Cabletron Systems SEHI100TX-22 manual Multimode Fiber Optic Cable Specifications, Propagation Delay

Models: SEHI100TX-22

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Propagation Delay

Cable Specifications

Propagation Delay

Propagation delay is the amount of time it takes data to travel from the sending device to the receiving device. Total propagation delay allowed for the network is 256 bit times (2.56 s) in one direction (5.12 s round trip). If the total propagation delay between any two nodes on the network exceeds 2.56 s, then use bridges or other devices to further segment the network.

Temperature

The attenuation of PVC insulated cable varies significantly with temperature. At temperatures greater than 40°C (104°F), Cabletron Systems recommends the use of plenum-rated cables to ensure that cable attenuation remains within specification.

3.1.3Multimode Fiber Optic Cable Specifications

The SEHI supports the Cabletron Systems EPIM-100FX and EPIM-100FMB. These EPIMs meet IEEE 802.3u standards. When connecting a fiber optic segment to the SEHI EPIM-100FX or EPIM-100FMB module, the network must meet the following requirements:

Cable Loss

Test the fiber optic cable with a fiber optic attenuation test set adjusted for an 850 nm wavelength. This test verifies that the signal loss in a cable is within an acceptable level. The maximum loss for a multimode fiber optic cable is 11.0 dB.

Fiber Optic Budget and Propagation Delay

Determine the maximum fiber optic cable length by calculating the fiber optic budget delay and total network propagation before fiber optic cable runs are incorporated in any network design.

Fiber optic budget is the combination of the optical loss due to the fiber optic cable, in-line splices, and fiber optic connectors.

SEHI100TX User’s Guide

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Cabletron Systems SEHI100TX-22 manual Multimode Fiber Optic Cable Specifications, Propagation Delay, Temperature, Cable Loss