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

Cameron Byrne cb.list6 at gmail.com
Sat Jun 9 07:24:09 CEST 2012


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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