A read-write enumeration enabling or disabling payload scrambling on this SONET interface. Payload scrambling randomizes the bit pattern of the SONET payload to prevent long runs of repeated bit patterns that can cause clock recovery or synchronization problems, so both ends of a link must agree on this setting for the link to function correctly. A mismatch in this setting between two connected SONET devices, one with scrambling enabled and the other disabled, would likely cause the link to fail to synchronize properly.