Hi, Very good presentation on Happy Eyeballs at the WG session today. It might indeed be true that lowering the HE "head start" for IPv6 from 300ms to 150ms might cause a slight increase in performance. However, as Geoff Huston pointed out, HE is not about getting the best performance, it's meant to move traffic to IPv6 (so IPv4 traffic will go down, and we can know when we can turn off IPv4) without breaking the user experience when IPv6 is broken. It was (and still is) an important argument for website owners to be comfortable enough to actually deploy IPv6 and not be too worried about client experience breaking. But it is also hiding IPv6 brokenness, removing an incentive for website owners to actually fixing IPv6 errors and causing IPv6 to be taken less seriously... So, how about we go the other way. We want IPv6 to be taken more seriously. What about if we change the algorithm the other way over time: give IPv6 more and more of a head start. That way IPv6 stability and performance become more important over time, without causing brokenness. Something like: HE head start = 300 + (months after 2017-01-01) * 30 That would provide some incentive to make sure that IPv6 is properly deployed and managed. Cheers, Sander