Re: Verizon guidelines

Jo, the problem remains that CTG is currently being used to justify 
abusive installations. This is the reality.
Anyway, I now believe that there is limited value in discussing this 
further, since the core of the discussion has been reached.

Manifesto Signers: the responsibility of preserving mobile content must 
be 100% of operators who deploy transcoders.

CTG WG: If a content owner does not want its content reformatted, they 
need to actively change their application and use Vary and 
Cache-Control:no-transform headers.

Do we agree on these simple statements?


Jo Rabin wrote:
> From this thread:
> With CTG in its current form, it works like:
> Novarra: Verizon is compliant with CTG.
> Tom Hume: No, they are not.
> Novarra: Yes, it is because Verizon has launched a service to reformat 
> the web, so users are implicitly requesting a web experience. Deep 
> down somewhere there is a link to opt-out of the service....
> Tom Hume: I still think Verizon is not compliant
> Novarra: We disagree
> ...and so on and so on...
> Not so, here is how it works:
> Tom: Please refer to which clearly states that the default 
> assumption must be that users require the original version
> [Proxies should assume that by default users will wish to receive a 
> representation prepared by the Web site. Proxies must assess whether a 
> user's expressed preference for a restructured representation is still 
> valid if a Web site changes its choice of representations (see 4.2.6 
> Receipt of Vary HTTP Header).]
> Tom: And kindly also refer to 4.2.2 which states:
> [Proxies must provide a means for users to express preferences for 
> inhibiting content transformation. Those preferences must be 
> maintained on a user by user and Web site by Web site basis. Proxies 
> must solicit re-expression of preferences in respect of a server if 
> the server starts to indicate that it offers varying responses as 
> discussed under 4.2.6 Receipt of Vary HTTP Header.]
> And Luca, ref the Vary header ... this is important to stop caches 
> caching the wrong thing, or rather to allow them to cache the right 
> thing in the presence of varying representations.
> Jo

Received on Tuesday, 23 December 2008 11:47:01 UTC