An internal switch bridges the two segments so the devices can communicate while running at either speed. The Medium Dependent Interface switchable port permits simple cascading of hubs, switches or downlinks without a special crossover cable. The MDI and MDI-X ports are used together on the different hubs to be connected. A few manufacturers require that at least one of the hubs in a stack be a managed hub. Others sell various slave or client models for use with a single master unit within the stack.
Some stackable hubs come with standard management packages.
Others come with optional management modules that include SNMP support for four Remote Network Monitoring protocol groups events, alarms, history and statistics and browser-based Web management features. Many stackable hubs are modular and customizable, allowing users to add extra 100-BaseFX fiber Fast Ethernet WAN links or management modules. J.B. Miles of Pahoa, Hawaii, writes about communications and computers. Inc. All rights reserved.