The Internet Engineering Task Force and the International Telecommunications Union are at odds over the new Multi-Protocol Label Switching (MPLS) protocol used by enterprises and carriers alike for WAN applications. Nerves are running quite high, with enterprise vendors like Cisco predicting a "catastrophe" and a "train wreck."
What's happening is a disagreement over the EtherType used in the new Transport-MPLS protocol that the ITU has proposed for trunk and backbone carriers. Some people are saying that employing the same EtherType for both MPLS and T-MPLS makes it impossible for other network components to tell them apart. If they can't process packets for the two versions independently, that could lead to general network confusion and possible shutdown.
The ITU counters that the two versions are fully compatible, so it doesn't matter if other components can't tell them apart. Besides, they've been working on T-MPLS with the standard EtherType for several years now and it would require a lot of reverse engineering to change.
The two sides are set to meet next week in Germany, and since there's an awful lot of money at stake here, they really have no choice but to hammer out a compromise. But even if they can't, there's still plenty of time to run some real world crash tests before the train actually wrecks.