Cabletron Systems HubSTACK SEHI-34 User Manual

Also see for HubSTACK SEHI-34: Addendum

Contents

INTRODUCTIONPage 1-3The SEHI-22/24 and SEHI-32/34 are functionally identical with theexception of the network ports:• SEHI-22, 12 RJ45 network ports and one EPIM port.• SEHI-24, 24 RJ45 network ports and two EPIM ports.• SEHI-32, one 50 pin Champ connector, providing 12 twistedpair segments, and one EPIM port.• SEHI-34, two 50 pin Champ connectors, providing 24 twistedpair segments, and two EPIM ports.1.4 SEHI FEATURESRepeater FunctionalityThe SEHI fully conforms to the IEEE 802.3 Repeater, AUI, and10BASE-T specifications, and provides the flexibility to connectnetworks using IEEE 802.3, Ethernet Version 1 or Version 2equipment. The SEHI transmits re-timed data packets, regeneratesthe preamble, extends fragments, and arbitrates collisions.The SEHI automatically partitions problem segments, and reconnectsrepaired segments to the network. This feature minimizes the impacton network operation resulting from a problem on one segment byisolating the problem segment. Only devices on the problem segmentare affected. When the problem is solved, the SEHI automaticallyreconnects the isolated segment to the network.Polarity Detection and CorrectionEach twisted pair port on the SEHI incorporates a Polarity Detectionand Correction feature that allows the SEHI to pass data regardless ofthe polarity of the twisted pair segment’s receive link. We do notrecommend operating in this condition. If you discover this condition,remove the segment from the network and wire it correctly. Thisreduces the potential for problems if equipment changes are made.Flash EEPROMsThe SEHI uses Flash EEPROMs that allow you to download new andupdated firmware using Cabletron’s Remote LANVIEW/Windows,version 2.3 or later or any device using BOOTP or TFTP protocols.