Re: UDP source ports for HTTP/3 and QUIC

[Willy Tarreau <[e-mail]>]

On Thu, Jul 15, 2021 at 11:53:46AM +0200, Stefan Eissing wrote:
> > Am 15.07.2021 um 11:29 schrieb Willy Tarreau <[e-mail]>:
> > 
> > On Thu, Jul 15, 2021 at 10:56:28AM +0200, Mikkel Fahnøe Jørgensen wrote:
> >> It is perhaps worth noting that due to QUIC (optionally) having unique
> >> connection identifiers, it is feasible to have many connections on the same
> >> source port. Therefore that could be a recommendation in cases where some
> >> source ports might be blocked.
> > 
> > I think that this is an excellent idea! The simple fact that this is
> > being discussed precisely is because the source port serves no purpose
> > here other than being compatible with UDP. So basically we could have
> > a recommendation that each application preferably uses a single socket
> > and source port for outgoing communication. This will also lower the
> > stress on source port allocation (and recycling) as well as the need
> > for file descriptors.
> 
> Yikes, all QUIC packets will potentially arrive a the same child listener.

That's a good point, indeed. But we could suggest that for low network
resource usage (i.e. browsers), reusing sockets that proved to work fine
is recommended.

> Let's go all the way and defined a fixed source port. ^^

:-)

Willy