The architecture and mode of the APS group. The values mean: onePlusOne The 1+1 architecture permanently bridges the working line to the protection line. oneToN The 1:n architecture allows one protection channel to protect up to n working channels. When a fault is detected on one of the n working channels that channel is bridged over the protection channel. Note: onePlusOne and oneToN are mutually exclusive. revertive When the condition that caused a switch to the protection line has been cleared the signal is switched back to the working line. If this bit is clear it indicates a non-revertive system which remains on the protection line until another switch request is received. bidirectional The bi-directional mode provides protection in both directions. If this bit is clear it indicates unidirectional mode which provides protection in one direction. The default for 1:n is bidirectional. The default for 1+1 is unidirectional. extraTrafficAllowed Extra traffic may be carried on the protection channel in a 1:n architecture if this flag is set. It may be necessary to disable this in order to interwork with other SONET network elements that don't support extra traffic. This object may not be modified if the associated apsConfigRowStatus object is equal to active(1).