Blaze hits the Xenpak trail

By Peter Heywood
Network World Optical Networking Newsletter, 01/02/02

Blaze Network Products recently announced it had shipped 10G bit/sec transceivers that comply with the new Xenpak form factor, a multisource agreement led by Agilent Technologies and Agere Systems.

Sound familiar? It should. Although Blaze claims it's the first with a 10G bit/sec Xenpak transceiver, back in September, Agilent announced that it had the first commercially available 10G bit/sec Ethernet Xenpak-compliant module.

So which company is actually the first? The answer is that they both are, technically. The Blaze product is based on coarse wavelength-division multiplexing (CWDM) technology, which means that its module combines four 1310 nanometer lasers that transmit traffic at between 2.5G bit/sec and 3.125G bit/sec each into one module, for a combined throughput of just over 10G bit/sec.

Agilent, on the other hand, has developed a 1310nm serial laser module. This means that it uses one laser to transmit signals at 10G bit/sec. Both products adhere to the Xenpak form-factor specification, which simply means that they are packaged in the same form factor so that networking system vendors such as Cisco or 3Com can use either transceiver interchangeably, depending on customer requirements.

According to Kirk Bovill, director of marketing for Blaze, its 10Gbase-LX4 solution can transmit signals up to 10 kilometers over singlemode fiber, and in some cases, can be stretched up to 20 or even 25 kilometers. Agere just announced it will be shipping in January its 10G bit/sec Xenpak modules, which can transmit up to 10 kilometers.

The real difference between the approaches comes when comparing transmission distances over multimode fiber, the most commonly installed fiber in enterprise networks. In this environment, Blaze claims that its module transmits signals up to 300 meters. Neither Agere nor Agilent specify transmission distances over multimode fiber, yet both companies claim their modules are geared toward enterprise networks and metro networks, which tend to have singlemode fiber installed. What's more the IEEE has not specified distances for serial transmitters over multimode fiber.

So what's the difference? It may come down to different market segments. Bovill says companies like Cisco and 3Com have publicly stated that to fulfill many of their customers' requirements, they need solutions that can transmit signals up to 300 meters over multimode fiber. So yes, this could be a big deal for products in the enterprise market.

"The 10GBase-LX4 transceiver is the optimal solution for 10G bit/sec Ethernet in the enterprise space," said Shaun Paice, business strategy manager at 3Com's Business Networks Company, in the Blaze press release. "It addresses two of the IEEE 802.3ae distance objectives for multimode and singlemode cable plants through a single port. This makes it easier for customers to implement 10G bit/sec Ethernet and protects their existing cabling investments."

Blaze isn't the only company adhering to the IEEE 802.3ae 10GBase-XGLX4 standard. Molex and Pine Photonics Communications are also working on products. Earlier in September, the three companies completed vendor-to-vendor testing to ensure that the interoperability requirements of the IEEE specification were satisfied.

While serial applications seem to be geared primarily for metro applications, Bovill says that CWDM 1300nm solutions like Blaze's are suited for either metro or enterprise applications.

"I think that in the private metro area network market, which includes educational networks and utilities networks, we would be optimal, since it is a point-to-point link that would have some mix of multimode and singlemode cable plant, " he says.

Bovill says that Blaze is currently shipping to over 25 customers, with roughly 500 units already installed in customers' gear.

Marguerite Reardon is a senior editor of Light Reading (www.lightreading.com), an optical networking Web site. She can be reached at reardon@lightreading.com