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Technology Stocks : Lucent Technologies (LU) -- Ignore unavailable to you. Want to Upgrade?

To: jach who wrote (4977)	11/15/1998 5:43:00 PM
From: pat mudge	Respond to of 21876

I apologize if this was discussed earlier: <<<< Lucent puts Simple Data Link into silicon via Detroit chip set By Loring Wirbel EE Times (11/13/98, 1:50 p.m. EDT) ALLENTOWN, Pa. — Lucent Microelectronics took two key steps this week toward uniting the burgeoning worlds of Internet Protocol and optical networking. Lucent formally proposed to the Internet Engineering Task Force a standard, dubbed Simple Data Link (SDL), to put IP packets directly on an optical layer. It also announced it was sampling its Detroit (Data encapsulation and transport overhead device for point-to-point interface termination) chip set, the first silicon to implement SDL. The Detroit set could find a home among large router designs that marry Internet traffic with the fiber-optic backbone network. SDL puts IP packets on an optical layer without intervening Sonet frames or High-level Data Link Control (HDLC) encapsulation. In addition to being the first chip set to implement SDL, Detroit is also the first to truly offer packet-over-wavelength division multiplexing without an underlying Sonet frame, said Paul Langner, chief architect. But Detroit also can be used for ATM-over-WDM, IP-over-Sonet, or IP-over-ATM-over-Sonet-over-WDM — in fact, the CMOS chips can be used to support multiple protocol-stack options in one system. Lucent first hinted at its SDL work in the closing presentation at the National Fiber Optics Engineering Conference in Orlando, Fla., two months ago. Since then, the microelectronics division worked with router startup IronBridge Inc. to submit a formal proposal to the Point-to-Point Protocol Extensions Working Group within IETF. The proposal calls for a link that combines IP packets with a 16-bit Cyclic Redundancy Check and simple scrambler, allowing the minimum possible overhead for transmitting IP. Jim Johnston, Sonet and switching marketing manager, emphasized that additional IP header fields, such as Multi-Protocol Label Switching tag fields or IP Multicast fields, can be appended to SDL, so use of SDL does not restrict users from adding IP Quality of Service or multicasting functions. Two devices The first two devices in the Detroit family to implement SDL are the TDAT042G5 and TDA04622 Sonet and Synchronous Digital Hierarchy section/line termination devices. The 42G5 terminates four separate OC-3 (155-Mbit) or OC-12 (622-Mbit) interfaces, or a single OC-48 (2.5-Gbit) interface. The 4622 terminates a single OC-12 or up to four OC-3 interfaces. Though the devices are specified as Sonet/SDH line termination for customer-comprehension reasons, Langner said they are the first in the industry to allow packet transport on optical fiber without any form of Sonet Payload Envelope or HDLC framing. However, the Detroit chips can implement the designer's choice of SDL, ATM or HDLC framing. The two devices interface directly to the Lucent TMD2G5 series of 2.5-Gbit transceiver devices. In the past, that would have meant a very integrated implementation of a traditional telephony line card. Now, however, Lucent is taking requests from large router manufacturers for designs that will find homes in Internet service provider Points of Presence, as well as phone company central offices. "We will be providing a full suite of packet-over-Sonet solutions as well," said Greg Waters, recently named vice president and general manager of Lucent Micro's networking and communications products group. "Often, the protocol stack chosen depends on whether our customers are designing products for an RBOC [regional Bell operating company], a competitive carrier, a foreign PTT or an ISP." In the future, Lucent plans to add cross-connect functionality to the Detroit family to provide true Add-Drop Multiplexer functions on a chip, to appeal to Sonet traditionalists. But SDL-oriented Detroit devices may prove to be the designs of choice for router and packet-switch companies moving directly to packet over WDM. As for interfacing the chips directly with the systems coming from Bell Labs that implement dense WDM channels through passive waveguides, Langner pointed out that the two groups still represent different divisions within Lucent, but added, "obviously, we stay in very close contact about how our advances may come to mutual advantage." >>>>