Cabletron Systems SEH-24 User Manual

Also see for SEH-22: User guide

INSTALLATION REQUIREMENTS/SPECIFICATIONSPage 2-52.1.4 Single Mode Fiber Optic Cable Specifications forthe EPIM-F3 ModuleTable 2-2 shows Single Mode Fiber Optic Cable specifications for theEPIM-F3.AttenuationYou must test the fiber optic cable with a fiber optic attenuation testset adjusted for an 1300 nm wavelength. This test verifies that thesignal loss in a cable is 10.0 dB or less for any given single mode fiberoptic link.Fiber Optic Budget and Propagation DelayFiber optic budget is the combination of the optical loss due to thefiber optic cable, in-line splices, and fiber optic connectors. Whendetermining the maximum fiber optic cable length, the fiber opticbudget (total loss of 10.0 dB or less between stations) and totalnetwork propagation delay should be calculated and considered beforefiber optic cable runs are incorporated in any network design.Propagation delay is the amount of time it takes data to travel fromthe sending device to the receiving device. Total propagation delayallowed for the entire network is 25.6 μsec, if the total propagationdelay between any two nodes on the network exceeds 25.6 μsec, thenbridges should be used.Table 2-2. Single Mode Fiber Optic Cable SpecificationsCable Type Attenuation Maximum Cable Length8/125-12/125 μm 10.0 dB or less The maximum allowable fiberoptic cable length is5 km (3.1 miles) with bridgesat each segment end. Howev-er, IEEE 802.3 FOIRL specifi-cations specify a maximum of1 km (1093.6 yards).