Comments to Problem Statement Document 1f

Hi all,
Here are some comments to the current version
http://www.w3.org/2005/MWI/BPWG/Group/TaskForces/CT/editors-drafts/Probl
emStatement/071008

Re "4. Origin servers must be able to selectively enable or disable
features of transforming proxies.":
[bryan] I would say here "must be able to request selective enabling or
disabling...". It may not be the policy of the CT proxy provider to
allow sites to control the proxy's behavior. For example, a CT proxy
that removes "bad words" etc as a "Parental Control" feature may not
allow content providers to disable this function. Another example is the
insertion of content, e.g. footers or ads, which the CT proxy may not
allow to be disabled per the service agreement betweem the CT proxy
provider and the user. I agree that selective control will be useful,
but compliance by the CT proxy cannot be mandated in all cases.

Re "5. Origin servers and proxies must be able to identify the actual
identity of components of the delivery context, including (other)
proxies and browsers.":
[bryan] For proxies, it's not the "identity" that is important but the
configuration of the proxy for the current delivery context. One proxy
can provide different CT service for different users and delivery
context attributes (e.g. mobile access network in use). What the
downstream proxies and origin servers (may) need to know is what the
proxy is configured to do in the current context.

Re "6. Origin servers must be able to prohibit any kind of
transformation of its content.":
[bryan] This should be covered by [4] above, and is subject to the same
limitations per CT proxy provider policy. 

Re "2.2.2.2 Non Web Applications":
[bryan] The same comment as for [6] applies, otherwise an alternate
requirement is proposed: "Transforming proxies must be configurable to
disable transformation for non-web applications, e.g. if transformation
would serve no useful purpose or break non-web applications.". The key
difference here is that the control of the transformation disabling is
in the configuration of the CT proxy, and thus does not require
transformation-control enhancements to arbitrary non-web application
protocols.

Re "2.2.2.3 Legal, Moral and Commercial Issues":
[bryan] The same comment as for [6] applies.

Re "11. It must be possible for origin servers selectively to indicate
that content of various types must not be removed, replaced or inserted
by transforming proxies."
[bryan] This should be covered by [4] above, as a detailed feature of
transforming proxies.

One additional requirement that could be added as a compromise on the
policy control issues, is that "Transforming proxies must return an
error response to the user agent if the transforming proxy cannot comply
with an origin server request to enable or disable a transformation
proxy feature".

Best regards,
Bryan Sullivan

Received on Thursday, 11 October 2007 14:24:47 UTC