This enables or disables carrying low-priority 'extra traffic' on the protection channel during the time it isn't actively protecting a failed working channel, applicable only to the oneToN architecture and required to be disabled if the group uses 1+1 (which has no spare protection-channel capacity to use for extra traffic). An admin might need to disable this specifically for interoperability with other vendors' SONET equipment that doesn't support the extra traffic feature, even on a oneToN group where it would otherwise be usable, and like cApsConfigDirection this can't be changed once the group's row is active. For example, an admin connecting this group's protection channel to an interoperating third-party SONET element that doesn't understand extra traffic signaling would need to set this to disabled to avoid interworking problems, even though the local 1:n architecture would otherwise support carrying it.