LAS VEGAS -- Networld+Interop -- Broadcom Corp. (Nasdaq: BRCM) is getting ambitious with its Gigabit Ethernet switch chips, hoping to expand the devices' reach from the enterprise into service providers' metro networks.

The difference is mostly a matter of features. The company's StrataXGS II chips, announced yesterday at Networld+Interop, add Layer 3 functions such as virtual LAN (VLAN) translation, double VLAN tagging, and Multiprotocol Label Switching (MPLS) tunneling (see Broadcom Smartens Up StrataXGS).

In a way, the chips are a concession to equipment vendors' interest in using merchant Ethernet chips. "A lot of these enterprise devices are finding their way into the metro," says Ford Tamer, VP of Broadcom's networking infrastructure group.

Broadcom isn't the only vendor to tack Layer 3 features onto Gigabit Ethernet chips. Vitesse Semiconductor Corp. (Nasdaq: VTSS) added Layer 3 and MPLS to its Gatwick chip, while SwitchCore AB (Stockholm: SCOR) packed similar features into its Xpeedium2 family (see Vitesse Intros Two GigE Switches and SwitchCore Ships Chips Galore).

In most cases, though, the Layer 3 functions are targeted at enterprise networks. The same is true of the StrataXGS II, but Broadcom is trying to include features to make the chips relevant for the metro market as well.

In that sense, Broadcom appears to have a lead over competitors such as Agere Systems Inc. (NYSE: AGR.A) and Marvell Technology Group Ltd. (Nasdaq: MRVL), according to Simon Stanley, principal analyst with Earlswood Marketing Ltd.

The appeal would be the promise of using one chipset for a variety of platforms. "Companies are looking to build pizza-box kinds of platforms that will go from the [enterprise] workgroup market into the metro, with the same kind of chassis, maybe a 2U- or 3U-high system, but essentially using the same core," Stanley says.But Broadcom still needs a boost in terms of offering a variety of metro services. To that end, it's enlisting some help from network processor vendor Xelerated Inc. At N+I, the companies are demonstrating a reference platform where Xelerated's chips add IPv6 support, VPLS, and extra MPLS functionality to a StrataXGS II switch (see Xelerated, Broadcom Chip In on Ethernet).

In general, Ethernet is getting increased attention as a metro alternative. Equipment vendors such as Atrica Inc. and World Wide Packets Inc. have been pushing the metro Ethernet concept for a few years now. They've gotten some help from the DSL market, particularly in Asia, where backhaul networks use IP or Ethernet rather than Asynchronous Transfer Mode (ATM) (see Siemens Sees Ethernet Everywhere).

"Even the cell phone vendors are moving their networks to Ethernet, which is a big deal. They've got a big ATM legacy," says Broadcom's Tamer.

Among Broadcom's competitors in advanced Ethernet switches will be startup Greenfield Networks, whose switch chip includes MPLS and IPv6 support (see Grand Junction Vets Go Greenfield). But Stanley says Greenfield might have trouble in the metro, because its chip relies on oversubscription -- allowing more traffic to arrive than the chip can handle. The idea, commonly exploited by Cisco Systems Inc. (Nasdaq: CSCO) and others, is that not every port will be full all the time, so that capacity overflows will be rare.

— Craig Matsumoto, Senior Editor, Light Reading