Copper Cable Specifications For Qfx5100-48T Switches; Table - Juniper QFX5100 Hardware Manual

Table 55: Estimated Values for Factors Causing Link Loss (continued)
Link-Loss Factor
Splice
Fiber attenuation
Clock Recovery Module
(CRM)
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Documentation

Copper Cable Specifications for QFX5100-48T Switches

Copyright © 2016, Juniper Networks, Inc.
Estimated Link Loss Value
0.5 dBm
Multimode—1 dBm/km
Single-mode—0.5 dBm/km
1 dBm
NOTE: For information about the actual amount of signal loss caused by
equipment and other factors, see your vendor documentation for that
equipment.
Calculate the (P ) by subtracting (LL) from (P
2.
M
P – LL = P
B M
13 dBm – 0.5 dBm [HOL] – 5 (0.5 dBm) – 2 (0.5 dBm) – 2 km (1.0 dBm/km) – 1 dB
[CRM] = P
M
13 dBm – 0.5 dBm – 2.5 dBm – 1 dBm – 2 dBm – 1 dBm = P
P = 6 dBm
M
The calculated power margin is greater than zero, indicating that the link has sufficient
power for transmission. Also, the power margin value does not exceed the maximum
receiver input power. Refer to the specifications for your receiver to find the maximum
receiver input power.
Understanding QFX Series Fiber-Optic Cable Signal Loss, Attenuation, and Dispersion
on page 150
The QFX5100-48T switches have 10GBASE-T interfaces that use various types of copper
network cables. To achieve optimal performance, you must use cables that conform to
IEEE 802.3-2012 specifications for connections for 10GBASE-T network ports.
Table 56 on page 154 lists the cable specifications for 10GBASE-T port on QFX5100-48T
switches.
Chapter 9: Cable Specifications
Sample Link Loss (LL) Calculation Values
This example assumes two splices. Loss for two splices:
2 (0.5 dBm) = 1 dBm.
This example assumes the link is 2 km long. Fiber
attenuation for 2 km: 2 km (1 dBm/km) = 2 dBm.
This example assumes the link is 2 km long. Fiber
attenuation for 2 km: 2 km (0.5 dBm/km) = 1 dBm.
1 dBm
):
B
M
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