7-2 61200290L1-1GSection 7, Circuit and Network Redundancy MX2800 M13 Multiplexer User ManualNOTEIn this mode, the DS3 must be connected to the IN and OUT jacks forDS3 A.3. CIRCUIT FAILURE RECOVERY MODEIn Circuit Failure Recovery Mode, two controller cards are installed with an incoming single DS3 line. SeeFigure 7-2 on page 7-2. In this mode, the MX2800 can continue operating in the event of a controller cardfailure. When both cards are healthy, the primary card actively processes data while the secondary cardstands by and is ready to take over if the first fails. The secondary card continuously monitors the line andremains framed to the incoming signal.NOTEDuring a card switch, service interruption occurs on both the DS3 and theDSX1 connections. However, since the secondary controller card remainsframed to the incoming signal at all times, it is a minimal interruption.Figure 7-2. Circuit Failure Recovery ModeSee Table 7-1 for a list of this mode’s configuration requirements.Table 7-1. Configuration Requirements for Circuit RecoverySelection Path Recommended SettingConfig > Network Interface > XCV Threshold 1E-3 *Config > Network Interface > Network Protection DisabledConfig > Network Interface > Max. Switch Threshold 3
