Re: comments on draft-mbelshe-httpbis-spdy-00

Patrick's idea is the happy eyeballs approach (see related work on IPv6
by Dan Wing et al). You're right, tho, that you probably can't do it in
a single packet, but multiple rapid fired. That solves the issue you
raise below.
Eliot
On 8/15/12 8:23 PM, William Chan (陈智昌) wrote:
> I'm confused by this comment. My understanding is that multiple
> questions per query does not work in practice. Also, how does the
> response work? If the A record is cached, but the SRV record is
> uncached, does the server not respond to the client until the SRV
> record comes back? Or does it stream the records back somehow and have
> the client block on responses?
>
> Patrick's explanation makes more sense to me.
>
>
> On Wed, Aug 15, 2012 at 10:40 AM, Eliot Lear <lear@cisco.com
> <mailto:lear@cisco.com>> wrote:
>
>
> On 8/15/12 7:19 PM, William Chan (陈智昌) wrote:
>> Can you elaborate how SRV would work here from a client
>> perspective? Do you propose making the client block on the SRV
>> lookup? Or are you proposing doing this out of band and switching
>> to HTTP/2.0 if we discover support?
>
> Block is the wrong word. You're already doing A-Record queries. 
> Adding another record in the question only adds latency if you
> must serially query. Also, I myself am not convinced that SRV
> records are sufficient to the task. For instance, what happens if
> there is a port # in the URL? How do you identify the version #? 
>
> Paul Hoffman did some work on a draft that sort-of looked at this
> problem. I'm going to guess that he stopped short because of
> potential downgrade attacks.
>
> Eliot
>
>