Juniper Networks ERX Hardware 8 - Manual (Page 37)

ERX Overview
Figure 12: Data Flow When a Spare Line Module Is Active
Midplane

Œ
Redundancy
midplane
Spare line module
Primary line module
Redundancy
I/O module Primary
I/O module

Ž
1. A packet arrives at the primary I/O module.
2. The packet passes along the redundancy
midplane from the primary I/O module to
the redundancy I/O module.
3. The packet passes from the redundancy
I/O module to the spare line module.
4. The spare line module processes the packet.
g013738
For information about installing modules for line module redundancy,
see “Installing Modules” on page 35. For information about configuring
and managing SRP module redundancy, see JUNOSe System Basics
Configuration Guide, Chapter 6, Managing Modules.
Power
All E-series routers provide a power architecture that distributes redundant –48 VDC
feeds through the router to each line module, SRP module, and fan module where
DC-to-DC converters provide local conversion to the required secondary voltages.
The ERX-310 router is available with either DC or AC power inputs. The AC-powered
version can be configured with one or two hot-swappable power supplies for optional
redundancy. (See Figure 5 and Figure 6.) The power supplies convert AC power to
internal –48 V redundant DC feeds that are then distributed through the router.
Redundancy Features 19