Cabletron Systems SEHI SEHI100TX- User Manual

Also see for SEHI100TX-22: User guide User guide

Contents

Cable SpecificationsSEHI100TX User’s Guide3-3Propagation DelayPropagation delay is the amount of time it takes data to travel from thesending device to the receiving device. Total propagation delay allowedfor the network is 256 bit times (2.56 μs) in one direction (5.12 μs roundtrip). If the total propagation delay between any two nodes on the networkexceeds 2.56 μs, then use bridges or other devices to further segment thenetwork.TemperatureThe attenuation of PVC insulated cable varies significantly withtemperature. At temperatures greater than 40°C (104°F), CabletronSystems recommends the use of plenum-rated cables to ensure that cableattenuation remains within specification.3.1.3 Multimode Specifications for the EPIM-100FXThe SEHI supports the Cabletron Systems EPIM-100FX. TheEPIM-100FX meets IEEE 802.3u standards. When connecting a fiberoptic segment to the SEHI EPIM-100FX module, the network must meetthe following requirements:Cable LossTest the fiber optic cable with a fiber optic attenuation test set adjusted foran 850 nm wavelength. This test verifies that the signal loss in a cable iswithin an acceptable level. The maximum loss for a multimode fiber opticcable is 11.0 dB.Fiber Optic Budget and Propagation DelayDetermine the maximum fiber optic cable length by calculating the fiberoptic budget delay and total network propagation before fiber optic cableruns are incorporated in any network design.Fiber optic budget is the combination of the optical loss due to the fiberoptic cable, in-line splices, and fiber optic connectors.Propagation delay (collision delay) is the amount of time it takes data totravel from the sending device to the receiving device. Total propagationdelay allowed for the entire network is 256 bit times (2.56 μs) in onedirection (5.12 μs round trip). If the total propagation delay between anytwo nodes on the network exceeds 2.56 μs, then use bridges or otherdevices to further segment the network.