Cabletron Systems Inc has added another two bridges, the NB20E and the NB25E, to its range of Ethernet products. The Rochester, New Hampshire company claims that the two-port bridges provide interconnection between IEEE 802.3 Ethernet local area networks implemented using various media, and that they enable users to connect two or more Ethernet segments to create extended-distance local nets. The MAC-level bridges – which, says the company, incorporate the Spanning Tree Algorithm – can use XNS, TCP, LAT or DECnet protocols that run on Ethernetworks; it claims the selectable root switch enables users to preselect the primary data path and reroute traffic without the need physically to relocate bridges. Cabletron says that using a software hashing algorithm, the NB20E can process data at up to 8,700 packets per second, has a forwarding rate of 5,800 packets per second, and is able to store 2,000 nodes in the bridge’s address table; the higher-end NB25E uses a hardware filter to process data at up to 15,000 packets per second with a forwarding rate of 10,000 packets per second, and a storage capacity of 8,000 addresses. The NB20E is priced at $3,000, the NB25E at $6,500; they will be available for shipment in the middle of February.
