Apple ECN, Bufferbloat, CoDel (fwd)

Sat Jun 13 16:20:31 UTC 2015

Hi,

I just want to bring to your attention the below talk (I am too lazy to 
re-write the whole email for this slightly different audience).

Takeaway:

We'll see a lot of ECN enabled traffic in a few months. This shouldn't be 
a problem. I've been doing it to all my machines for 3-5 years without ill 
effects.

More people will become interested in how TCP works, from application, 
through the host stack, to the AQM (or lack thereof) in the router etc. If 
you don't do AQM towards your customers, be prepared that they're going to 
start complaining in a more informed manner in the not so distant future.

IPv6 only with NAT64+DNS64 will become a lot more feasible going forward. 
I am not a fan of breaking DNSSEC, but perhaps if we can do the DNS64 in 
the host (as it seems Apple is doing, at least for IPv4 literals), then 
that might be possible to work around.

---------- Forwarded message ----------
Date: Sat, 13 Jun 2015 18:07:57 +0200 (CEST)
From: Mikael Abrahamsson <swmike at swm.pp.se>
To: bloat at lists.bufferbloat.net
Subject: Apple ECN, Bufferbloat, CoDel

I highly encourage people to take a look at:

https://developer.apple.com/videos/wwdc/2015/?id=719 (you might have to 
reigster as an apple developer to watch it, I don't know)

"Your App and Next Generation Networks
IPv6 is growing exponentially and carriers worldwide are moving to pure IPv6 
APNs. Learn about new tools to test your apps for compatibility and get expert 
advice on making sure your apps work in all network environments. iOS 9 and OS 
X 10.11 now support the latest TCP standards. Hear from the experts on TCP Fast 
Open and Explicit Congestion Notification, and find out how it benefits your 
apps."

Being on this list you might not learn much from the talk, but I really 
appreciate a talk aimed at a wider (developer) audience which so clearly 
outlines the benefits of ECN, CoDel and TCP host opimization to reduce 
end-to-end experienced application communication latency. One of the major 
takeaways is that Apple is planning to by default enable ECN in iOS9 and OSX 
10.11. This would mean hundreds of millions of devices will be using ECN in a 
few months.

You can skip to 16 minutes into the talk if you're not interested in the new 
requirement for applications to support an environment where it's Internet 
access is IPv6 only behind NAT64+DNS64 (I'm myself super excited about this).

Let's hope this brings a lot of buzz and requests towards device manufacturers 
to start supporting ECN marking and AQM. Apple is usually a good megaphone to 
bring attention to these kinds of issues...

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se