Three years after it quit the high-end LAN core market, 3Com this week is set to rejoin the fray with its first backbone switch based on technology from its joint venture partner - embattled data communications vendor Huawei Technology.Three years after it quit the high-end\u00a0LAN\u00a0core market,\u00a03Com\u00a0this week is set to rejoin the fray with its first backbone switch based on technology from its joint venture partner - embattled data communications vendor\u00a0Huawei Technologies.At the CeBit America conference in New York, 3Com is expected to announce its Switch 7700, a seven-slot Layer 3 modular LAN switch, targeted at large companies requiring features such as high-density Gigabit Ethernet and quality of service.3Com also is expected to announce advancements in its Extendable Resilient Networking (XRN) technology, which lets customers tie together smaller switches with high-speed trunks - an architecture the company has touted as being superior to large LAN chassis. New to XRN will be the ability to have 3Com SuperStack 4000 series Gigabit Ethernet switches linked via XRN beyond the previous 300-foot limit to distances of up to 2 miles. This could let companies manage boxes in multiple buildings as a single device, 3Com says.The Switch 7700 will be tested this month at the State of Louisiana Court System in Baton Rouge, which uses a backbone of 3Com 4924 fixed-configuration Gigabit switches, linked with XRN for redundancy. The box could be used as a replacement backbone for the court system's existing LAN or for building new facilities, says Freddie Manint, head of criminal justice IS.The Switch 7700 will compete with products such as\u00a0Cisco's\u00a0Catalyst 6500,\u00a0Extreme Networks'\u00a0BlackDiamond and\u00a0Foundry Networks'\u00a0FastIron chassis switches. While 3Com has not discussed pricing for the 7700, Manint says he expects the switch will cost, on average, around 10% to 25% less than competing products, based on conversations with 3Com.Regarding 3Com's re-emergence into large enterprise chassis switching, Manint says he has no reservations about working with 3Com."3Com didn't get out of the market altogether," he says. "If they had just vanished then tried to re-emerge like this, I'd be more skeptical of them. But we've had great experiences with 3Com."Going forward in its enterprise product push, 3Com faces daunting challenges, observers say. First is assuring large-enterprise IT professionals that they can rely on the company to maintain its LAN core and that they won't see a repeat of 3Com's enterprise switch market exit in 2000. Another will be dealing with potential legal risks 3Com is involved in regarding Cisco's pending intellectual property lawsuit against Huawei, which makes the gear 3Com will sell in the U.S. and abroad.3Com CEO Bruce Claflin said in March that the company is examining all products it will resell from Huawei to ensure that they do not violate the intellectual property. He has said that 3Com's large enterprise strategy will involve. LAN switch products from its Huawei joint venture and 3Com's existing network portfolio, along with carrier-class VoIP and IP telephony products from its former CommWorks carrier arm."As we go forward," Claflin said, "we'll demonstrate that we're a Tier 1 networking company that has a broad line of products for businesses of all sizes."Cisco filed suit against Huawei earlier this year, saying the company violated software patents by copying parts of Cisco's IOS software and plagiarizing Cisco's online documentation.The U.S. District Court for the Eastern District of Texas last week issued a preliminary injunction that said Huawei cannot sell its router operating system containing technology derived from Cisco's Enhanced Interior Gateway Routing Protocol (EIGRP) source code. Huawei also must stop distributing online help files and manuals that are substantially similar to Cisco documentation. The injunction was issued while the court considers other aspects of the patent infringement claims.Huawei said the ruling would not affect its business or its venture with 3Com."Nothing in the preliminary injunction relates at all to new versions of the products," Huawei said in a written statement after the ruling. "Before Cisco initiated its legal action against Huawei, the company had already taken good faith, voluntary action to proactively remove from the U.S. market the obsolete products outlined in the injunction.""Without a doubt, it's a limited victory for Cisco," says Lee Bromberg, senior partner and founder of Bromberg and Sunstein, a Boston law firm specializing in IT intellectual property litigation.3Com last week got involved in the case after the Texas court issued the ruling. The company filed a motion to intervene in the case, effectively jumping in the same boat with Huawei for all related court proceedings."3Com feels they're already in the line of fire," Bromberg says. "As long as that's the case, 3Com's strategy seems to say, 'Let's get in there and help put forward the best case possible,'" against Cisco. Bromberg says that while the near-term implications of the injunction shouldn't affect 3Com-Huawei business, any broader findings of patent infringements by Huawei could come back to haunt 3Com as it begins to offer more gear from the vendor.For now, there shouldn't be any legal caveats regarding the technology in the Switch 7700, says Zeus Kerravala, an analyst at The Yankee Group. The box is a LAN switch, not a router, and will not incorporate functions such as Cisco's EIGRP. However, the release of the 7700 "is a bit of d\u00e9j\u00e0 vu for 3Com," he says, because the product is similar to its former CoreBuilder offerings. But the product was the result of customer demand."When 3Com restructured its business, it focused on stackable switches for [small to midsize businesses] and the enterprise LAN edge," Kerravala says. Now 3Com will have to convince customers it is in the LAN core business for the long haul, by showing a clear road map and delivering products on time. And it is in a good position to do that, he adds."Besides Cisco, 3Com is the only Tier 1 network provider that has no debt and cash in the bank," he says.