Scg Slots; Scg Function; Scg Redundancy; Supported Scgs - Juniper T4000 Hardware Manual

T4000 Router Hardware Guide
50

SCG Slots

The SCGs are installed into the upper rear of the chassis in the slots labeled
.
SCG1

SCG Function

SCGs provide 19.44-MHz Stratum 3 clock signal for the SONET/SDH interfaces on the
router.

SCG Redundancy

One SCG is shipped as part of the standard router configuration, but up to two SCGs can
be installed to provide redundancy. A nonredundant SCG is hot-pluggable. For redundant
SCGs, the master SCG is hot-pluggable. If the master SCG is functioning, the backup
SCG is hot-removable and hot-insertable. Removing the backup SCG does not affect
the functioning of the router. Taking the master SCG offline might result in a brief loss of
SONET clock lock while the backup SCG becomes the master.

Supported SCGs

The T4000 router supports the SCG in
NOTE: Redundant SCGs must be the same model number, except during
upgrade.

Table 23: Supported SCG

Name
SCG with RJ-48 ports
SCG with DB-9 ports

SCG Components

The SCG with DB-9 ports is shown in

Figure 27: SCG with DB-9 Ports

Table 23 on page 50.
Model Number
SCG-T-EC
SCG-T
Figure 27 on page 50.
Copyright © 2013, Juniper Networks, Inc.
and
SCG0
First Supported Junos OS
Release
12.1
12.1