Cabletron Systems TRFMIM-22 User Manual

Contents

REQUIREMENTS/SPECIFICATIONS2-2• Attenuation - The fiber optic cable must be tested with a fiberoptic attenuation test set that is adjusted for an 850 nmwavelength. This test verifies that the signal loss in a cable iswithin an acceptable level:- 13.0 dB or less for 50/125 fiber cable segment.- 16.0 dB or less for 62.5/125 fiber cable segment.- 19.0 dB or less for 100/140 fiber cable segment.• Budget and Propagation Delay - When determining themaximum fiber optic cable length, the fiber optic budget delayand total network propagation should be calculated and takeninto consideration before fiber optic cable runs are incorporatedin any network design. Fiber optic budget is the combination ofthe optical loss due to the fiber optic cable, in-line splices, andfiber optic connectors. Propagation delay is the amount of timeit takes a packet to travel from the sending device to thereceiving device.• Length - The maximum allowable fiber optic cable length is2 km.2.3 OPERATING SPECIFICATIONSThis section describes the operating specifications for each of thefiber optic token ring concentrator modules. Cabletron Systemsreserves the right to change these specifications at any time withoutnotice.2.3.1 Ring SpeedThe concentrator module ring speed can be set to default to either 4Mbit/s or 16 Mbit/s. The ring speed is automatically set to a defaultsetting at power on. The default ring speed can be selected bypositioning a network speed jumper on the board (Refer to Chapter3, Installing the Concentrator Module, to learn how to set thenetwork speed jumper.) The default setting can be overridden bychanging the ring speed through local or remote networkmanagement software.