Application of attenuators
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Overview
Attenuators (e.g. LC-Line Build-Out or Allwave Attenuators) can be required to ensure
a correct optical power input level, which protects the circuit packs against overload.
Placement
It is preferred to place attenuators at the receiver side (INPUT port), because this is the
furthest physical point on the fiber line from the OUTPUT port and takes the loss of
all connectors into account. If SFPs are used this proposed solution is important in
particular because this causes less level fluctuations if the fibers are moved.
Exception:
If the INPUT port is equipped with a multi-mode pigtail but is a receiver
for single-mode application, the attenuator must be placed at the transmitter side
(OUTPUT port with single-mode pigtail).
Reason: If attenuators for single-mode applications are used on ports with multi-mode
pigtails, the actual attenuation is much lower than the nominal value. In that case the
risk of an overload and damage to the optical receiver is very high.
NOTE:
If the ports are intended for multi-mode application (e.g. Gigabit Ethernet SX
interface, Gigabit Ethernet LX interface with multi-mode application), a multi-mode
attenuator must be used.
Exception:
The Gigabit Ethernet ZX interface is intended only for single-mode
application!
Available LBOs
For a complete and up-to-date list of all available LBOs with the respective comcodes
please refer to the Engineering Drawings ED8C948-10 and ED8C948-20.
System cabling and final assembly
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365-374-187
Issue 1, December 2005
Lucent Technologies - Proprietary
See notice on first page
4-97