QUIC traffic throttled on AT&T residential

Wed Feb 19 21:21:28 UTC 2020

On Wed, Feb 19, 2020 at 3:34 PM Blake Hudson <blake at ispn.net> wrote:
> Yeah, that was a nice surprise to find that my tethered LTE connection
> was out performing my wired cable modem service. Of course, I had
> already signed up for a year of service and there were early termination
> fees for cancelling... that and there are no other wireline providers
> available at my home (not even ATT).

So we're left with some questions:

1. It's clear I'm not the only one experiencing this issue. How
widespread is this problem, really? Has it gotten rather worse over
the past ~year?

2. Are customers of larger ISPs much more impacted than customers of
smaller ones that (assumedly) don't have to deprioritize UDP so much?
2a. If users *are* impacted, as Blake notes, they may not be able to
switch ISPs to improve their lot.. will customers complain to their
ISP or to Google?

3. How much worse is the problem when using v4 UDP QUIC vs v6? If QUIC
only works on v6 (and if it in fact continues to actively BREAK
v4-only users), then is this v6's "killer app" that will drive
adoption?
3a. Or will this issue hinder HTTP/3 deployment (or cause mass
blocking of UDP on clients)?

4. Will ISPs be willing to give UDP traffic higher priority to improve
user experience? Will that only happen once HTTP/3 is widely deployed?

5. We can only assume Google is aware of this issue; will Google work
to improve QUIC fallback to TCP, or will they work with ISPs to get
QUIC (esp v4 QUIC) prioritized, or will they do nothing, or will they
actively encourage QUIC to break v4 at the expensive of current user
experience?
5a. Will another company that wants HTTP/3 to succeed take the mantle
and work with ISPs to improve the situation? I'm reminded of when
Microsoft worked with ISPs to ensure xbox UDP traffic would transit
properly

-- Dan