Routing Engine Interface Cable Specifications For Mx5, Mx10, Mx40, And Mx80 Routers; Table 38: Cable Specifications For Routing Engine Management - Juniper MX5 Hardware Manual

Table 37: Estimated Values for Factors Causing Link Loss (continued)
Link-Loss Factor
Fiber attenuation

Routing Engine Interface Cable Specifications for MX5, MX10, MX40, and MX80 Routers

Copyright © 2019, Juniper Networks, Inc.
Estimated Link-Loss Value
Single-mode—0.5 dB/km
Multimode—1 dB/km
The following sample calculation for a 2-km-long multimode link with a power budget
(P ) of 13 dB uses the estimated values from
B
(LL) as the sum of fiber attenuation (2 km @ 1 dB/km, or 2 dB) and loss for five connectors
(0.5 dB per connector, or 2.5 dB) and two splices (0.5 dB per splice, or 1 dB) as well as
higher-order mode losses (0.5 dB). The power margin (P
P = P – LL
M B
P = 13 dB – 2 km (1 dB/km) – 5 (0.5 dB) – 2 (0.5 dB) – 0.5 dB
M
P = 13 dB – 2 dB – 2.5 dB – 1 dB – 0.5 dB
M
P = 7 dB
M
The following sample calculation for an 8-km-long single-mode link with a power budget
(P ) of 13 dB uses the estimated values from
B
(LL) as the sum of fiber attenuation (8 km @ 0.5 dB/km, or 4 dB) and loss for seven
connectors (0.5 dB per connector, or 3.5 dB). The power margin (P
follows:
P = P – LL
M B
P = 13 dB – 8 km (0.5 dB/km) – 7(0.5 dB)
M
P = 13 dB – 4 dB – 3.5 dB
M
P = 5.5 dB
M
In both examples, the calculated power margin is greater than zero, indicating that the
link has sufficient power for transmission and does not exceed the maximum receiver
input power.
Table 38 on page 71 lists the specifications for the cables that connect to management
ports.

Table 38: Cable Specifications for Routing Engine Management

Cable
Port Specification
Routing Engine RS-232
console or (EIA-232) serial
auxiliary cable
interface
Chapter 2: Site Planning, Preparation, and Specifications
Table 37 on page 70
) is calculated as follows:
M
Table 37 on page 70
Cable/Wire Maximum
Supplied Length
One 6-ft 6 ft (1.83 m)
(1.83-m) length
with RJ-45/DB-9
connectors
to calculate link loss
to calculate link loss
) is calculated as
M
Router
Receptacle
RJ-45 female
71