Routers; Table 40: Cable And Wire Specifications For Routing Engine Management And - Juniper MX480 Hardware Manual

MX480 3D Universal Edge Router Hardware Guide
Routing Engine Interface Cable and Wire Specifications for MX Series Routers
288
Higher-order mode loss = 0.5 dB
Clock recovery module = 1 dB
The power margin ( ) is calculated as follows:
P
M
P = P – LL
M B
P = 13 dB – 2 km (1.0 dB/km) – 5 (0.5 dB) – 2 (0.5 dB) – 0.5 dB [HOL] – 1 dB [CRM]
M
P = 13 dB – 2 dB – 2.5 dB – 1 dB – 0.5 dB – 1 dB
M
P = 6 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
( ) as the sum of fiber attenuation (8 km @ 0.5 dB/km, or 4 dB) and loss for seven
LL
connectors (0.5 dB per connector, or 3.5 dB). The power margin (
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 40 on page 288 lists the specifications for the cables that connect to management
ports and the wires that connect to the alarm relay contacts.
Table 40: Cable and Wire Specifications for Routing Engine Management
and Alarm Interfaces
Cable
Port Specification
Routing Engine RS-232
console or (EIA-232) serial
auxiliary cable
interface
Routing Engine Category 5 cable
Ethernet or equivalent
interface suitable for
100Base-T
operation
Table 39 on page 287
Cable/Wire Maximum
Supplied Length
One 6-ft 6 ft (1.83 m)
(1.83-m) length
with RJ-45/DB-9
connectors
One 15-ft 328 ft (100 m)
(4.57-m) length
with
RJ-45/RJ-45
connectors
Copyright © 2011, Juniper Networks, Inc.
to calculate link loss
P ) is calculated as
M
Router
Receptacle
RJ-45 female
RJ-45
autosensing