A colleague of mine pointed something out the other day: the numbers and letters that make up the Nexus 2000 (FEX) model actually have meaning! No, I haven't been living under a rock. I think it's pretty clear that with a model number like "2248TP-E" the "22" indicates this is the 2200 series FEX and the "48" indicates it's got 48 ports. But what about the letters that follow the numbers?

This is a quick, high level rundown of Cisco's various fabric extender technologies and where each fits into the data center.