Subject: [CDNi] Definitions inside PS and Framework draft

From: <[email-masked]>
Date: Mon, 28 Nov 2011 10:59:43 +0100

Colleagues,

As discussed during IETF#82, we are tidying up the terminology section of the use cases draft.

The use cases and the problem statement drafts propose slightly different definitions of some terms: 

Problem statement:

   Authoritative CDN: A CDN which has a direct relationship with a CSP

   for the distribution & delivery of that CSP's content.

   CDN Interconnection (CDNI): The set of interfaces over which two or
   more CDNs communicate with each other in order to achieve the
   delivery of content to User Agents by Surrogates in one CDN (the
   downstream CDN) on behalf of another CDN (the upstream CDN).

Use cases:

   Authoritative CDN (aCDN):   A CDN provider contracted by the CSP for delivery of content by its

   CDN or by its downstream CDNs.

  CDN Interconnection:

   Relationship between two CDNs that enables a CDN to provide content

   delivery services on behalf of another CDN.  It relies on a set of

   interfaces over which two CDNs communicate in order to achieve the

   delivery of content to end-users by one CDN (the downstream CDN) on

   behalf of another CDN (the upstream CDN).

I find these two definitions from the use cases draft clearer. Do you agree? 

Some relevant terms are defined only in the use cases draft. Could you please include them in the problem statement?

   Access CDN:

   A CDN that is directly connected to the end-user's access.  An Access

   CDN may have specific information about the end-user and the network,

   for instance, end-user's profile and access capabilities.

    Delivering CDN:

   The CDN that delivers the requested piece of content to the end-user.

   In particular, the delivering CDN can be an access CDN.

Some terms are not defined yet in the WG's drafts. Could you define them inside the framework draft?

   recursive request routing

   iterative request routing

Cordialement, with kind regards,

Gilles Bertrand
R&D, AudioVisual Delivery (AVD)
Content Network Architect
tél. +33 (0) 145 29 89 46 
[email-masked]

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From: Francois Le Faucheur <[email-masked]>
Date: Mon, 28 Nov 2011 16:28:49 +0100

Hi,

>    iterative request routing

Just FYI,

Below are the definitions that had been included in early versions of the "requirements" I-D (they are no longer in the latest versions of the Requirements I-D). 
Those may provide a good base for developing the definitions to be included in the Framework I-D.

"
   o  Recursive CDNI request routing: When an Upstream CDN elects to
      redirect a request towards a Downstream CDN, the Upstream CDN can
      query the Downstream CDN Request Routing system via the CDNI
      Request Routing protocol (or use information cached from earlier
      similar queries) to find out how the Downstream CDN wants the
      request to be redirected, which allows the Upstream CDN to factor
      in the Downstream CDN response when redirecting the user agent.
      This approach is referred to as "recursive" CDNI request routing.
      Note that the Downstream CDN may elect to have the request
      redirected directly to a Surrogate inside the Downstream CDN, to
      the Request-Routing System of the Downstream CDN, to another CDN,
      or to any other system that the Downstream CDN sees as fit for
      handling the redirected request.

   o  Iterative CDNI Request Routing: When an Upstream CDN elects to
      redirect a request towards a Downstream CDN, the Upstream CDN can
      base its redirection purely on a local decision (and without
      attempting to take into account how the Downstream CDN may in turn
      redirect the user agent).  In that case, the Upstream CDN
      redirects the request to the request routing system in the
      Downstream CDN, which in turn will decide how to redirect that
      request: this approach is referred to as "iterative" CDNI request
      routing.
"

Cheers

Francois

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From: Bruce Davie <[email-masked]>
Date: Tue, 29 Nov 2011 21:32:35 -0500

>    iterative request routing
I think you will find that these are defined in draft-davie-cdni-framework-01.txt, with text lifted from an earlier version of the requirements draft.

Bruce

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From: <[email-masked]>
Date: Wed, 30 Nov 2011 09:40:14 +0100

My mistake. They are indeed defined, I must have checked in the former version instead of version 01.

Gilles

De : Bruce Davie [mailto:[email-masked]] 
Envoyé : mercredi 30 novembre 2011 03:33
À : BERTRAND Gilles RD-CORE-ISS
Cc : [email-masked]
Objet : Re: Definitions inside PS and Framework draft

 

Bruce