QLogic Learns Brocade Lingo

Does end run around Brocade, reverse-engineering its proprietary 'native mode' operation

July 26, 2003

3 Min Read
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After years of incompatibility issues among different vendors' Fibre Channel switches, QLogic Corp. (Nasdaq: QLGC) has made a minor breakthrough: The company has successfully reverse-engineered Brocade Communications Systems Inc.'s (Nasdaq: BRCD) "native mode" operation, allowing its switches to function as members of a Brocade SAN fabric, Byte and Switch has learned.

QLogic quietly made the option available with the release last month of a firmware upgrade for its SANbox2 family of 2-Gbit/s FC switches. The new feature would theoretically allow QLogic switches to work with Brocade's advanced fabric-management features, such as performance monitoring and hardware-enforced World Wide Name (WWN) zoning. Hardware-enforced WWN zoning ensures that only designated devices are able to access specific physical switch ports.

To some extent, Brocade switches are already interoperable with third-party switches via the E_port (or "expansion port") protocol. However, in this configuration Brocade switches disable all advanced functions.

An independent storage industry consultant, who wishes to remain anonymous, points out that Brocade generates additional revenue by selling advanced fabric features -- and therefore has a vested interest in making sure those features work only with Brocade's own switches.

"Anything [Brocade] makes money on is disabled in E_port mode," he says.Ironically, in order to allow QLogic switches to work natively with Brocade switches, users must disable FC-SW-2 mode. FC-SW-2, which stands for "Fibre Channel Switched," is the American National Standards Institute (ANSI) standard governing connectivity among nodes in a Fibre Channel fabric.

According to the release notes for QLogic's firmware version 2.0.0.03, made available on June 25: "QLogic switches have always been FC-SW-2 compliant; this is the default/enabled behavior. When FC-SW-2 Compliant mode is disabled, QLogic switches will interoperate with Brocade switches in their native mode."

QLogic, in the release notes, says it has tested native interoperability with Brocade's SilkWorm 2400, 2800, 3800, and 3900 switches. The document is available at http://download.qlogic.com/sf/11418/relnotes_fullimage_2.0.0.03.pdf.

The storage consultant suggests that QLogic is not widely publicizing the feature because it fears Brocade may quickly update its own code so those advanced functions don't work with QLogic's Brocade-native firmware. "They're keeping this low-profile because they don't want to piss off Brocade," he says. [Ed. note: Oops -- too late.]

QLogic and Brocade representatives did not respond to requests for comment by press time.Meanwhile, Cisco Systems Inc. (Nasdaq: CSCO) is also said to have developed the ability to let its MDS 9000-series switches operate with Brocade gear in native mode, our sources say. Cisco spokesman John Noh says he is unaware of any such project.

It should be noted that other Fibre Channel vendors have implemented nonstandard, "extended" features that don't work with other vendors' switches. For example, Cisco's proprietary Virtual SAN (VSAN) feature, which lets users create isolated fabrics running on the same physical infrastructure, does not extend across third-party switches (see Cisco's VSANs: Hype or Innovation?).

Randy Kerns, senior analyst at storage consulting firm Evaluator Group, says all the Fibre Channel switch vendors take advantage of "flexibility" in the FC-SW-2 specification to create differentiating features. "The important thing is that they have the ability to interoperate if you so choose," he says. "There's nothing nefarious here -- just competition."

But others believe Brocade, in particular, is still actively trying to inhibit interoperability in order to protect its installed base. Earlier this year, Brocade was the only FC switch vendor that refused to participate in the Storage Networking Industry Association (SNIA)'s multivendor switch interoperability demonstration (see Brocade Snubs Multivendor Demo).

"The real question is that if Cisco or QLogic can make this work from their end, why can't Brocade make this work on their end?" says our source. "Of course, they could... They're doing it to hold on to their turf. They're blocking instead of innovating."Todd Spangler, US Editor, Byte and Switch

A detailed examination of the SAN switch segment is included in the current Byte and Switch Insider report -- "Fibre Channel Market Update" -- which is available here

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