Chapter 7. Circuit and Network Redundancy61200659L1-1 MX2800 STS-1 User Manual 7-3CIRCUIT FAILURE RECOVERY MODEIn Circuit Failure Recovery Mode, two controller cards are installedand a single STS-1 line is coming in (see Figure 7-2). In this mode,the MX2800 STS-1 can continue operating in the event of acontroller card failure. When both cards are healthy, the primarycard actively processes data while the secondary card stands byready to take over if the first fails. The secondary card continuouslymonitors the line and remains framed to the incoming signal.See Table 7-1 on page 7-4 for a list of this mode’s configurationrequirements.Figure 7-2. Circuit Failure Recovery ModeDuring a card switch, service interruption is experienced on boththe STS-1 and the DSX-1 connections. However, since thesecondary controller card remains framed to the incoming signalat all times, it is a minimal interruption.MX2800 STS-1
