draft-seedorf-cdni-request-routing-alto-05.txt   draft-seedorf-cdni-request-routing-alto-06.txt 
CDNI J. Seedorf CDNI J. Seedorf
Internet-Draft NEC Internet-Draft NEC
Intended status: Informational Y. Yang Intended status: Informational Y. Yang
Expires: April 24, 2014 Yale Expires: August 18, 2014 Yale
October 21, 2013 February 14, 2014
CDNI Footprint and Capabilities Advertisement using ALTO CDNI Footprint and Capabilities Advertisement using ALTO
draft-seedorf-cdni-request-routing-alto-05 draft-seedorf-cdni-request-routing-alto-06
Abstract Abstract
Network Service Providers (NSPs) are currently considering to deploy Network Service Providers (NSPs) are currently considering to deploy
Content Delivery Networks (CDNs) within their networks. As a Content Delivery Networks (CDNs) within their networks. As a
consequence of this development, there is a need for interconnecting consequence of this development, there is a need for interconnecting
these local CDNs. The necessary interfaces for inter-connecting CDNs these local CDNs. The necessary interfaces for inter-connecting CDNs
are currently being defined in the Content Delivery Networks are currently being defined in the Content Delivery Networks
Interconnection (CDNI) WG. This document focuses on the CDNI Interconnection (CDNI) WG. This document focuses on the CDNI
Footprint & Capabilities Advertisement interface (FCI). Footprint & Capabilities Advertisement interface (FCI).
skipping to change at page 1, line 45 skipping to change at page 1, line 45
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 24, 2014. This Internet-Draft will expire on August 18, 2014.
Copyright Notice Copyright Notice
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Copyright (c) 2014 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. ALTO within CDNI Request Routing . . . . . . . . . . . . . . 3 2. ALTO within CDNI Request Routing . . . . . . . . . . . . . . 3
3. Assumptions and High-Level Design Considerations . . . . . . 4 3. Assumptions and High-Level Design Considerations . . . . . . 4
3.1. General Assumptions and Consideration . . . . . . . . . . 4 3.1. General Assumptions and Consideration . . . . . . . . . . 5
3.2. Semantics for Footprint/Capabilities Advertisment . . . . 5 3.2. Semantics for Footprint/Capabilities Advertisment . . . . 5
4. Selection of a Downstream CDN with ALTO . . . . . . . . . . . 7 4. Selection of a Downstream CDN with ALTO . . . . . . . . . . . 7
4.1. Footprint and Capabilities Advertisement using ALTO 4.1. Footprint and Capabilities Advertisement using ALTO
Network Map and PID Properties . . . . . . . . . . . . . 7 Network Map and PID Properties . . . . . . . . . . . . . 7
4.2. Conveying additional information with ALTO Cost Maps . . 8 4.2. Conveying additional information with ALTO Cost Maps . . 9
4.3. Example of Selecting a Downstream CDN based on ALTO Maps 9 4.3. Example of Selecting a Downstream CDN based on ALTO Maps 9
4.4. Advantages of using ALTO . . . . . . . . . . . . . . . . 10 4.4. Advantages of using ALTO as the CDNI FCI protocol . . . . 10
5. Useful ALTO extensions for CDNI Request Routing . . . . . . . 10 5. Concrete Examples with ALTO Maps . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 5.1. Example ALTO Network Map . . . . . . . . . . . . . . . . 11
7. Summary and Outlook . . . . . . . . . . . . . . . . . . . . . 12 5.2. Example ALTO PID Property . . . . . . . . . . . . . . . . 12
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 6. Useful ALTO extensions for CDNI Request Routing . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 13 8. Summary and Outlook . . . . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 13 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
Many Network Service Providers (NSPs) are currently considering or Many Network Service Providers (NSPs) are currently considering or
have already started to deploy Content Delivery Networks (CDNs) have already started to deploy Content Delivery Networks (CDNs)
within their networks. As a consequence of this development, there within their networks. As a consequence of this development, there
is a need for interconnecting these local CDNs. Content Delivery is a need for interconnecting these local CDNs. Content Delivery
Networks Interconnection (CDNI) has the goal of standardizing Networks Interconnection (CDNI) has the goal of standardizing
protocols to enable such interconnection of CDNs [RFC6707]. protocols to enable such interconnection of CDNs [RFC6707].
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* Capabilities related to CDNI Metadata (e.g., authorization * Capabilities related to CDNI Metadata (e.g., authorization
algorithms or support for proprietary vendor metadata) algorithms or support for proprietary vendor metadata)
4. Selection of a Downstream CDN with ALTO 4. Selection of a Downstream CDN with ALTO
Under the considerations stated in Section 3, ALTO can help the Under the considerations stated in Section 3, ALTO can help the
upstream CDN provider to select a proper downstream CDN provider for upstream CDN provider to select a proper downstream CDN provider for
a given end user request as follows: Each downstream CDN provider a given end user request as follows: Each downstream CDN provider
hosts an ALTO server which provides ALTO information (i.e. ALTO hosts an ALTO server which provides ALTO information (i.e. ALTO
network maps and ALTO cost maps [I-D.ietf-alto-protocol]) to an ALTO network maps and potentially additonally ALTO cost maps
client at the upstream CDN provider. Network maps provided by each [I-D.ietf-alto-protocol]) to an ALTO client at the upstream CDN
of several candidate downstream CDNs can provide information to the provider. Network maps provided by each of several candidate
upstream CDN provider about each dCDN's "coverage/reachability" as downstream CDNs can provide information to the upstream CDN provider
well as capabilities. about each dCDN's "coverage/reachability" as well as capabilities.
4.1. Footprint and Capabilities Advertisement using ALTO Network Map 4.1. Footprint and Capabilities Advertisement using ALTO Network Map
and PID Properties and PID Properties
Conceptually, the foorprint and capabilities interface of a dCDN is Conceptually, the footprint and capabilities interface of a dCDN is
easy to specify: It is a function that given an endhost, returns if easy to specify: It is a function that given an endhost, returns if
the dCDN is willing to serve the endhost, and the capabilities the dCDN is willing to serve the endhost, and the capabilities
available to that endhost (e.g., "delivery-protocol": available to that endhost (e.g., "delivery-protocol":
["HTTP","RMTP"], "acquisition-protocol": ["HTTP"], "redirection- ["HTTP","RMTP"], "acquisition-protocol": ["HTTP"], "redirection-
mode": ["HTTP-redirect"], "loggin-mechanism": ["TBD"], and "meta- mode": ["HTTP-redirect"], "loggin-mechanism": ["TBD"], and "meta-
capabilities": [""]). capabilities": [""]).
Specifiying the preceding for each endhost can be redundant, and one Specifiying the preceding for each endhost can be redundant, and one
may use PIDs defined in ALTO. Specifically, an ALTO network map may use PIDs defined in ALTO. Specifically, an ALTO network map
contains a "set of Network Location groupings" contains a "set of Network Location groupings"
[I-D.ietf-alto-protocol]. The groupings are defined in the form of [I-D.ietf-alto-protocol]. The groupings are defined in the form of
so-called "PIDs". A PID is an identifier to group network location so-called "PIDs". A PID is an identifier to group network location
endpoints, e.g. IP-addresses in the form of prefixes (see section 4 endpoints, e.g. IP-addresses in the form of prefixes (see section 4
in [I-D.ietf-alto-protocol] for details). in [I-D.ietf-alto-protocol] for details).
Applying the basic idea of ALTO PIDs to the preceding, abstract Applying the basic idea of ALTO PIDs to the preceding, abstract
mapping specification, by aggregating endhosts with the same mapping specification, by aggregating endhosts with the same
capabilities in the same PID, we obtain CDNi FCI using ALTO Network capabilities in the same PID, we obtain CDNi FCI using ALTO Network
Maps as simply (1) a Network Map which defines a set of PIDs, and (2) Maps as simply (1) a Network Map which defines a set of PIDs, and (2)
a PID Property Map [draft-roome-alto-pid-properties ] that defines a PID Property Map [draft-roome-alto-pid-properties] that defines the
the properties of each PID, where the properties define the properties of each PID, where the properties define the capabilities.
capabilities.
With the preceding Network Map and PID Property Map, the upstream CDN With the preceding Network Map and PID Property Map, the upstream CDN
provider can easily match a given end user request with the footprint provider can easily match a given end user request with the footprint
and capabilities of the downstream CDN providers. Whenever the and capabilities of the downstream CDN providers. Whenever the
footprint and/or capabilities of a dCDN change, the ALTO server of footprint and/or capabilities of a dCDN change, the ALTO server of
the dCDN changes its data, and the uCDN can obtain the update through the dCDN changes its data, and the uCDN can obtain the update through
ALTO incremental updates. Future extensions to ALTO to add ALTO incremental updates. Future extensions to ALTO to add
notifications can be integrated when they become available. notifications can be integrated when they become available.
In particular, this document does not define how a dCDN aggregates In particular, this document does not define how a dCDN aggregates
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In this document, we define the following PID properties, which each In this document, we define the following PID properties, which each
must be a JSON array, to convey all mandatory capabilities (see must be a JSON array, to convey all mandatory capabilities (see
Section 3.2): Section 3.2):
o delivery-protocol o delivery-protocol
o acquisition-protocol o acquisition-protocol
o redirection-mode o redirection-mode
o loggin-mechanism o logging-mechanism
o meta-capabilities o meta-capabilities
To complement the preceding capabilities mapping, we require that an To complement the preceding capabilities mapping, we require that an
uCDN has access to ALTO Network Map(s) that can map from an endhost uCDN has access to ALTO Network Map(s) that can map from an endhost
to Country Code and AS Number. Such mapping may or may not be to Country Code and AS Number. Such mapping may or may not be
specific to CDNI but can be a general mapping. Specifically, the specific to CDNI but can be a general mapping. Specifically, the
uCDN should have access to ALTO Network Map(s) with Properties uCDN should have access to ALTO Network Map(s) which Properties
include: include:
o country-code o country-code
o asn o asn
4.2. Conveying additional information with ALTO Cost Maps 4.2. Conveying additional information with ALTO Cost Maps
An ALTO cost map contains costs between defined groupings of a An ALTO cost map contains costs between defined groupings of a
corresponding network map (i.e. costs between PIDs): "An ALTO Cost corresponding network map (i.e. costs between PIDs): "An ALTO Cost
Map defines Path Costs pairwise amongst sets of source and Map defines Path Costs pairwise amongst sets of source and
destination Network Locations" [I-D.ietf-alto-protocol]. This destination Network Locations" [I-D.ietf-alto-protocol]. This
concept enables the provider of a cost map to express (and quantify) concept enables the provider of a cost map to express (and quantify)
preferences of a destination network location with respect to a given preferences of a destination network location with respect to a given
source network location. source network location.
In the context of CDNI, the ALTO cost map concept is an extensive In the context of CDNI, the ALTO cost map concept is an extensive
tool to convey additional information about the footprint or tool to convey additional information about the footprint or
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to m dCDN request router PIDs. Semantically, a source PID in a CDNI to m dCDN request router PIDs. Semantically, a source PID in a CDNI
ALTO cost map is thus the end user location, whereas a destination ALTO cost map is thus the end user location, whereas a destination
PID is a (group of) request router(s) to which the uCDN redirects the PID is a (group of) request router(s) to which the uCDN redirects the
end user request. Note that this perspective is driven by the CDNI end user request. Note that this perspective is driven by the CDNI
request routing. An alternative way - seen from the perspective of request routing. An alternative way - seen from the perspective of
content retrieval - would be to have a m-to-N cost map where the content retrieval - would be to have a m-to-N cost map where the
source is always the dCDN and the destination is the end user (with source is always the dCDN and the destination is the end user (with
the semantic "if the source dCDN would deliver content to an end user the semantic "if the source dCDN would deliver content to an end user
in the destination PID, the costs would be the following). With in the destination PID, the costs would be the following). With
explicit destination PIDs reflecting different entries to the same explicit destination PIDs reflecting different entries to the same
dCDN, the dCDN can convey shortcut or differentiaed quality of dCDN, the dCDN can convey shortcut or differentiated quality of
services. services.
4.3. Example of Selecting a Downstream CDN based on ALTO Maps 4.3. Example of Selecting a Downstream CDN based on ALTO Maps
In the following, we will outline an example of dCDN selection by a In the following, we will outline an example of dCDN selection by a
uCDN based on ALTO maps provided by dCDNs. Consider the following uCDN based on ALTO maps provided by dCDNs. Consider the following
example: An upstream CDN (uCDN) has agreed on CDN interconnection example: An upstream CDN (uCDN) has agreed on CDN interconnection
with several downstream CDNs (dCDN-a, dCDN-b, and dCDN-c). Each of with several downstream CDNs (dCDN-a, dCDN-b, and dCDN-c). Each of
these downstream CDNs runs an ALTO server to provide aforementioned these downstream CDNs runs an ALTO server to provide aforementioned
ALTO information. Whenever the upstream CDN receives a request from ALTO information. Whenever the upstream CDN receives a request from
an end user and has determined that this request is best served by an an end user and has determined that this request is best served by an
interconnected dCDN, the uCDN uses ALTO maps to make a redirection interconnected dCDN, the uCDN uses ALTO maps to make a redirection
decision. For a given request, assume that only the ALTO network decision. For a given request, assume that only the ALTO network
maps provided by dCDN-a and dCDN-c include the endhost. The uCDN maps provided by dCDN-a and dCDN-c include the endhost. The uCDN
first looks up the PIDs of the endhost in the two network maps from first looks up the PIDs of the endhost in the two network maps from
the two dCDNs, then search the PID properties to find out the the two dCDNs, and then searches the PID properties to find out the
capabilities of each dCDN for the endhost. If only one dCDN supports capabilities of each dCDN for the endhost. If only one dCDN supports
the required capabilities, then the uCDN chooses the dCDN. the required capabilities, then the uCDN chooses the dCDN.
Otherwise, if Cost Maps are available to provide additional server Otherwise, the UCDN uses additional server selection information
selection information (e.g., a Cost Map defining latency), the uCDN (i.e. information obtained outside the CDNI FCI interface such as
picks the dCDN with better cost performance. business agreements) at its own discretion in order to pick a dCDN
among the ones that provide the necessary capabilities for the given
end host request.
4.4. Advantages of using ALTO 4.4. Advantages of using ALTO as the CDNI FCI protocol
The following reasons make ALTO a suitable candidate protocol for The following reasons make ALTO a suitable candidate protocol for
downstream CDN selection as part of CDNI request routing and in downstream CDN selection as part of CDNI request routing and in
particular for a FCI protocol: particular for an FCI protocol:
o CDN request routing is done at the application layer. ALTO is a o CDN request routing is done at the application layer. ALTO is a
protocol specifically designed to improve application layer protocol specifically designed to improve application layer
traffic (and application layer connections among hosts on the traffic (and application layer connections among hosts on the
Internet) by providing additonal information to applications that Internet) by providing additonal information to applications that
these applications could not easily retrieve themselves. For these applications could not easily retrieve themselves. For
CDNI, this is exactly the case: a uCDN wants to improve CDNI, this is exactly the case: a uCDN wants to improve
application layer CDN request routing by using dedicated application layer CDN request routing by using dedicated
information (provided by a dCDN) that the uCDN could not easily information (provided by a dCDN) that the uCDN could not easily
obtain otherwise. obtain otherwise.
o The semantics of an ALTO network are an exact match for the needed o The semantics of an ALTO network map are an exact match for the
information to convey a footprint by a downstream CDN, in needed information to convey a footprint by a downstream CDN, in
particular if such a footprint is being expressed by IP-prefix particular if such a footprint is being expressed by IP-prefix
ranges. ranges.
o ALTO cost maps are suitable to express various types of numeric o The PID concept allows for clean separation between footprint and
values and can hence be used by an upstream CDN to obtain metrics capabilities: The PID gives a name to a footprint and a dCDN can
for capabilities associated with a given dCDN for a given then easily change separately either a) the Properties for a given
foorprint. Further, an ALTO cost map could also convey relevant footprint, or b) the Composition of a given footprint.
network topology information other than simply routing hops or
reachability. This facilitiates advanced and more sophisticated
selection of a downstream CDN based on various metrics by the
upstream CDN and increases flexibility to cover different use
cases and business models for CDN interconnection.
o Flexible granularity: The concept of the PID and ALTO network/cost o Flexible granularity: The concept of the PID and ALTO network/cost
maps allows for different degrees of granularity. This enables a maps allows for different degrees of granularity. This enables a
dCDN to differentiate the delivery quality for serving an end user dCDN to differentiate the delivery quality for serving an end user
request on a fine granularity depending on the end user location request on a fine granularity depending on the end user location
(and not only express delivery quality e.g. on an AS-level). It (and not only express delivery quality e.g. on an AS-level). It
remains at the discretion of each dCDN how fine-granular the ALTO remains at the discretion of each dCDN how fine-granular the ALTO
network and cost maps are that it publishes. network and cost maps are that it publishes.
o ALTO maps can be signed and hence provide inherent integrity o Security: ALTO maps can be signed and hence provide inherent
protection (see Section 6) integrity protection (see Section 7)
o RESTful-Design: The ALTO protocol has undergone extensive
revisions in order to provide a RESTful design regarding the
client-server interaction specified by the protocol. A CDNI FCI
interface based on ALTO would inherit this RESTful design.
o Error-handling: The ALTO protocol has undergone extensive
revisions in order to provide sophisticated error-handling,
inparticular regarding unexpected cases. A CDNI FCI interface
based on ALTO would inherit this thought-through and mature error-
handling.
o Endpoint Property Service: The ALTO Endpoint Property Service (see
[I-D.ietf-alto-protocol] for details) would allow an upstream CDN
to query capabilities for an individual endpoint (without querying
the whole map).
o Filtered network map: The ALTO Map Filtering Service (see
[I-D.ietf-alto-protocol] for details) would allow a uCDN to query
only for parts of an ALTO map.
5. Concrete Examples with ALTO Maps
The following examples show concrete ALTO maps and how CDNI FCI would
be facilitated with these as described in the previous Section.
5.1. Example ALTO Network Map
The following network map would convey to a uCDN that the given dCDN
(which would provide the map) has three footprints called ''south-
france'', ''germany'', and ''rest'', and provide the corresponding
IPv4 address ranges for these footprints. The entry ''cdni-fruit'' :
[''orange''] in the ''south-france'' footprint is an example of how
new endpoint types (e.g. proprietary ones that are defined outside
the CDNI FCI among certain CDNs) could be used in an ALTO network
map.
GET /networkmap/eu HTTP/1.1
Host: cdni.example.com
Accept: application/alto-networkmap+json,application/alto-error+json
HTTP/1.1 200 OK
Content-Length: TBA
Content-Type: application/alto-networkmap+json
{
"meta" : {
"vtag": [
{"resource-id": "my-eu-netmap",
"tag": "1266506139"
}
]
},
"network-map" : {
"south-france" : {
"ipv4" : [ "192.0.2.0/24", "198.51.100.0/25" ], "cdni-fruit" : ["orange"]
},
"germany" : {
"ipv4" : [ "192.0.3.0/24"]
},
"rest" : { "ipv4": [0.0.0.0/0], "ipv6"; [::/0] }
}
}
5.2. Example ALTO PID Property
The following PID properties would correspond to the footprints from
the network map shown in the previous subsection and convey to the
uCDN that the capabilities for all endpoints in the footprint
''south-france'' are ["HTTP"], and that the capabilities for all
endpoints in the footprint ''germany'' are ["HTTP", "HTTPS"].
HTTP/1.1 200 OK
Content-Length: TBA
Content-Type: application/alto-pidprop+json
{
"meta" : {
"dependent-vtags" : [
{"resource-id": "my-eu-netmap",
"tag": "1266506139"
}
]
},
"properties": {
"pid:south-france" : { "delivery-protocol": ["HTTP"], ... },
"pid:germany" : { "delivery-protocol": ["HTTP", "HTTPS"], ... },
"pid:rest" : {}
}
}
6. Useful ALTO extensions for CDNI Request Routing
5. Useful ALTO extensions for CDNI Request Routing
It is envisioned that yet-to-be-defined ALTO extensions will be It is envisioned that yet-to-be-defined ALTO extensions will be
standardized that make the ALTO protocol more suitable and useful for standardized that make the ALTO protocol more suitable and useful for
applications other than the originally considered P2P use case applications other than the originally considered P2P use case
[I-D.marocco-alto-next]. Some of these extensions to the ALTO [I-D.marocco-alto-next]. Some of these extensions to the ALTO
protocol would be useful for ALTO to be used as a protocol within protocol would be useful for ALTO to be used as a protocol within
CDNI request routing, and in particular within the "Footprint and CDNI request routing, and in particular within the "Footprint and
Capabilities Advertisment" part of the CDNI request routing Capabilities Advertisment" part of the CDNI request routing
interface. interface.
The following proposed extensions to ALTO would be beneficial to The following proposed extensions to ALTO would be beneficial to
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useful information for an upstream CDN for optimized dowmstream useful information for an upstream CDN for optimized dowmstream
CDN selection. For instance, if a uCDN receives a streaming CDN selection. For instance, if a uCDN receives a streaming
request for content with a certain bitrate, it needs to know if it request for content with a certain bitrate, it needs to know if it
is likely that a dCDN can fulfill such stringent application-level is likely that a dCDN can fulfill such stringent application-level
requirements (i.e. can be expected to have enough consistent requirements (i.e. can be expected to have enough consistent
bandwidth) before it redirects the request. In general, if ALTO bandwidth) before it redirects the request. In general, if ALTO
could convey such information via new endpoint properties, it could convey such information via new endpoint properties, it
would enable more sophisticated means for downstream CDN selection would enable more sophisticated means for downstream CDN selection
with ALTO. with ALTO.
6. Security Considerations 7. Security Considerations
One important security consideration is the proper authentication of One important security consideration is the proper authentication of
advertisement information provided by a downstream CDN. The ALTO advertisement information provided by a downstream CDN. The ALTO
protocol provides a specification for a signature of ALTO maps (see protocol provides a specification for a signature of ALTO maps (see
8.2.2. of [I-D.ietf-alto-protocol]. ALTO thus provides a proper 8.2.2. of [I-D.ietf-alto-protocol]. ALTO thus provides a proper
means for protecting the integrity of footprint advertisment means for protecting the integrity of footprint advertisment
information. information.
More Security Considerations will be discussed in a future version of More Security Considerations will be discussed in a future version of
this document. this document.
7. Summary and Outlook 8. Summary and Outlook
This document presented conrete examples of how ALTO can be used This document presented conrete examples of how ALTO can be used
within the downstream CDN selection of CDNI Request Routing. within the downstream CDN selection of CDNI Request Routing.
Further, the document provides arguments why ALTO is a meaningful Further, the document provides arguments why ALTO is a meaningful
protocol in this context. Essentially, ALTO network and cost maps protocol in this context. Essentially, ALTO network and cost maps
are a means to provide detailed and various types of information to are a means to provide detailed and various types of information to
an upstream CDN, in order to facilitate well-considered downstream an upstream CDN, in order to facilitate well-considered downstream
CDN selection. CDN selection.
The intention of this document is to find consensus in the CDNI WG The intention of this document is to find consensus in the CDNI WG
that ALTO is a useful protocol for CDNI request routing, and that that ALTO is a useful protocol for CDNI request routing, and that
ALTO has many benefits for proper selection of a downstream CDN. The ALTO has many benefits for proper selection of a downstream CDN. The
overall objective is to form agreement on how ALTO should be used overall objective is to form agreement on how ALTO should be used
within the CDNI request routing protocol. It is the intention to within the CDNI request routing protocol. It is the intention to
capture the outcome of such continuing discussions in future versions capture the outcome of such continuing discussions in future versions
of this document. of this document.
8. Acknowledgements 9. Acknowledgements
Jan Seedorf is partially supported by the CHANGE project (CHANGE: Jan Seedorf is partially supported by the CHANGE project (CHANGE:
Enabling Innovation in the Internet Architecture through Flexible Enabling Innovation in the Internet Architecture through Flexible
Flow-Processing Extensions, http://www.change-project.eu/), a Flow-Processing Extensions, http://www.change-project.eu/), a
research project supported by the European Commission under its 7th research project supported by the European Commission under its 7th
Framework Program (contract no. 257422). The views and conclusions Framework Program (contract no. 257422). The views and conclusions
contained herein are those of the authors and should not be contained herein are those of the authors and should not be
interpreted as necessarily representing the official policies or interpreted as necessarily representing the official policies or
endorsements, either expressed or implied, of the CHANGE project or endorsements, either expressed or implied, of the CHANGE project or
the European Commission. the European Commission.
Jan Seedorf has been partially supported by the COAST project Jan Seedorf has been partially supported by the COAST project
(COntent Aware Searching, retrieval and sTreaming, http://www.coast- (COntent Aware Searching, retrieval and sTreaming, http://www.coast-
fp7.eu), a research project supported by the European Commission fp7.eu), a research project supported by the European Commission
under its 7th Framework Program (contract no. 248036). The views under its 7th Framework Program (contract no. 248036). The views
and conclusions contained herein are those of the authors and should and conclusions contained herein are those of the authors and should
not be interpreted as necessarily representing the official policies not be interpreted as necessarily representing the official policies
or endorsements, either expressed or implied, of the COAST project or or endorsements, either expressed or implied, of the COAST project or
the European Commission. the European Commission.
9. References 10. References
9.1. Normative References 10.1. Normative References
[RFC5693] Seedorf, J. and E. Burger, "Application-Layer Traffic [RFC5693] Seedorf, J. and E. Burger, "Application-Layer Traffic
Optimization (ALTO) Problem Statement", RFC 5693, October Optimization (ALTO) Problem Statement", RFC 5693, October
2009. 2009.
[RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content [RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
Distribution Network Interconnection (CDNI) Problem Distribution Network Interconnection (CDNI) Problem
Statement", RFC 6707, September 2012. Statement", RFC 6707, September 2012.
[RFC6770] Bertrand, G., Stephan, E., Burbridge, T., Eardley, P., Ma, [RFC6770] Bertrand, G., Stephan, E., Burbridge, T., Eardley, P., Ma,
K., and G. Watson, "Use Cases for Content Delivery Network K., and G. Watson, "Use Cases for Content Delivery Network
Interconnection", RFC 6770, November 2012. Interconnection", RFC 6770, November 2012.
9.2. Informative References 10.2. Informative References
[I-D.peterson-CDNI-strawman] [I-D.peterson-CDNI-strawman]
Peterson, L. and J. Hartman, "Content Distribution Network Peterson, L. and J. Hartman, "Content Distribution Network
Interconnection (CDNI) Problem Statement", draft-peterson- Interconnection (CDNI) Problem Statement", draft-peterson-
CDNI-strawman-01 (work in progress), May 2011. CDNI-strawman-01 (work in progress), May 2011.
[I-D.ietf-cdni-problem-statement] [I-D.ietf-cdni-problem-statement]
Niven-Jenkins, B., Faucheur, F., and N. Bitar, "Content Niven-Jenkins, B., Faucheur, F., and N. Bitar, "Content
Distribution Network Interconnection (CDNI) Problem Distribution Network Interconnection (CDNI) Problem
Statement", draft-ietf-cdni-problem-statement-08 (work in Statement", draft-ietf-cdni-problem-statement-08 (work in
progress), June 2012. progress), June 2012.
[I-D.marocco-alto-next] [I-D.marocco-alto-next]
Marocco, E. and V. Gurbani, "Extending the Application- Marocco, E. and V. Gurbani, "Extending the Application-
Layer Traffic Optimization (ALTO) Protocol", draft- Layer Traffic Optimization (ALTO) Protocol", draft-
marocco-alto-next-00 (work in progress), January 2012. marocco-alto-next-00 (work in progress), January 2012.
[I-D.ietf-alto-protocol] [I-D.ietf-alto-protocol]
Alimi, R., Penno, R., and Y. Yang, "ALTO Protocol", draft- Alimi, R., Penno, R., and Y. Yang, "ALTO Protocol", draft-
ietf-alto-protocol-20 (work in progress), October 2013. ietf-alto-protocol-25 (work in progress), January 2014.
[I-D.ietf-cdni-requirements] [I-D.ietf-cdni-requirements]
Leung, K. and Y. Lee, "Content Distribution Network Leung, K. and Y. Lee, "Content Distribution Network
Interconnection (CDNI) Requirements", draft-ietf-cdni- Interconnection (CDNI) Requirements", draft-ietf-cdni-
requirements-11 (work in progress), October 2013. requirements-17 (work in progress), January 2014.
[I-D.ietf-cdni-use-cases] [I-D.ietf-cdni-use-cases]
Bertrand, G., Emile, S., Burbridge, T., Eardley, P., Ma, Bertrand, G., Emile, S., Burbridge, T., Eardley, P., Ma,
K., and G. Watson, "Use Cases for Content Delivery Network K., and G. Watson, "Use Cases for Content Delivery Network
Interconnection", draft-ietf-cdni-use-cases-10 (work in Interconnection", draft-ietf-cdni-use-cases-10 (work in
progress), August 2012. progress), August 2012.
[I-D.marocco-alto-ws] [I-D.marocco-alto-ws]
Marocco, E. and J. Seedorf, "WebSocket-based server-to- Marocco, E. and J. Seedorf, "WebSocket-based server-to-
client notifications for the Application-Layer Traffic client notifications for the Application-Layer Traffic
Optimization (ALTO) Protocol", draft-marocco-alto-ws-01 Optimization (ALTO) Protocol", draft-marocco-alto-ws-02
(work in progress), July 2012. (work in progress), February 2014.
[I-D.schwan-alto-incr-updates] [I-D.schwan-alto-incr-updates]
Schwan, N. and B. Roome, "ALTO Incremental Updates", Schwan, N. and B. Roome, "ALTO Incremental Updates",
draft-schwan-alto-incr-updates-02 (work in progress), July draft-schwan-alto-incr-updates-02 (work in progress), July
2012. 2012.
[I-D.jenkins-alto-cdn-use-cases] [I-D.jenkins-alto-cdn-use-cases]
Niven-Jenkins, B., Watson, G., Bitar, N., Medved, J., and Niven-Jenkins, B., Watson, G., Bitar, N., Medved, J., and
S. Previdi, "Use Cases for ALTO within CDNs", draft- S. Previdi, "Use Cases for ALTO within CDNs", draft-
jenkins-alto-cdn-use-cases-03 (work in progress), June jenkins-alto-cdn-use-cases-03 (work in progress), June
2012. 2012.
[I-D.seedorf-alto-for-cdni] [I-D.seedorf-alto-for-cdni]
Seedorf, J., "ALTO for CDNi Request Routing", draft- Seedorf, J., "ALTO for CDNi Request Routing", draft-
seedorf-alto-for-cdni-00 (work in progress), October 2011. seedorf-alto-for-cdni-00 (work in progress), October 2011.
[I-D.ietf-cdni-framework] [I-D.ietf-cdni-framework]
Peterson, L. and B. Davie, "Framework for CDN Peterson, L., Davie, B., and R. Brandenburg, "Framework
Interconnection", draft-ietf-cdni-framework-06 (work in for CDN Interconnection", draft-ietf-cdni-framework-09
progress), October 2013. (work in progress), January 2014.
[I-D.liu-cdni-cost] [I-D.liu-cdni-cost]
Liu, H., "A Cost Perspective on Using Multiple CDNs", Liu, H., "A Cost Perspective on Using Multiple CDNs",
draft-liu-cdni-cost-00 (work in progress), October 2011. draft-liu-cdni-cost-00 (work in progress), October 2011.
[I-D.spp-cdni-rr-foot-cap-semantics] [I-D.spp-cdni-rr-foot-cap-semantics]
Seedorf, J., Peterson, J., Previdi, S., Brandenburg, R., Seedorf, J., Peterson, J., Previdi, S., Brandenburg, R.,
and K. Ma, "CDNI Request Routing: Footprint and and K. Ma, "CDNI Request Routing: Footprint and
Capabilities Semantics", draft-spp-cdni-rr-foot-cap- Capabilities Semantics", draft-spp-cdni-rr-foot-cap-
semantics-04 (work in progress), February 2013. semantics-04 (work in progress), February 2013.
 End of changes. 32 change blocks. 
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