Nortel this week is expected to unveil new switches that it promises will boost resiliency and throughput in enterprise wiring closets.Nortel\u00a0this week is expected to unveil new switches that it promises will boost resiliency and throughput in enterprise wiring closets.The BayStack 5000 is aimed at corporations that want high-density 10\/100\/1000M bit\/sec connections to desktops, and high-speed interconnects among the switches for providing fast uplinks and failover capabilities. For a modular approach to wiring closets, Nortel is offering the PassPort 8300, which promises high-density 10\/100M bit\/sec and Gigabit port densities and power over Ethernet (PoE).The new stackable switch comes in 24- and 48-port versions with all ports capable of supporting 10\/100\/1000M bit\/sec Ethernet connections. The box has two mini Gigabit Interface Converter slots for uplinks to a distribution layer or backbone switch.Nortel is introducing what it calls Flexible Advanced Stacking Technology on the BayStack 5000. The technology uses a proprietary 20G bit\/sec interconnect technology (a derivative of the\u00a0InfiniBand\u00a0standard) to link up to eight stackable switches in a bidirectional loop. Nortel says this architecture can offer faster failover and more bandwidth between switches than competing stacking technologies from 3Com and Cisco. Other features in the switch include Layer 2 to 4 quality of service and traffic shaping, and\u00a0802.1x\u00a0authentication support.The high-availability and security features included in the BayStack 5000 follow a trend toward putting more switching intelligence at the LAN edge, says Joshua Johnson, an analyst with Synergy Research Group."Vendors are putting these features in wiring closet boxes to support new applications," such as IP telephony, instant messaging and IP video, which require low network latency and high bandwidth, Johnson says.Analysts say the BayStack 5000 will compete with Cisco's\u00a0recently announced Catalyst 3750\u00a0and its StackWise technology. Another comparable offering is\u00a03Com's XRN technology\u00a0for tying together fixed-configured boxes at high speeds.As for the PassPort 8300, the product is a revamped PassPort 8600 chassis (a six- or 10-slot box) with a smaller switch fabric. It also uses the base 8600 operating system software reconfigured to support wiring closet deployments, instead of the LAN core or metropolitan-area network edge duties usually associated with the 8600. Blades for the Passport 8300 include a 24- and 48-port 10\/100\/1000M bit\/sec card, and a 48-port blade that supports 802.3af inline power. A specific chassis is required for PoE.The BayStack 5000 is expected to be available in October, priced starting at $5,000. Nortel says a PoE version of the switch is due in the first quarter of next year. The PassPort 8300 is scheduled to be available in October and will start at about $85,000 for a 10-slot chassis, seven PoE modules and redundant power supplies, and switch fabrics.