Lucent Technologies 555-230-024 User Manual

Reliability and Recoverability

Issue 5    January 1998

555-230-024

Critical reliability systems are fully operational over 99 percent of the time, on 
average. No other switch vendor offers this level of system redundancy.

A critical reliability DEFINITY ECS includes:

■

Two control carriers

■

Two tone-clock circuit packs in each port network

■

Two connections between port networks or between Expansion Port 
Networks and the Center Stage Switch

■

Two switch node carriers in center-stage systems

Figure 1-10 shows two control carriers and duplicate fiber-optic cables that con-
nect each port network in a critically reliable, directly-connected system.

1)

Processor Port Network

3)

 Control Carrier

2)

Expansion Port Network

4)

Duplicate Control Carrier

5)

Fiber Optic Cables