Enterasys Networks BRIM-E6 - Manual (Page 38)

APPENDIX B: EPIM CABLE REQUIREMENTS
Page 34 BRIM-E6 USER’S GUIDE
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 entire network is 25.6
µ
sec, if the total propagation delay between
any two nodes on the network exceeds 25.6
µ
sec, then bridges should be
used.
B.1.3 FOIRL/10BASE-FL Single Mode Fiber Optic Cable
Requirements
Table B-2 shows Single Mode Fiber Optic cable specifications for the
EPIM-F3.
Attenuation
You must test the fiber optic cable with a fiber optic attenuation test set
adjusted for an 1300 nm wavelength. This test verifies that the signal loss
in a cable is 10.0 dB or less for any given single mode fiber optic link.
Fiber Optic Budget and Propagation Delay
Fiber optic budget is the combination of the optical loss due to the fiber
optic cable, in-line splices, and fiber optic connectors. When determining
the maximum fiber optic cable length, the fiber optic budget (total loss of
10.0 dB or less between stations) and total network propagation delay
should be calculated and considered before fiber optic cable runs are
incorporated in any network design.
Table B-2. Single Mode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Cable Length
8/125-12/125
µ
m 10.0 dB or less The maximum allowable fiber
optic cable length is
5 km (3.1 miles) with bridges at
each segment end. However,
IEEE 802.3 FOIRL
specifications specify a
maximum of 1 km (1093.6
yards).