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116
A
PPENDIX
D: C
ABLING
R
EQUIREMENTS
between any two communicating ATM devices and their connectors at
each end.
To determine whether the cable plant complies with the SMF-PMD
standard, do the following:
1
Compare the specifications of the fiber you are using to standard
specifications, as described in Table 29.
2
If you mix equipment supporting Category 1 and Category 2, verify the
maximum attenuation between the equipment, as described in Table 30.
The following pages describe each of these steps and give examples.
Comparing Fiber to
Specifications
Compare the specifications of the fiber you are using to those in Table 29.
If the fiber does not meet the specifications, use a different fiber or
contact 3Com Technical Support.
The single mode PMD specification (SMF-PMD) defines two optical power
categories: Category 1 and Category 2. These categories refer to the
optical power that must be launched into the fiber by the transmitter or
detected by the receiver. 3Com currently supports only Category 1 single
mode fiber.
The specifications for the standard single mode fiber are listed in
Table 29. Refer to the Category 1 specifications in this table for fiber
connecting 3Com equipment. For fiber used with Category 2 equipment
from another vendor, refer to the Category 2 specifications.
The cable plant for a Category 2 implementation must have a minimum
loss of 15.0 dB. In a Category 2 implementation, minimum cable plant
losses are required to avoid saturating (blinding) the receiver.
Table 29
Single Mode Fiber Specifications
Category Specifications Descriptions
Both Categories Core
Cladding
8 to 10 µm
125 µm (
±
2 µm)