frank: appreciate the warm & fuzzy. i will continue to view birck & co. as the dark horse candidate and sleep with one eye open. interestingly, i recently learned that TLAB's peter guglielmi, exec veep and CFO, is one of five tech reps to JDSU's BoD.
ray: with his pulse on all things optical, here's the latest from our sage, Loring Wirbel.
all my best for an auspicious 2000,
-chris.
postwords: btw, what are we to call this coming decade? the nots? the double o's? less than zeros?
more postwords: mewonders if the Tellium folks are fond of exclaming: "show me the monet!"
sorry i just couldn't resist.
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Electronic Engineering Times
December 20, 1999, Issue: 1092
Section: News
Telecom OEMs deliver 10-Gbit/s optical rates
Loring Wirbel
techweb.com
OCEANPORT, N.J. - Leading telecommunication OEMs staked out competing claims to advanced optical technologies in the 10-Gbit/second range last week. Cisco Systems Inc. rolled out its terabit GSR routers, Lucent Technologies agreed to distribute the Aurora optical cross-connect switch from Tellium Inc. and Ciena Corp. said it has completed interface card prototypes for its MultiWave Metro system.
After laboring for several quarters, Cisco is finally showing the results of its work on packet-over-Sonet interfaces, putting 10-Gbit/s line cards into trials and unveiling a new model of its popular Gigabit Switch Router (GSR) family.
The GSR 12016 system, with 10-Gbit/s line cards and a 320-Gbit/s aggregate capacity, is Cisco's answer to the number of core-router startups that have emerged in the past year.
Cisco is also clarifying the direction it will take for terabit performance in core backbones. The company is developing a 256 x 256 crossbar switching-fabric chassis that will exist as a separate system from its GSR routers. This fabric, which will replace the internal fabric inside the new GSR 12016 router and other members of the family, will allow as many as 16 GSR 12016 routers to be linked into a 5-Tbit/s aggregate route platform.
Graeme Fraser, vice president and general manager of Cisco's optical internetworking business unit, said the new terabit system is not a clustered suite of routers, but rather a true scaled system in which route protocol processing and route table lookup can expand to handle a network of 16 GSR routers. Combined with the new 10-Gbit line cards, the networked switching fabric of routers can support up to 6.4 billion packets/s.
The new line cards will use special very-short-reach optics, implemented as parallel vertical-cavity surface-emitting lasers (VCSELs), to link the GSR 12016 with the Monterey Networks optical cross-connect, or with dense wave division multiplexing (DWDM) equipment from external vendors. It is likely that the network of GSR routers with an external switching fabric will use these in-building, very-short-reach optics as well.
Straightforward scaling
Fraser said that Cisco examined multidimensional router architectures being studied by many startups and concluded they could not scale as straightforwardly as an external switching fabric. Cisco has not closed the door on advanced topologies, Fraser said, but sees the switching-fabric option as the most cost-effective right now.
"It's very true that it's easier to implement an external fabric, but without multidimensionality, it's a whole different ball game in terms of scaling," said Michelle Rae McLean, director of strategic marketing at Pluris Inc. (Cupertino, Calif.) McLean said that Pluris' seven-dimensional multistage fabric can scale in theory to 184 Tbits/s, though such systems will not ship for many quarters. Still, the scaling potential is much greater than for Cisco's GSR 5-Tbit system, she said.
Cisco's 2016, the top of the line in the GSR family, scales to 320 Gbits/s. The 16-slot chassis has an internal 64 x 64 switching fabric with hardware scheduler, which is replaced with a Terabit Scalability Module when the external 256 x 256 fabric is used. The router uses a dedicated Route Processor card to handle table lookup-essentially the same processor used in the earlier 12008 and 12012 GSR routers.
Cisco is using several higher-layer technologies to improve throughput. On each 10-Gbit line card, a feature called Cisco Express Forwarding hands off all advanced-forwarding decisions on a distributed basis, leaving the RP card free to deal only with control plane issues.
Cisco went through two generations of semiconductor company acquisitions to handle the two Sonet rates for packet-over-Sonet. For its OC-48c (2.5-Gbit/s) line cards, Cisco relied on technology from Canadian startup Skystone Corp.
The acquisition of Stratum One Communications Inc. earlier this year was central to completing its OC-192c line cards. Fraser said the ability to support concatenated versions of Sonet rates was critical, since it allows more multiplexing of slower services on broadband Sonet pipes. Qwest Communications International Inc. is conducting nationwide tests of the 10-Gbit cards, though Fraser said they are still many months away from volume production.
Cisco's strategy of interconnecting routers through an external switching fabric, as well as of using short-haul optics to link routers, DWDM multiplexers and optical cross-connects (OXCs), indicate that Cisco executives do not think points of presence and central offices of the future will be dominated by one large route/switch device.
Distributed hardware platforms will be central to all Cisco platforms moving forward, Fraser said. The Monterey OXC, rebranded as the Cisco ONS 15900 Wavelength Router following Cisco's acquisition of Monterey, will be a key element of a network linking routers, IP/ATM switches, and data-aware add-drop muxes from the Cerent portfolio, into a long-haul DWDM backbone.
The launch of "baby gigarouters" such as the M20 from Juniper Networks Inc. earlier this month has raised an important issue as to whether core routers and edge routers are melding into one very high-performance architecture.
Fraser said the notion of melding makes sense in terms of absolute speed, as a 40-Gbit/s router may soon be required at the edge of the public network. But there will always be a difference in the mix of aggregation and forwarding functions required of core routers and edge routers, he said.
For its part, Lucent-which owns a large portfolio of DWDM, Sonet and optical wavelength-selection platforms-plans to combine Tellium's Aurora with its WaveStar Lambda Router to create advanced cross-connect and add-drop multiplexer systems. Introduced last month, the Lambda Router uses arrays of micromirrors to switch wavelengths of light. Under its agreement, Lucent will also sell Tellium's StarNet Restoration Software as well as other management and switching software modules.
Early Monet player
Tellium, a startup spun from Bellcore, was an early participant in the government/industry Multiwavelength Optical Network (Monet) coalition, which provided its founders with insight into next-generation optical transmission platforms. The pact with Lucent is a key milestone in the viability of the young company.
Meanwhile, DWDM specialist Ciena (Linthicum, Md.) said last week that the prototype interface cards for its MultiWave Metro system, which will support 10-Gbit/s speeds across 24 DWDM channels, can be used for traditional Sonet as well as metropolitan Gigabit Ethernet transport. Customer trials of the new systems will not begin until the end of the second quarter of 2000. |
