Cisco expected to pop optical switch

Cisco Systems Inc. is expected to launch next week optical products that observers believe will include an STS-1 grooming switch for the metro core.

At the NFOEC conference in Dallas, Cisco is expected to unveil an STS-1 grooming switch that up to now has been a gap in Cisco's optical product portfolio. Cisco killed the ONS 15900 Wavelength Router for the long-haul network last year in part because it lacked STS-1 grooming capabilities.

STS-1 grooming is a capability whereby 2.5G bit/sec or 10G bit/sec wavelengths are efficiently packed with SONET traffic broken down into STS-1 -- 52M bit/sec -- increments.

Michael Howard, principal of Infonetics Research Corp. in San Jose, believes Cisco will roll out the ONS 15600, a 64x64 STS-1 switch. Howard also believes Cisco will announce a new ONS 153XX device for the edge with dense DS-3 electrical interfaces to feed the 15600.

"This will be suitable for a BellSouth (Corp.) or SBC (Communications Inc.) network," Howard says. "The (ONS) 15454 optical connection are just not dense enough for an RBOC network."

The ONS 15454 is a SONET transport system obtained from Cisco's multibillion dollar acquisition of Cerent in 1999 that has been very successful in metro networks. Cisco claims to have more than 600 customers for the 15454.

A Cisco spokeswoman said Cisco does not comment on unannounced products when asked about the 15600.

Howard believes the 15600 will go up against Ciena Corp.'s MetroDirector K2 SONET platform. The 12-slot, 480G bit/sec MetroDirector K2 combines the functions of a digital cross-connect, SONET/SDH add/drop multiplexer, ATM switch and dense wavelength division multiplexer (DWDM).

The MetroDirector K2 offers interfaces ranging from DS-1/E1 to OC-192/STM-64, and supports 10/100 Ethernet and Gigabit Ethernet, in addition to ATM. It can be configured in linear, ring and star topologies.

Another analyst, however, believes Cisco will unveil for the metro core something more like Ciena's CoreDirector CI. Mark Lutkowitz, speculates that Cisco may roll out a wavelength switch with STS-1 grooming -- a smaller scale ONS 15900, but with STS-1 granularity and targeted at the metro core instead of the long-haul.

"The metro is their baby," Lutkowitz says. "Cisco doesn't want anything to do with the long-haul. But optical switches belong in the long-haul network. [An optical switch for the metro] doesn't make sense to me."

Indeed, Ciena's CoreDirector CI is a 160G bit/sec non-blocking, bi-directional switch for the long-haul network that supports 64 OC-48/STM-16 or 16 OC-192/STM-64 interfaces, and up to 128 OC-12/STM-4 and OC-3/STM-1 optical interfaces for low speed access. All optical interfaces on the CoreDirector CI can be configured as concatenated for wavelength switching or channelized for grooming and switching at the STS-1 level, Ciena says.

If Cisco plans on unveiling an STS-1-capable wavelength switch, one start-up is ready to take them on. Meriton Networks, which is developing a platform that merges optical add/drop muxing with optical cross-connect capabilities, says Cisco will lack "best-of-breed" capabilities in either wavelength or STS-1 switching, transport and management by mashing the DWDM and SONET capabilities together.

"We don't believe it will be a transparent wavelength service if it's mapped to SONET for switching," says Mike Gassewitz, Meriton president, adding that switching wavelengths at the STS-n level negates bit-rate and protocol independence.

"Our value is a best-of-breed wavelength product and having that work with the best SONET STS-1 products."

One such "best-of-breed" wavelength management feature the Cisco or any wavelength/STS-1 switch will lack is something like Meriton's "bridge-and-roll" failover capability, Gassewitz claims. Bridge-and-roll broadcasts -- or bridges -- a signal across a secondary path in case of failure.

If the primary path fails, the connection is "rolled" over to the secondary path and signal transmission resumes. Path restoration takes between 50 milliseconds and two seconds, Meriton says.

Meriton plans to demonstrate bridge-and-roll on its 7200 Optical Add/Drop Switch at next week's NFOEC show.

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