Back to the future?

In his blog post, Steve Souders describes how IE8 increases the page download performance by using more than two parallel HTTP sessions, briefly mentioning that this violates the recommendation from RFC 2616, which was, after all, written in 1999.

Some web developers might be too young to remember why RFC 2616 has the "two parallel sessions" recommendations. It was (among other reasons) a result of the disasters an earlier version of Internet Explorer (IE3?) caused on the Web infrastructure when Microsoft in its infinite wisdom decided to open multiple parallel HTTP sessions. The browsers quickly overloaded WAN links, caused server overloads (if you use 6 parallel sessions instead of two, all of a sudden the number of "visitors" increases three-fold), firewall failures (some firewalls had licenses limiting the number of parallel sessions) and potentially NAT failures (if you have to do port-address-translation, you might run out of port numbers).

But it looks like the history needs to repeat itself ... or maybe this time the infrastructure is ready for the additional load? My "what could fail" bet would be on the servers, but we'll see in a few months ...