happy CGN -- beating happy eyeballs and trending toward E2E success

Eric Vyncke (evyncke) evyncke at cisco.com
Wed Jun 13 09:48:21 CEST 2012

Mac OS/X 10.6.8 over wireless (whose quality is not perfect):
- page 1: IPv6, and always IPv6
- page 2: IPv6, then always IPv4 

iPad 5.1.1 (same WiFi as Mac OS/X)
- page 1: IPv4, and always IPv4
- page 2: IPv4, and always IPv4

Hope it helps


> -----Original Message-----
> From: ipv6-ops-bounces+evyncke=cisco.com at lists.cluenet.de [mailto:ipv6-ops-
> bounces+evyncke=cisco.com at lists.cluenet.de] On Behalf Of Cameron Byrne
> Sent: vendredi 8 juin 2012 22:24
> To: IPv6 operators forum
> Subject: happy CGN -- beating happy eyeballs and trending toward E2E success
> Hi,
> During v6launch, i heard a fair amount of chatter that "happy eyeballs" has
> had a bit of a negative impact on traffic levels.
> Meaning, people who move a lot of content and keep stats on who does what
> and when, know that Apple's implementation of happy eyeballs is moving
> traffic over IPv4 when it can be over IPv6.
> This is not news
> https://labs.ripe.net/Members/emileaben/hampered-eyeballs, but now that it
> is past v6launch, it is real and traffic impact is real, and ... for people
> with CGNs, it's even more real since the offload from CGN to IPv6 is not
> happening (business case for IPv6 looking a little weak, promises about CGN
> off load  not kept, traffic projections and peering builds-- back to the
> slow track , blah...)
> So, there are explorations on how to beat happy eyeballs, especially Apple's
> happy eyeballs.  This is becoming an arms race, but so be it.
> Maximizing on 5ms delta to a web browser is not an objective of any network
> providers that has a CGN that i know of.  Minimizing state / scale in a CGN
> is an objective... in fact, there are many who say IPv6 only gets deployed
> because they fear the CGN.  So, if we deploy IPv6 to not have to deal with
> the CGN, but happy eyeballs does not get the traffic off of the CGN ....
> something must be done.
> Being a hack, i always look to solve problems with DNS trickery first:
> Would aggressive caching of AAAA and aggressive non-caching of A result in
> beating happy eyeballs on OSX?
> I don't own any Apple products, so i cannot test this myself.
> i setup a very simple test web page
> http://test1.cgn.strangled.net/b.shtml
> DNS TTL = 1 day for A and AAAA (the control)
> and
> http://test2.cgn.strangled.net/b.shtml
> DNS TTL = 1 day for AAAA and 1 second for A (the experiment)
> To get the effect, you would need to refresh a few times to prime the DNS
> cache.
> Let me know your thoughts and results.
> CB

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