery information such as specifying the unicast
address of the stream.
o The client uses the join message with S,G to join the multicast
stream [RFC2236].
To facilitate this process, the two AD's need to do the following:
o Advertise the source id(s) over the Peering Points
o Exchange relevant Peering Point information such as Capacity
and Utilization (Other??)
4.2.2 GRE Tunnel over Interconnecting Peering Point
If the interconnecting peering point is not multicast enabled and
both ADs are multicast enabled, then a simple solution is to
provision a GRE tunnel between the two ADs - see Use Case 3.2.2.
The termination points of the tunnel will usually be a network
engineering decision, but generally will be between the border
routers or even between the AD 2 border router and the AD 1 source
(or source access router). The GRE tunnel would allow end-to-end
native multicast or AMT multicast to traverse the interface.
Coordination and advertisement of the source IP is still required.
The two AD's need to follow the same process as described in 4.2.1
to facilitate multicast delivery across the Peering Points.
4.2.3 Routing Aspects with AMT Tunnels
Unlike Native (with or without GRE), an AMT Multicast environment is
more complex. It presents a dual layered problem because there are
two criteria that should be simultaneously meet:
o Find the closest AMT relay to the end-user that also has
multicast connectivity to the content source and
o Minimize the AMT unicast tunnel distance.
There are essentially two components to the AMT specification:
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o AMT Relays: These serve the purpose of tunneling UDP multicast
traffic to the receivers (i.e., End Points). The AMT Relay will
receive the traffic natively from the multicast media source and
will replicate the stream on behalf of the downstream AMT
Gateways, encapsulating the multicast packets into unicast
packets and sending them over the tunnel toward the AMT Gateway.
In addition, the AMT Relay may perform various usage and
activity statistics collection. This results in moving the
replication point closer to the end user, and cuts down on
traffic across the network. Thus, the linear costs of adding
unicast subscribers can be avoided. However, unicast replication
is still required for each requesting endpoint within the
unicast-only network.
o AMT Gateway (GW): The Gateway will reside on an on End-Point -
this may be a Personal Computer (PC) or a Set Top Box (STB). The
AMT Gateway receives join and leave requests from the
Application via an Application Programming Interface (API). In
this manner, the Gateway allows the endpoint to conduct itself
as a true Multicast End-Point. The AMT Gateway will encapsulate
AMT messages into UDP packets and send them through a tunnel
(across the unicast-only infrastructure) to the AMT Relay.
The simplest AMT Use Case (section 3.3) involves peering points that
are not multicast enabled between two multicast enabled ADs. An AMT
tunnel is deployed between an AMT Relay on the AD 1 side of the
peering point and an AMT Gateway on the AD 2 side of the peering
point. One advantage to this arrangement is that the tunnel is
established on an as needed basis and need not be a provisioned
element. The two ADs can coordinate and advertise special AMT Relay
Anycast addresses with each other - though they may alternately
decide to simply provision Relay addresses, though this would not be
a optimal solution in terms of scalability.
Use Cases 3.4 and 3.5 describe more complicated AMT situations as
AD-2 is not multicast enabled. For these cases, the End User device
needs to be able to setup an AMT tunnel in the most optimal manner.
Using an Anycast IP address for AMT Relays allows for all AMT
Gateways to find the "closest" AMT Relay - the nearest edge of the
multicast topology of the source. An example of a basic delivery
via an AMT Multicast process for these two Use Cases is as follows:
o The manifest file is obtained by the EU client application. This
file contains instructions directing the EU client to an ordered
list of particular destinations to seek the requested stream and,
for multicast, specifies the source location and the group (or
stream) ID in the form of the "S,G" data. The "S" portion provides
IETF I-D Multicasting Applications Across Peering Points February 2014
the URI (name or IP address) of the source of the multicast stream
and the "G" identifies the particular stream originated by that
source. The manifest file may also contain alternate delivery
information such as the address of the unicast form of the content
to be used, for example, if the multicast stream becomes
unavailable.
o Using the information in the manifest file, and possibly
information provisioned directly in the EU client, a DNS query is
initiated in order to connect the EU client/AMT Gateway to an AMT
Relay.
o Query results are obtained, and may return an Anycast address or a
specific unicast address of a relay. Multiple relays will
typically exist. The Anycast address is a routable "pseudo-
address" shared among the relays that can gain multicast access to
the source.
o If a specific IP address unique to a relay was not obtained, the
AMT Gateway then sends a message (e.g., the discovery message) to
the Anycast address such that the network is making the routing
choice of particular relay - e.g., closest relay to the EU. (Note
that in IPv6 there is a specific Anycast format and Anycast is
inherent in IPv6 routing, whereas in IPv4 Anycast is handled via
provisioning in the network. Details are out of scope for this
document.)
o The contacted AMT Relay then returns its specific unicast IP
address (after which the Anycast address is no longer required).
Variations may exist as well.
o The AMT Gateway uses that unicast IP address to initiate a three-
way handshake with the AMT Relay.
o AMT Gateway provides "S,G" to the AMT Relay (embedded in AMT
protocol messages).
o AMT Relay receives the "S,G" information and uses the S,G to join
the appropriate multicast stream, if it has not already subscribed
to that stream.
o AMT Relay encapsulates the multicast stream into the tunnel
between the Relay and the Gateway, providing the requested content
to the EU.
IETF I-D Multicasting Applications Across Peering Points February 2014
Note: Further routing discussion on optimal method to find "best AMT
Relay/GW combination" and information exchange between AD's to be
provided.
4.3. Back Office Functions - Billing and Logging Guidelines 4.3. Back Office Functions - Billing and Logging Guidelines
4.4. Operations - Service Performance and Monitoring Guidelines 4.4. Operations - Service Performance and Monitoring Guidelines
4.5. Reliability Models/Service Assurance Guidelines 4.5. Reliability Models/Service Assurance Guidelines
4.6. Provisioning Guidelines 4.6. Provisioning Guidelines
In order to find right relay there is a need for a small/light In order to find right relay there is a need for a small/light
implementation of an AMT DNS in source network. implementation of an AMT DNS in source network.
4.7. Client Models 4.7. Client Models
4.8. Addressing Guidelines 4.8. Addressing Guidelines
IETF I-D Multicasting Applications Across Peering Points October 2013
5. Security Considerations 5. Security Considerations
(Include discussion on DRM, AAA, Network Security) (Include discussion on DRM, AAA, Network Security)
IETF I-D Multicasting Applications Across Peering Points February 2014
6. IANA Considerations 6. IANA Considerations
7. Conclusions 7. Conclusions
8. References 8. References
8.1. Normative References 8.1. Normative References
[RFC2784] D. Farinacci, T. Li, S. Hanks, D. Meyer, P. Traina, [RFC2784] D. Farinacci, T. Li, S. Hanks, D. Meyer, P. Traina,
"Generic Routing Encapsulation (GRE)", RFC 2784, March 2000 "Generic Routing Encapsulation (GRE)", RFC 2784, March 2000
skipping to change at page 15, line 35 skipping to change at page 20, line 31
[RFC4604] H. Holbrook, et al, "Using Internet Group Management [RFC4604] H. Holbrook, et al, "Using Internet Group Management
Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 3 (IGMPv3) and Multicast Listener Discovery
Protocol Version 2 (MLDv2) for Source Specific Multicast", RFC 4604, Protocol Version 2 (MLDv2) for Source Specific Multicast", RFC 4604,
August 2006 August 2006
[RFC4607] H. Holbrook, et al, "Source Specific Multicast", RFC 4607, [RFC4607] H. Holbrook, et al, "Source Specific Multicast", RFC 4607,
August 2006 August 2006
8.2. Informative References 8.2. Informative References
[INF_ATIS_10] "CDN Interconnection Use Cases and Requirements in a
Multi-Party Federation Environment", ATIS Standard A-0200010,
December 2012
9. Acknowledgments 9. Acknowledgments
IETF I-D Multicasting Applications Across Peering Points October 2013 IETF I-D Multicasting Applications Across Peering Points February 2014
Authors' Addresses Authors' Addresses
Percy S. Tarapore Percy S. Tarapore
AT&T AT&T
Phone: 1-732-420-4172 Phone: 1-732-420-4172
Email: tarapore@att.com Email: tarapore@att.com
Robert Sayko Robert Sayko
AT&T AT&T
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