Speed and convergence characterize storage networks

When Fibre Channel over Ethernet (FCoE) technologies and specifications were in development, their clear target application was the integration of a data center's storage area network (SAN) and local area network (LAN).

From the June, 2014 Issue of Cabling Installation & Maintenance Magazine

While the promise of Fibre Channel over Ethernet may not yet have come to fruition, storage area networks continue to evolve.

by patrick mclaughlin

When Fibre Channel over Ethernet (FCoE) technologies and specifications were in development, their clear target application was the integration of a data center's storage area network (SAN) and local area network (LAN). FCoE facilitates the encapsulation of dominant SAN application Fibre Channel packets within Ethernet packets, and has been described as a unifying fabric for the two network types.

Now available to the market for several years, FCoE has faced the dreaded label of not living up to its potential. Or hype. In a recent research note, Dell'Oro Group (www.delloro.com) senior analysts Casey Quillin and Sameh Boujelbene comment, "It's been a bit of a bumpy ride for FCoE. In theory, the benefits of a single converged LAN/SAN network are fairly easy to see. The problem was, as is often the case with new technology, most of the theoretical benefit was not available on the initial product release. The idea that storage traffic was no longer confined to expensive SANs, but instead could run on the more-commoditized and easier-to-administer IP equipment was intriguing. However new 10-Gbit/sec Enhanced Ethernet switches were not exactly inexpensive, with few products supporting FCoE initially. And those that did, did not play nicely with products from other vendors."

The analysts also explained that to date, nearly all FCoE adoption has been what's called single-hop, "meaning that FCoE is being deployed to provide connectivity between the server and the top-of-rack switch. Consequently, traffic continues to be broken out one way for IP and another way for FC. Breaking out traffic makes sense; by consolidating network adapters and cables, it adds value on the server access side."

Enabling versus deploying

The research note also sheds light on the reality that there is a "wide difference between the portion of 10-Gbit/sec ports that is FCoE-enabled and the portion that is actually running storage traffic. We currently believe less than a third of the FCoE-enabled ports are being used to carry storage traffic … because the FCoE port, in many cases, is provided by default with the server. That's the case with HP blade servers as well as Cisco's UCS servers, which together are responsible for around 80 percent of the FCoE-enabled ports."

Research and analyst firm Infonetics (www.infonetics.com) also addressed this issue recently when it announced 2013 year-end reports on data center network equipment as well as SAN and converged data center network equipment. At that time, Infonetics directing analyst for data center and cloud Cliff Grossner commented, "There's still room for best-of-breed in the Ethernet switch market, but as the industry moves beyond early adapters and the early market for data center fabrics, the next wave of adoption has to be made simpler for the ‘Main Street' buyer. This will keep the market for best-of-breed solutions healthy even as a portion of the data center Ethernet switch market turns to bundled solutions.

"The shift to cloud-architected data centers with automated deployment of virtual workloads will require storage networking to be more agile, driving the need for a converged network with storage and application traffic on Ethernet."

Among the studies' findings were that nearly half of the converged data center network ports shipped in the fourth quarter of 2013 would carry storage traffic. "Ethernet switch ports-in-use for storage [will] reach 55 percent of all data center purpose-built switch ports shipped in 2018," Infonetics projected, adding, "Switch ports-in-use for FCoE are expected to account for 22 percent of all data center purpose-built ports shipped in 2018."

Emergence of 16G

Both Infonetics and Dell'Oro have reported on the 16-Gbit/sec Fibre Channel market. In June 2013 Dell'Oro noted with interest that "Cisco announced their new 16-Gbit/sec Fibre Channel director class switches … This product marked Cisco's first new FC chassis since the MDS 9500 began shipping more than a decade ago." Overall the Fibre Channel switch market was weak at that time, with Dell'Oro tracking Fibre Channel switch and adapter revenues declining 10 percent for Q1 2013.

Not long after Cisco's introduction, Infonetics reported that 16-Gbit/sec Fibre Channel was "taking the market by storm," and forecasting that the market for 16G would surpass that for 8G by the end of 2013. Infonetics co-founder and principal analyst for carrier networks Michael Howard noted in October 2013, "Cisco's 16G Fibre Channel ports are finally hitting the market, and we believe its customers' pent-up demand for Fibre Channel inter-switch connection will help push 16G revenue past 8G by the end of 2013. Meanwhile, Brocade, which enjoyed a similar jump start when it came to market with 16G Fibre Channel in 2011, is settling in for the longer-term replacement of 8G as the speed of choice."

Also at that time, Infonetics reported a strong jump in the market for converged networking equipment, including FCoE. It said: "In 2Q13, the worldwide high-performance interconnect equipment market, including converged FCoE/Ethernet switches and converged network adapters, grew 26 percent sequentially and is up 43 percent year-over-year."

More recently-in March 2014-Infonetics released a report on vendor market share as well as preliminary analysis for 2013's fourth quarter as well as year-end performance in the market for SAN and converged data center equipment. That report combined positive news with negative, as the overall SAN market (comprising Fibre Channel switches and adapters) declined 7 percent from the year-ago quarter but grew by 14 percent sequentially. "The converged data center network adapter market is up 12 percent in 2013 from 2012," the firm said, "with CNAs in the lead, followed by iSCSI adpaters; universal adapters are at the back of the pack."

Grossner observed, "We've got a two-way horse race in the converged data center network adapter market. QLogic's purchase of Brocade's adapter business and Broadcom's Ethernet controller business will put QLogic in the number-two spot behind Emulex when the deal closes later this year. Emulex is firing back with 40GE converged network adapters, which it will begin shipping this quarter [Q1 2014]-the first adapter vendor to do so."

Revisiting the research note published by Dell'Oro's Boujelbene and Quillin, they concluded with the following outlook: "Whether FCoE-enabled ports are used to carry storage traffic or not, they are being introduced at the expense of some FC adapters. If users deploy a server with an FCoE-enabled port, they most likely will not buy an FC adapter to carry storage traffic. Additionally, as Ethernet speeds reach 40 Gbits/sec, the differential over FC will be too great and FC will be less likely to keep pace."

In the storage area networking market, the combination of speed and convergence appear to be driving innovation and deployment.

Patrick McLaughlin is our chief editor.

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