Juniper MX960 Hardware Manual page 174

Component/Feature
GPS port
External clock interface
Centralized Stratum3E
clock module
In-system removable
Routing Engine
Hot-Swappable
System upgrade capabilities
Redundancy
DMR
GRES
MPC line cards
Hitless Operation
Description
One RJ-45 GPS external clock interface port receives GPS and PPS timing from the GPS
external interface. A red LED indicates there is no clock present or the clock is not OK.
A green LED indicates the clock interface is active and OK. If the LED is off, the clock
interface is not enabled.
The external clock interface is on the SCBE3-MX front panel. The clock source interface
receives GPS and PPS timing from the GPS external interface.
The clock module performs clock monitoring, filtering, and holdover on the centralized
fabric card. This centralized clocking architecture also provides clock cleanup and
distribution.
The in-system Routing Engine can support any new Routing Engine that conforms to
the standard modular Routing Engine I/O interface and form factor.
NOTE: When a Routing Engine is not installed in the SCBE3-MX, you need to cover the
empty slot with a blank panel.
The SCBE3-MX and associated Routing Engine assembly are hot-swappable. The system
software provides a mechanism to shut down, or acquiesce the Routing
Engine/SCBE3-MX. The system software also provides a method to reset or reboot the
Routing Engine/SCBE3-MX. This support is provided via cli commands, and various
hardware support circuits.
NOTE: The Routing Engine must be brought offline prior to removal to avoid possible
corruption of the hard drive.
See "Upgrading an MX240, MX480, or MX960 Router to Use the SCBE3-MX" on
page 583for details.
With three SCBE3-MX's installed, the MX960 router provides 2 + 1 redundancy. With
two SCBE3-MX's installed, the MX240 router and MX480 router provide 1 + 1
redundancy.
Supports Dynamic Multicast Replication (DMR)
Supports Graceful Routing Engine Switchover (GRES)
Supports the MPCs listed in
Allows you to upgrade programmable parts and reboot with "hitless" operation if the
redundant SCBE3-MX's are inserted in the system and are operational.
Table 72 on page 155.
152