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Technology Stocks : Broadcom (BRCM) -- Ignore unavailable to you. Want to Upgrade?

To: Brian Malloy who wrote (3853)	4/27/2000 1:17:00 PM
From: jackmore	Read Replies (2) \| Respond to of 6531

More on the G-Switch: Broadcom, MMC expand switch chip portfolios By Loring Wirbel EE Times (04/26/00, 12:36 p.m. EST) IRVINE, CALIF. ? At the upcoming Spring Networld+Interop (May 8-10) new switch chip architectures from Broadcom and MMC Networks will be reflecting the broader range of applications for switching semiconductors operating at Layers 2 and 3 in the Open Systems Interconnect protocol stack. Broadcom Corp. (Irvine) is fielding what it calls the first true single-chip eight-port Gigabit Ethernet switch with integrated packet filtering and quality-of-service prioritizing. The BCM5680 G-Switch's sampling schedule coincides with the production release of the BCM5400, claimed to be the first Gigabit Ethernet transceiver for copper (Category 5 unshielded twisted pair). MMC Networks Inc. (Sunnyvale, Calif.), meanwhile, is expanding the design capabilities of the nP 7120 processor, launched in late winter. The company is adding TCP snooping and gigabit port expansion capabilities to the 7120 to respond to the new interest in "Web switching." Broadcom worked to be first in both the number of ports and the integration of medium access control (MAC) and transceiver functions for Ethernet and Fast Ethernet, so its integration lead with the BCM5680 is no surprise. Each of the eight ports on the device can be used for the 10-, 100- or 1,000-Mbit/second speeds of Ethernet, allowing unique mixes of 10/100 ports and Gigabit Ethernet uplinks. Multiple devices can be stacked to support up to 30 devices, and multiple ports can be aggregated to create faster channels. The new G-Switch represents the first all-gigabit member of the StrataSwitch family, which offers several buffering and prioritizing features for packets. Since all ports have local buffering, there is no need for external memory with the G-Switch. Packets can be filtered at any Layer from 3 to 7. Broadcom implements proprietary classification algorithms it calls ContentAware traffic conditioning, which can rank packet traffic according to four Internet Protocol service classes. "All address resolution tables and all class-of-service queues are on the chip, so it has no memory interface. You don't need external memory," said product line manager Jim Finch. The predecessor to the companion BCM5401, the BCM5400, was discussed last year, when Broadcom revealed it was using a DSP-based transceiver architecture in 0.22 digital CMOS technology. But in moving to full volume in a copper gigabit transceiver, Broadcom claims it has beat Intel/Level One and other players to market, providing a device that exceeds IEEE 802.3ab specs. The 5401 meets both Gigabit Media Independent Interface and 10-bit interface-to-magnetics specs, and it offers full autonegotiation to support Ethernet, Fast Ethernet and Gigabit Ethernet links. Yossi Cohen, director of marketing at Broadcom, said that the shift to smaller feature sizes allows Broadcom to move to lower power dissipation in the 5401 vs. the 5400. The new device also improves bit-error rate performance through enhanced signal-processing blocks on chip. The new transceiver can auto-detect for wiring problems such as swapped pairs, pair skews, reversed polarity and MDI crossover. The DSP core in the transceiver can be used as an in-line cable tester. The BCM5401, packaged in a 256-pin thin ball-grid array, is available now at $50 each. The BCM5680 switch samples this month in a 400-pin TBGA and will sell for $200 each in volume. MMC, meanwhile, is expanding the content-switching duties for its nP 7120, promoting general design principles that already have been realized by such MMC customers as Arrowpoint Communications Inc. System vendors like Foundry Networks Inc. and Alteon Websystems Inc. led the charge in what became known as content or application-aware switching. The technique uses ASICs to make Ethernet switching more intelligent in balancing Web traffic, both within an enterprise and for Web hosts that link with the public Internet. MMC is bringing the capability to standard silicon with the addition of two features to the nP 7120, which began sampling in March. The chip is now equipped with special gigabit port expansion and Transmission Control Protocol "spoofing" capabilities. Since TCP port assignment is central to Layer 4 switching, providing a spoof method for the host processor is critical to providing the most straightforward use of parsing power. Simon Milner, product line manager for the 7120, said TCP port assignment functions for HTTP redirection or content switching can be handled by the 7120 on its own. Once designs move to user resource locator switching or "cookie switching," however, MMC recommends using the 7120 in conjunction with deeper search engines and packet classifiers. MMC already has a partner relationship with SwitchOn Systems Inc. and will talk to others about joint classifier designs. That "Lego" methodology, marketing director Robin Melnick said, avoids the problem that a more integrated network processor might have in adding content-switching features beyond Layer 4. When the 7120 is used in two-port bidirectional Gigabit Ethernet applications, the policy engine still has at least 50 percent code space for advanced traffic management algorithms. eetimes.com