"McData went and just said, 'Here QLogic, here's McData's firmware,'" Blackman says. According to Blackman, each McData switch consumes an excessive number of domain IDs. He says that Cisco, which he is also bringing on, has expressed its willingness to work with McData on interoperability, but McData is not receptive to other vendors.

Blackman says that Cisco has told him they are willing to work with McData on interoperability before Cisco comes out with a new rev of firmware to ensure it's qualified.

"That's what you should be doing, right? In a shop that has a true interoperable environment, where you're connecting Ciscos and McDatas. The same should hold true with McData and QLogic," Blackman says.

Clark says he understands users have problems because they introduced additional vendors into a fabric. But, he notes, "if you are talking about a multivendor fabric and you are adding Brocade, McData or Cisco in the fabric itself, then yes, you can have issues, and the issues can be on anyone's side."

Clark says that McData -- along with Brocade Communications Systems Inc. and Cisco Systems Inc. -- is compliant with the FC-SW2 NSI standard that describes a Fibre Channel network in which nodes are connected to a fabric topology by one or more switches. So there's no reason Blackman or others should experience interoperability problems, he says. Beyond that, Clark adds, McData has worked "tirelessly" to develop and support industrywide interoperability standards.