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CHAPTER 1 E-Series Overview

The process by which the system switches to the spare line module is called switchover. When switchover occurs, the system:

1Breaks the connection between the primary I/O module and the primary line module.

2Connects the primary I/O module to the spare line module via the redundancy midplane and redundancy I/O module.

Protocol processing then takes place on the spare line module.

Figure 1-15shows the data flow when a spare line module becomes active.

Spare line module

Primary line module

Redundancy

 

g013738

I/O module

Primary

 

Ž

I/O module

Œ

 

 

Midplane

Redundancy midplane

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.

Figure 1-15Data flow when a spare line module is active

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Juniper Networks E-Series manual Spare line module Primary line module