Optical/IP Networks

Entrada Adds CWDM to Storage Switch

LAS VEGAS -- At the NetWorld+Interop trade show here today, Entrada Networks (Nasdaq: ESAN) is unveiling a four-port storage area networking (SAN) extender based on the economical fiber-optic technology, CWDM (coarse wavelength-division multiplexing).

The product, called Silverline-WDM, gives enterprise and carrier customers a fast and economical way to link various "islands" of networked storage in buildings and campuses, using the cheap, available bandwidth provided by fiber-optic-based WDM technology. This would help fuel the use of emerging optical services by using metropolitan networks for storage applications.

Analysts say the move is a positive one for Entrada. "It's a good strategic play," says Nancy Marrone, senior analyst at the Enterprise Storage Group Inc.. "It gets them away from being a point product provider to offering SAN solutions."

When Entrada announced its first product, the Silverline 222, last fall, it certainly ran the risk of being classed as a point product provider. That device, classed as a "SAN router" by Entrada, is designed to do one thing -- switch data traffic between Fibre channel and gigabit Ethernet interfaces.

"[The Silverline-WDM] is aimed at customers who need point-to-point links between SAN islands and optical network services," says Entrada VP of marketing Mike Harris.

Today, Harris says, customers spend big bucks for complicated leased-line connections among locations that support network-attached storage, Fibre channel SANs, and mainframe-attached devices. Alternatively, they invest in expensive multichannel optical platforms with SAN connectivity, such as those offered by ADVA AG Optical Networking (Neuer Markt: ADV, Lucent Technologies Inc. (NYSE: LU), or ONI Systems Inc. (Nasdaq: ONIS).

Harris says with Silverline-WDM customers will be able to run different types of storage traffic over the same fiber via WDM. And he hints that Entrada's eager to promote its product as simpler and cheaper than optical platforms with SAN support.

On the downside, the new product does not have integral switching capabilities of its own. While it converts data from one interface to another and can multiplex streams of storage traffic together, it isn't able to actually switch from one link to another. Therefore, it must be used as an adjunct to switching gear like the Silverline 222 or third-party Fibre Channel switches.

"We plan to integrate the Silverline 222 with WDM product in the future," a spokesperson says. "Until then, this box is a cheap way to extend Fibre channel links another 80 kilometers over light."

According to Entrada, that's a market with plenty of demand. "We estimate that 40 to 45 percent of enterprises and carriers have access to the optical backbone," Harris says. He contends the box will let them take advantage of that proximity without breaking the bank.

Initially, the Silverline-WDM will offer two to four ports, capable of sending bidirectional traffic over eight wavelengths (four channels) on singlemode fiber. The switch will convert data traffic between Fibre channel and gigabit Ethernet interfaces at first, with ESCON and FICON mainframe channel interfaces to come in a following release. It will support Sonet OC3 (155 Mbit/s), OC12 (622 Mbit/s), and OC48 (2.5 Gbit/s) connectivity.

The new Silverline-WDM won't be in beta tests until the end of this year, and it won't ship until the first quarter of 2002.

- Mary Jander, Senior Editor, Light Reading http://www.lightreading.com
PBC 12/4/2012 | 8:28:01 PM
re: Entrada Adds CWDM to Storage Switch Could I please get a definition of coarse wdm as well as a quick education as to its benefits?


joestudz 12/4/2012 | 8:28:01 PM
re: Entrada Adds CWDM to Storage Switch Go visit the LMNE and MRVC web sites for a insight to CWDM technology. Wonder if LMNE is supplying the CWDM modules for this SANS application?
StartUpGuy1 12/4/2012 | 8:27:59 PM
re: Entrada Adds CWDM to Storage Switch CWDM does not conform to any ITU grid patttern. It cannot be used in place of ITU grid optics due to the use of uncooled lasers and the non-standard channel spacing.

In a nutshell, CWDM provides a cheap way to multiplex 4 to 8 wavelengths of OC-3 to GigE traffic.
ofer_fi 12/4/2012 | 8:27:59 PM
re: Entrada Adds CWDM to Storage Switch Does CWDM is standartized in ITU-T or other ?, What is the grid been used ?
fibernet 12/4/2012 | 8:27:56 PM
re: Entrada Adds CWDM to Storage Switch CWDM has an advantage over DWDM in 3 areas.

1. Power -A DWDM laser transmitter with TEC (Thermo Electric Cooler) uses significantly more
power than a CWDM transmitter which does not have one.

2. Cost- A DWDM DFB costs about 3 to 4 times more that a CWDM DFB. A CWDM DFB has
only the Laser + a monitor photodiode, also the wavelength tolerance is not as stringent.

3. Space- DWDM Transmitters have a Temp. measurement loop and a TEC loop to maintain
temperature stability, which is not required in CWDM systems.

As far as standards go, they are still being worked out. Most of the passive vendors out there are
selling filters at 1510 nm, 1530 nm, 1550 nm and 1570 nm, the passband on the filters are typically +/-
7 nm. The laser vendors are are at the same wavelengths with +/- 3 nm variation.

Bluebeam 12/4/2012 | 8:27:21 PM
re: Entrada Adds CWDM to Storage Switch See


for some info on ITU efforts for CWDM standardization.
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