Re: For discussion: scope for AltSvc and ORIGIN bis efforts

[Daniel Stenberg <[e-mail]>]

On Thu, 5 Nov 2020, Mark Nottingham wrote:

> Comments on this scope -- including proposals for additions -- are welcome; 
> we'll issue a Call for Adoption if we can get to a general agreement about 
> that.

For Alt-Svc, there's this little issue I've run into when playing with it for 
HTTP/3. Not sure what to do about it, but it feels like a good time to mention 
it as it is rather annoying.

Alt-Used (RFC 7838 section 5) is a request header that only sends host name + 
port number, with no hint if that port number is TCP or UDP (or ALPN name), 
which makes at least one large HTTP/3 deployment trigger its Alt-Svc loop 
detection when only swithing protocols to h3.

IOW: If we get an Alt-Svc back that says try h3 on the same host on the same 
port that we just did h1 or h2 against.

It also makes me wonder if other clients are actually not using this header or 
how have you avoided this issue?

-- 

  / daniel.haxx.se