Link services IQ (lsq) interfaces that are paired with SONET PICs can use the Automatic Protection Switching (APS) configuration already available on SONET networks to provide failure recovery. SONET APS provides stateless failure recovery, if it is configured on SONET interfaces in separate chassis and each SONET PIC is paired with an AS or MultiServices PIC in the same chassis. If one of the following conditions for APS failure is met, the associated SONET PIC triggers recovery to the backup circuit and its associated AS or MultiServices PIC. The failure conditions are:
The guidelines for configuring SONET APS are described in the JUNOS Network Interfaces Configuration Guide.
The following sections describe how to configure failover properties: