Cabletron Systems STHI-44 用户手册

 

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This chapter describes network guidelines, power requirements, and 
operating specifications for the STH. Before installing the STH, read this 
chapter and confirm that the network meets the requirements and 
conditions specified in this chapter. Failure to follow these guidelines 
could result in poor network performance.

 

All devices connected to the STH must meet IEEE 802.5 Token Ring 
specifications.

 

The maximum stack composed of four 24-port STH hubs and one 24-port 
intelligent hub offers a total of 120 TCU ports, but the number of ports 
available on the LAN may be increased by the use of passive Multi-
station Access Units (MAUs) (refer to Section 1.2.4, 

 

). The recommended maximum number of 

stations in a single ring is 250 stations when using STP lobe cabling and 
150 stations when using UTP cabling anywhere on the ring. 

 

Crosstalk is interference caused by signal coupling between different 
cable pairs contained within a multi-pair cable bundle. Multi-pair cables 
should not be used for UTP lobe cabling. Avoid mixing Token Ring 
signals with other applications (voice, etc.) within the same cable.

 

Noise can be caused by either crosstalk or externally induced impulses. 
Outside systems (motors, switching equipment, fluorescent lighting, high 
amperage equipment) may produce electrical interference causing noise. 
The number and quality of cable connections also contribute considerably 
to noise levels. If noise induced errors are suspected, it may be necessary