This read-only field stores the failure reason code for side B of an ATM PVC connection, documenting what error condition prevented the circuit from becoming active. Operations teams reference this code to understand whether the far-end gateway is unreachable, lacks required resources, or has a configuration conflict. For instance, a code like 'peer-not-responding' tells the operator that the remote gateway is not answering connection requests, whereas 'bandwidth-unavailable' means the far end ran out of trunk bandwidth.