The requirement for ALPN is a client-side requirement. Chrome is dropping NPN and moving to ALPN in <i>recent</i> releases[0].<p>0: <a href="http:&#x2F;&#x2F;blog.chromium.org&#x2F;2016&#x2F;02&#x2F;transitioning-from-spdy-to-http2.html" rel="nofollow">http:&#x2F;&#x2F;blog.chromium.org&#x2F;2016&#x2F;02&#x2F;transitioning-from-spdy-to-...</a>