Re: [alto] HTTP Review (draft-ietf-alto-new-transport)

[Mark Nottingham <[e-mail]>]

I've taken a look at this document. 

My high-level feedback is that in principle it's reasonable use of HTTP, but how it talks about HTTP versioning and a few other details isn't appropriate. I think that a few small editorial updates could improve things, and would be happy to make a pull request if you happen to be using a Github-based process.

What raises concerns for me is referring to this as 'ALTO/h2' and similar things. If you're designing an application that uses HTTP, you need to acknowledge that you can't always control the end-to-end version of the protocol used, and while you can optimise for newer versions of the protocol, you have to be prepared for downgrading to previous ones.

That means that this isn't really "ALTO/h2", it's a new version of ALTO that operates more smoothly under later versions of the protocol. 

DoH threaded this particular needle as well; rather than branding it as "DNS/h2", they merely said " HTTP/2 [RFC7540] is the minimum RECOMMENDED version of HTTP for use with DoH." and then: "Earlier versions of HTTP are capable of conveying the semantic requirements of DoH but may result in very poor performance."

In this spirit, I'd recommend avoiding using the HTTP/2 textual representation for examples; most developers are much more familiar with HTTP/1.1 when consuming examples, and HTTP/2 contains details which aren't relevant for the purpose of conveying an example (we've settled on this approach in the HTTP editorial style, see <https://httpwg.org/admin/editors/style-guide>).
 
Note that I haven't done a full review; these are just the things I saw after a quick look.

Cheers,



> On 11 Jul 2022, at 1:37 pm, Mark Nottingham <[e-mail]> wrote:
> 
> Hi folks,
> 
> I've been asked to forward this request for early review; does anyone want to take a look?
> 
> Feedback to [e-mail].
> 
> Cheers,
> 
> 
>> Begin forwarded message:
>> 
>> From: <[e-mail]>
>> Subject: HTTP Review (draft-ietf-alto-new-transport)
>> Date: 6 July 2022 at 12:56:56 am AEST
>> To: Mark Nottingham <[e-mail]>
>> Cc: Qin Wu <[e-mail]>, "[e-mail]" <[e-mail]>
>> 
>> The ALTO WG is currently working on the specification available at:https://datatracker.ietf.org/doc/draft-ietf-alto-new-transport/. The current version focuses on H2 with the intent to cover at least common H2/H3 functionalities.
>>  
>> The WG is seeking for early reviews so that issues/advice are taken into account early in the process.
>>  
>> We are particularly interested in comments about the handling of H3, especially with regards to the guidelines in RFC9250 about HTTP versioning.
>>  
>> Of course, comments related to other considerations in the draft are more than welcome.
>>  
>> Thank you.
> 

--
Mark Nottingham   https://www.mnot.net/