Cabletron Systems TRXI-24 - Manual (Page 19)

REQUIREMENTS/SPECIFICATIONS
Page 2-8
2.1.5 Single Mode Fiber Optic Cable Specifications for the
TPIM-F3
Table 2-7 shows Single Mode Fiber Optic Cable specifications for the
TPIM-F3.
Maximum Trunk Lengths
The maximum trunk cable length between the TRXI and another
active device is equal to the Maximum Drive Distance as shown in
Table 2-7. When the neighboring token ring device is a passive device,
the combined length of twice the longest trunk cable plus the longest
lobe cable attached to the passive ring segment cannot exceed the
Maximum Drive Distance Trunk Length.
Attenuation
The fiber optic cable must be tested with a fiber optic attenuation test
set that is adjusted for a 1300 nm wavelength. This test verifies that
the signal loss in a cable is within an acceptable level of 10 dB or less
for any given single mode fiber optic link.
Fiber Optic Budget
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) should be
calculated and considered before fiber optic cable runs are
incorporated in any network design.
Table 2-7. Single Mode Fiber Optic Cable Specifications
Cable Type Attenuation Maximum Drive Distance
8/125-12/125
µ
m 10.0 dB or less The maximum allowable fiber
optic cable length is 2 km
(2187.2 yards). However,
IEEE 802.5 specifications al-
low for a maximum of 1 km
(1093.6 yards).