The document shepherd is Kevin J. Ma. The responsible AD is Barry Leiba.
This document is a standards track submission that defines a
protocol by which an upstream CDN (uCDN) may query a downstream CDN
(dCDN), in a CDN Interconnection (CDNI), as to whether the dCDN
will accept a client redirected from the uCDN, and if so, to where in the
dCDN the client should be redirected. It is necessary for the recursive
redirection mode of CDNI. The WG believes that a standardized
method/protocol for determining if a dCDN is able and willing to
serve content for the uCDN is needed and will be useful.
2. Review and Consensus
The protocol is a straightforward RESTful API with JSON payloads
that contain key/value pairs, for extensibility. Currently known
parameters needed for DNS and HTTP redirection are defined. CDNI
supports two types of redirection: iterative redirection and
recursive redirection. This document specifically addresses
recursive redirection. Because iterative redirection is simpler
and more widely used today, the WG's focus was primarily on
iterative redirection; consequently, there was less discussion on
recursive redirection, but a smaller group of individuals within
the WG agreed that the parameters defined would be necessary and
Independent reviews were performed by Kevin J. Ma and Bert
Greevenbosch citing editorial and consistency issues; all comments
were addressed. A WG Chair review was performed by Francois Le
Faucheur citing editorial changes; all comments were addressed. An
appsdir early review was performed by Matt Miller, specifically
looking at the JSON encoding; all comments/nits were addressed. As
document shepherd, I performed a final review focusing on IANA
considerations and normative references, as well as citing
editorial and consistency issues; all comments were addressed.
A security concern was raised and discussed by the WG. The
protocol supports DNS redirection because CDNs use DNS redirection
today. Without DNSSEC, however, a client may not be able to
distinguish legitimate DNS redirection from a DNS-based attack.
The WG agreed that the concern should be documented (which it has
been), but that the existing functionality should move forward with
the understanding that DNSSEC is not a reasonable requirement for
all DNS redirection. The security aspects are being pursued in a
3. Intellectual Property
Each author has confirmed conformance with BCP 78/79.
There was one IPR disclosure from Juniper Networks. The disclosure
was announced on the list with only one response on the list
stating that the RAND terms seemed reasonable. The disclosure was
also discussed in the WG meeting at IETF94. The chairs agreed that
the RAND terms seemed reasonable and that there was no reason to
hold up the document. There were no objections from the WG.
4. Other Points
There are no downward references in the document.
The IANA Considerations registers two new CDNI Protocol Types. The
document shepherd and one of the editors are the two designated
expert reviewers for the CDNI Protocol Types registry and have
approved the addition.
The IANA Considerations also creates a new registry for error codes
for the protocol with sufficient guidelines provided to both IANA
and the designated expert reviewer.