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Bill St. Arnaud is a consultant and research engineer who works with clients around the world on a variety of subjects such as next generation Internet networks and developing practical solutions to reduce CO2 emissions such as free broadband and dynamic charging of eVehicles. He is an author of many papers and articles on these topics and is a frequent guest speaker. For more details on my research interests see

Thursday, March 29, 2012

Why R&E networks should be aware of the CDN Interconnect initiative (CDNI)

At the recent IETF meeting there has been considerable discussion about interconnection of Content Delivery Networks.
A lot of this is being driven unfortunately by the incumbent telco/cableco’s who never understood CDN in the first place, and now want to assert control over this critical new Internet architecture, much in the same way that they want to take control over open WiFi hot spots as part of an integration strategy with their 3G/4G networks.

R&E networks are the only independent organizations that have the knowledge and independence that can develop alternate strategies that don’t assume a “telco/cable uber alles” strategy. A good example is the Eduroam program which is now being used to seamlessly integrate WiFi with 3G/4G on networks like SURFnet, JANET, AARnet etc.

CDNI will be critical to a future anywhere, anyplace, anytime education and research strategy. It will also be critical to those R&E networks that operate transit or internet exchange points for community or anchor institution networks. Most R&E networks have come to realize that CDN and peering is critical to their core business functions. On some networks over 90% of the traffic is CDN and peering. It enables most R&E networks to become self sufficient and yet provide a much lower cost value proposition to their connected institutions, eliminating the dollars per Megabyte mindset of the incumbents. – BSA]

For more information on this topic please see:

A personal perspective on the evolving Internet and Research and Education Networks

OECD report: Internet Traffic Exchange Points

Content Distribution Network Interconnection (CDNI) Problem Statement

The volume of video and multimedia content delivered over the
Internet is rapidly increasing and expected to continue doing so in
the future. In the face of this growth, Content Delivery Networks
(CDNs) provide numerous benefits: reduced delivery cost for cacheable
content, improved quality of experience for End Users and increased
robustness of delivery. For these reasons CDNs are frequently used
for large-scale content delivery. As a result, existing CDN
Providers are scaling up their infrastructure and many Network
Service Providers (NSPs) are deploying their own CDNs.
It is generally desirable that a given content item can be delivered
to an End User regardless of that End User's location or attachment
network. However, a given CDN in charge of delivering a given
content may not have a footprint that expands close enough to the End
User's current location or attachment network, or may not have the
necessary resources, to realize the user experience and cost benefit
that a more distributed CDN infrastructure would allow. This is the
motivation for interconnecting standalone CDNs so that their
collective CDN footprint and resources can be leveraged for the end-
to-end delivery of content from Content Service Providers (CSPs) to
End Users. As an example, a CSP could contract with an
"authoritative" CDN Provider for the delivery of content and that
authoritative CDN Provider could contract with one or more downstream
CDN Provider(s) to distribute and deliver some or all of the content
on behalf of the authoritative CDN Provider. The formation and
details of any business relationships between a CSP and a CDN
Provider and between one CDN Provider and another CDN Provider are
out of scope of this document. However, no standards or open
specifications currently exist to facilitate such CDN
The goal of this document is to outline the problem area of CDN
interconnection. Section 2 discusses the use cases for CDN
interconnection. Section 3 presents the CDNI model and problem area
being considered by the IETF. Section 4 describes each CDNI
interface individually and highlights example candidate protocols
that could be considered for reuse or leveraging to implement the
CDNI interfaces. Appendix B.2 discusses the relevant work of other
standards organizations. Appendix B.4 describes the relationships
between the CDNI problem space and other relevant IETF Working

R&E Network and Green Internet Consultant.
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