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@swm.pp.se> To: bloat@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@swm.pp.se
On Sat, Jun 13, 2015 at 06:20:31PM +0200, Mikael Abrahamsson wrote:
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.
I recall when ECN first came out and firewalls would block it causing me issues on my Linux boxes sending list mail out. It was a small enough percentage that I mostly ignored it, but this will cause trouble for people who still haven't fixed their broken firewalls. I encourage almost everyone on nanog to watch this talk. - Jared
---------- Forwarded message ---------- Date: Sat, 13 Jun 2015 18:07:57 +0200 (CEST) From: Mikael Abrahamsson <swmike@swm.pp.se> To: bloat@lists.bufferbloat.net Subject: Apple ECN, Bufferbloat, CoDel
I highly encourage people to take a look at:
-- Mikael Abrahamsson email: swmike@swm.pp.se
-- Jared Mauch | pgp key available via finger from jared@puck.nether.net clue++; | http://puck.nether.net/~jared/ My statements are only mine.
On 6/15/15 6:19 AM, Jared Mauch wrote:
On Sat, Jun 13, 2015 at 06:20:31PM +0200, Mikael Abrahamsson wrote:
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.
you'll also find all the networks that use the entire tos field as part of the hash key... that's not exactly something you notice when you have a 1:1 host to ip correspondence unless it leads to reordering. but with stateless load balancing you can. fortunately those networks are observably rare.
I recall when ECN first came out and firewalls would block it causing me issues on my Linux boxes sending list mail out. It was a small enough percentage that I mostly ignored it, but this will cause trouble for people who still haven't fixed their broken firewalls.
I encourage almost everyone on nanog to watch this talk.
- Jared
---------- Forwarded message ---------- Date: Sat, 13 Jun 2015 18:07:57 +0200 (CEST) From: Mikael Abrahamsson <swmike@swm.pp.se> To: bloat@lists.bufferbloat.net Subject: Apple ECN, Bufferbloat, CoDel
I highly encourage people to take a look at:
-- Mikael Abrahamsson email: swmike@swm.pp.se
On Mon, Jun 15, 2015 at 9:13 AM, joel jaeggli <joelja@bogus.com> wrote:
On 6/15/15 6:19 AM, Jared Mauch wrote:
On Sat, Jun 13, 2015 at 06:20:31PM +0200, Mikael Abrahamsson wrote:
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.
you'll also find all the networks that use the entire tos field as part of the hash key... that's not exactly something you notice when you have a 1:1 host to ip correspondence unless it leads to reordering. but with stateless load balancing you can. fortunately those networks are observably rare.
I am aware of one such (very large) network that did, indeed, (and til recently!) have devices that used the entire tos field in their ECMP implementation. This led to re-ordering every time ECN "CE" was exerted on ECN enabled flows. Testing for the existence of this problem is not terribly hard (example, have a rule that periodically exerts CE on a bunch of test tcp flows, count the reorders in TCP_INFO), but the tools for it are kind of adhoc as yet. I am curious if there is a SNMP mib/cacti/mrtg/other support for reporting "CE" events in addition to loss? Although fq_codel and pie (as deployed in linux - sadly docis-pie has no ECN support in the spec) do do ecn markings (fq_codel *by default*), deployment on bottleneck links is limited as yet. :) My expectation is that this will make a difference first for apple streaming video apps in the home, connecting to other devices in the home (over wifi, ethernet, bluetooth, etc) that will start to make use of this additional signalling information. And a billion new devices with ecn on by default will probably expose all the other problems rather rapidly. ;)
I recall when ECN first came out and firewalls would block it causing me issues on my Linux boxes sending list mail out. It was a small enough percentage that I mostly ignored it, but this will cause trouble for people who still haven't fixed their broken firewalls.
Better fallbacks exist now.
I encourage almost everyone on nanog to watch this talk.
- Jared
---------- Forwarded message ---------- Date: Sat, 13 Jun 2015 18:07:57 +0200 (CEST) From: Mikael Abrahamsson <swmike@swm.pp.se> To: bloat@lists.bufferbloat.net Subject: Apple ECN, Bufferbloat, CoDel
I highly encourage people to take a look at:
-- Mikael Abrahamsson email: swmike@swm.pp.se
-- Dave Täht What will it take to vastly improve wifi for everyone? https://plus.google.com/u/0/explore/makewififast
participants (4)
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Dave Taht -
Jared Mauch -
joel jaeggli -
Mikael Abrahamsson