Any guaranteed bandwidth offered on an Ethernet-based network can only be provisioned through the cooperative benevolence granted by a lot of parties that are involved, due to Ethernet's hierarchical nature, thus making Ethernet an inexact science, so its gotta go. There's even something called DataCenter Ethernet, presumably created by some form of verbal agreement, so Ethernet is not even science.

InfiniBand is point-to-point Layer-2 technology that's done right. IPv6 running over InfiniBand using a flat routing model, preferably OSPF, must soon be deployed around the planet for all access to the Internet.