SBC Lights Up SANs (In Theory)

Disaster recovery prompts carrier to offer SAN services, but where does this leave the SSPs?

October 4, 2001

4 Min Read
Network Computing logo

Today SBC Communications Inc. (NYSE: SBC) rekindled its on-and-off relationship with Nortel Networks Corp. (NYSE/Toronto: NT). SBC plans to purchase DWDM (dense wavelength-division multiplexing) metro optical switches from Nortel with an aim to boost the bandwidth of long-distance storage.

The deal calls for SBC to buy gear from Nortel on an as-needed” basis (i.e., a contract without specific terms) to connect mainframes, data centers, and storage networks within a metropolitan area.

Backing up and mirroring data across cities and among data centers has become a real issue for many of the world’s largest corporations -- especially in light of the September 11 attacks. But as the market develops, it's clear that wide-area storage services are still not the mass market that many would like them to be.

"There aren’t a ton of companies out there that need this, but those that do are big deals, and we are getting calls about it,” says Ashley Blaker, communications spokesman at SBC.

What are the barriers to boosting the wide-are storage services market? The largest challenge to such services are the protocols used to provide them, such as ESCON (Enterprise Systems Connection, invented by IBM to connect its mainframes together) and Fibre Channel.According to Tom Aellis, former chief optical networking engineer at GiantLoop Network Inc., these technologies were designed for relatively short distances.

"There is a huge distance-versus-throughput limitation that eithermost carriers do not understand or do not present to their customers," says Aellis. For example, the maximum data rate of a native ESCON link is 18.6 Mbit/s -- and that channel can maintain its speed up to just 8 kilometers. "As the distance is increased, throughput is surrendered," he says.

Perhaps the renewed interest in business continuity plans will force the market to address these issues.

The same goes for the use of DWDM switching technology in metropolitan areas. Here the issue is more about cost. DWDM packs more data streams over the same optical fiber pair by using different colors of light, a cheaper alternative to laying more and more fiber. But until recently it has been predominantly deployed in long-haul networks.

No so anymore, says SBC. "As [DWDM] has matured and more people have bought it, the price per channel has fallen, making it a cost-effective alternative to running a pair of fibers across a city to connect sites together," says Blaker.SBC’s multiservice optical networking (MON) service is a dedicated point-to-point network that transmits data at speeds of up to 2.5 Gbit/s per wavelength. It claims to support up to 160 Gbit/s of unprotected traffic or 80 Gbit/s of protected traffic on the fiber, although the service doesn't specify the distance over which this is offered.

The service supports a range of transport protocols, including ESCON, FICON, ETR, ISC, Fibre Channel, Fast Ethernet, Gigabit Ethernet, Sonet, and D1 video. SBC will offer the service as a managed wavelength service or will furnish the wavelengths for customers to manage themselves, depending on customer preference.

"Some particularly sensitive firms -- like banks -- want the assurance that no one else is tinkering or making changes on the equipment or configuration,” says Galen Schreck, analyst with Forrester Research.

SBC isn't alone in pursuing wavelength services for storage networking. GiantLoop, one of the next generation optical metro carriers, has hooked up with McData Corp. (Nasdaq: MCDT) to connect Fibre Channel SANs over optical networks (see McData Goes a Little Loopy). Global Crossing Ltd. (NYSE: GX) also reportedly has a plan in the pipeline. Others are expected to follow.

All these efforts have a distinct downside for struggling SSPs (storage service providers). Analysts say companies such as StorageNetworks Inc. (Nasdaq: STOR) don't own their own facilities and are having a very difficult time acquiring the fiber assets they need to deliver their services to and from customers. And they're hopping mad when the carriers they seek to buy fiber from start to compete with them. A recent lawsuit filed by StorageNetworks against Metromedia Fiber Network Inc. (MFN) (Nasdaq: MFNX) clearly touches on this issue (see StorageNetworks Sues MFN).The situation won't be helped as carrier giants like SBC stomp into this space. SBC plans to offer its new metro optical services through all its local subsidiaries -- SBC Southwestern Bell, SBC Ameritech, SBC Pacific Bell, SBC Nevada Bell, and SBC SNET.

— Jo Maitland, Senior Editor, Byte and Switch

Stay informed! Sign up to get expert advice and insight delivered direct to your inbox

You May Also Like

More Insights